Costco Transportation Impact Analysis

COSTCO WHOLESALE ALEXANDRIA/MOUNT VERNON

TRAFFIC IMPACT ANALYSIS FAIRFAX COUNTY, VIRGINIA

Submitted on behalf of: Costco Wholesale

Prepared by: Wells + Associates, Inc.

Robin L. Antonucci

Priyatham Konda, P.E. 703.365.9262

& Kevin R. Fellin, P.E.

John F. Cavan 703.917.6620

August 23, 2010

Costco Wholesale – Alexandria/Mount Vernon Traffic Impact Analysis

Fairfax County, Virginia

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TABLE OF CONTENTS PAGE EXECUTIVE SUMMARY ____________________________________________________________ i

PURPOSE OF REPORT & STUDY OBJECTIVES ...............................................................................................................i SITE LOCATION AND STUDY AREA .............................................................................................................................i DESCRIPTION OF PROPOSED DEVELOPMENT .............................................................................................................i PRINCIPAL FINDINGS .....................................................................................................................................................i RECOMMENDATIONS .................................................................................................................................................. iii Section 1 INTRODUCTION _________________________________________________________________ 1 STUDY OBJECTIVES ...................................................................................................................................................... 1 STUDY AREA .......................................................................................................................................................... 2 FIGURE 1-1: LIMITS OF STUDY AREA ......................................................................................................... 3 TABLE 1-1: INFLUENCE AREA ..................................................................................................................... 4 STUDY METHODOLOGY ...................................................................................................................................... 4 Section 2 BACKGROUND INFORMATION ___________________________________________________ 5 SITE LOCATION/DESCRIPTION ................................................................................................................................... 5 OVERVIEW ............................................................................................................................................................. 5 FIGURE 2-1: SITE LOCATION MAP ............................................................................................................. 6 TERRAIN ................................................................................................................................................................. 5 EXISTING ZONING ............................................................................................................................................... 5 NEARBY USES ........................................................................................................................................................ 5 FIGURE 2-2: EXISTING ZONING ................................................................................................................. 7 SITE ACCESS ........................................................................................................................................................... 5 FIGURE 2-3: PROPOSED PLAN REDUCTION ............................................................................................. 8 COMPREHENSIVE PLAN – LAND USE RECOMMENDATIONS ........................................................................... 9 ROADWAY NETWORK ........................................................................................................................................ 9 EXISTING ROADWAY NETWORK ............................................................................................................... 9 FIGURE 2-4: EXISTING LANE USE AND TRAFFIC CONTROL ......................................................... 10 FUTURE ROADWAY NETWORK ................................................................................................................ 11 PLANNED/PROGRAMMED IMPROVEMENTS............................................................................................... 12 FIGURE 2-5: COMPREHENSIVE PLAN RECOMMENDATIONS (TRANSPORTATION – NORTH

AREA) .................................................................................................................................................... 13 FIGURE 2-6: COMPREHENSIVE PLAN RECOMMENDATIONS (TRANSPORTATION – SOUTH

AREA) .................................................................................................................................................... 14 ROUTE 1 LOCATION STUDY ..................................................................................................................... 12 TRANSIT FACILITIES ............................................................................................................................................ 12 FAIRFAX CONNECTOR ............................................................................................................................... 12 WMATA METROBUS ................................................................................................................................. 13



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Section 3 ANALYSIS OF EXISTING CONDITIONS __________________________________________ 16 TRAFFIC VOLUMES ..................................................................................................................................................... 16 FIGURE 3-1: EXISTING PEAK HOUR TRAFFIC VOLUMES ............................................................................... 17 FIGURE 3-2: EXISTING PEAK HOUR PEDESTRIAN VOLUMES ........................................................................ 18 OPERATIONAL ANALYSIS .......................................................................................................................................... 16 TABLE 3-1: EXISTING LEVELS OF SERVICE ....................................................................................................... 20 FIGURE 3-3: EXISTING LEVELS OF SERVICE ..................................................................................................... 21 Section 4 ANALYSIS OF FUTURE CONDITIONS WITHOUT DEVELOPMENT ________________ 22 METHODOLOGY ......................................................................................................................................................... 22 REGIONAL GROWTH ......................................................................................................................................... 22 FIGURE 4-1: 2013 REGIONAL GROWTH FOR BUILD OUT ................................................................... 23 FIGURE 4-2: 2019 REGIONAL GROWTH FOR BUILD OUT ................................................................... 24 PIPELINE PROJECTS .............................................................................................................................................. 22 FIGURE 4-3: LOCATIONS OF PIPELINE DEVELOPMENTS ........................................................................ 25 FIGURE 4-4: SUMMARY OF THE BRAC PREFERRED ALTERNATIVE: NEW AND RENOVATED PIPELINE DEVELOPMENTS ................................................................................ 26 FIGURE 4-5: LOCATION OF THE BRAC PREFERRED ALTERNATIVE: NEW AND RENOVATED ............................................................................................................................ 27 FIGURE 4-6: BRAC TRIP ASSIGNMENTS .................................................................................................. 29 FIGURE 4-7: PLANNED FUTURE LANE USE AND TRAFFIC CONTROL WITHOUT DEVELOPMENT ... 30 FIGURE 4-8: MOUNT VERNON GATEWAY TRIP ASSIGNMENTS .......................................................... 31 FIGURE 4-9: 2019 TRAFFIC REDISTRIBUTIONS FOR RIGHT-IN, RIGHT-OUT BUCKMAN ROAD ..... 32 FUTURE TRAFFIC VOLUMES WITHOUT THE SITE DEVELOPMENT ................................................................. 28 PIPELINE DEVELOPMENTS ................................................................................................................................... 27 FIGURE 4-10: 2013 PEAK HOUR TRAFFIC FORECASTS WITHOUT DEVELOPMENT ........................... 33 FIGURE 4-11: 2019 PEAK HOUR TRAFFIC FORECASTS WITHOUT DEVELOPMENT ........................... 34 OPERATIONAL ANALYSIS .......................................................................................................................................... 35 TABLE 4-1: 2013 AND 2019 LEVELS OF SERVICE WITHOUT DEVELOPMENT ............................................. 36 FIGURE 4-12: 2013 LEVELS OF SERVICE WITHOUT DEVELOPMENT ............................................................ 37 FIGURE 4-13: 2019 LEVELS OF SERVICE WITHOUT DEVELOPMENT ............................................................ 38 Section 5 TRIP GENERATION, DISTRIBUTION AND ASSIGNMENT _________________________ 40 TRIP GENERATION ..................................................................................................................................................... 40 TABLE 5-1: TRIP GENERATION ........................................................................................................................ 41 PASS-BY TRIP REDUCTIONS .............................................................................................................................. 40 FIGURE 5-1: PASS-BY TRIP ASSIGNMENTS............................................................................................... 42 PRIMARY TRIPS SITE TRIPS.................................................................................................................................. 40 SITE TRIP DISTRIBUTION AND ASSIGNMENT .......................................................................................................... 40 SITE ACCESS ......................................................................................................................................................... 40 FIGURE 5-2: 2013 SITE TRIP DISTRIBUTION AND ASSIGNMENT .......................................................... 44 FIGURE 5-3: 2019 SITE TRIP DISTRIBUTION AND ASSIGNMENT .......................................................... 45



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Section 6 ANALYSIS OF 2013 FUTURE CONDITIONS WITH DEVELOPMENT ________________ 46 FUTURE TRAFFIC CONDITIONS WITH THE PROPOSED NEW USE ...................................................................... 46 FUTURE TRAFFIC FORECASTS ............................................................................................................................ 46 FIGURE 6-1: 2013 FUTURE PEAK HOUR TRAFFIC FORECASTS WITH DEVELOPMENT ...................... 47 FIGURE 6-2: 2013 FUTURE LANE USE AND TRAFFIC CONTROL WITH DEVELOPMENT .................. 48 OPERATIONAL ANALYSIS ................................................................................................................................... 46 TABLE 6-1: 2013 AND 2019 LEVELS OF SERVICE WITH DEVELOPMENT ............................................. 54 FIGURE 6-3: 2013 LEVELS OF SERVICE WITH DEVELOPMENT ............................................................... 55 Section 7 IMPROVEMENT ANALYSIS _______________________________________________________ 51 OVERVIEW ................................................................................................................................................................... 51 MEDIAN BREAK CLOSURE AT SPRING GARDEN APARTMENTS ............................................................................ 51 FIGURE 7-1: TRAFFIC ADJUSTMENTS FOR CLOSURE OF MEDIAN BREAK .................................................. 52 SITE TRIP ASSIGNMENTS ............................................................................................................................................ 51 FIGURE 7-2: MODIFIED 2013 SITE TRIP DISTRIBUTION AND ASSIGNMENT .............................................. 54 FIGURE 7-3: MODIFIED PASS-BY TRIP ASSIGNMENTS ................................................................................... 55 FIGURE 7-4: 2013 FUTURE PEAK HOUR TRAFFIC FORECASTS WITH IMPROVEMENTS ............................. 56 FIGURE 7-5: 2013 RECOMMENDED IMPROVEMENTS LANE USE AND TRAFFIC CONTROL ..................... 57 IMPROVEMENT ANALYSIS ........................................................................................................................................... 53 RIGHT TURN LANE WARRANT ANALYSIS ...................................................................................................... 53 CAPACITY ANALYSIS .......................................................................................................................................... 53 TABLE 7-1: 2013 LEVELS OF SERVICE WITH IMPROVEMENTS ................................................................ 58 FIGURE 7-6: 2013 LEVELS OF SERVICE WITH IMPROVEMENTS .............................................................. 59 RESULTS .............................................................................................................................................................. 53

Section 8 QUEUING ANALYSIS ____________________________________________________________ 61 OVERVIEW ................................................................................................................................................................... 61 TABLE 8-1: QUEUING ANALYSIS SUMMARY ................................................................................................... 62 Section 9 ANALYSIS OF 2019 FUTURE CONDITIONS WITH DEVELOPMENT ________________ 63 FUTURE TRAFFIC CONDITIONS WITH THE SITE DEVELOPMENT ......................................................................... 63 FIGURE 9-1: 2019 FUTURE PEAK HOUR TRAFFIC FORECASTS WITH DEVELOPMENT .............................. 64 FIGURE 9-2: 2019 FUTURE LANE USE AND TRAFFIC CONTROL WITH DEVELOPMENT .......................... 65 OPERATIONAL ANALYSIS .......................................................................................................................................... 63 TABLE 9-1: 2019 LEVELS OF SERVICE WITH IMPROVEMENTS ....................................................................... 66 FIGURE 9-3: 2019 LEVELS OF SERVICE WITH IMPROVEMENTS ..................................................................... 67 Section 10 ACCESS MANAGEMENT _________________________________________________________ 68



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Section 11 ANALYSIS OF FUTURE CONDITIONS WITH ALTERNATIVE DEVELOPMENT OPTIONS ________________________________________________________________________ 70 OVERVIEW ................................................................................................................................................................... 70 TRIP GENERATION ..................................................................................................................................................... 70 TABLE 11-1: ALTERNATIVE TRIP GENERATION ANALYSIS ........................................................................... 71 FIGURE 11-1: PASS-BY TRIP ASSIGNMENTS (RETAIL ALTERNATIVE) .......................................................... 72 FIGURE 11-2: 2013 SITE TRIP DISTRIBUTION AND ASSIGNMENT (RETAIL ALTERNATIVE) ..................... 73 FIGURE 11-3: 2013 SITE TRIP DISTRIBUTION AND ASSIGNMENT (MOVIE THEATER ALTERNATIVE) ..... 74 FUTURE TRAFFIC CONDITIONS WITH THE ALTERNATIVE DEVELOPMENT ........................................................ 70 FIGURE 11-4: 2013 FUTURE PEAK HOUR TRAFFIC FORECASTS WITH DEVELOPMENT (RETAIL ALTERNATIVE) ...................................................................................................................................... 75 FIGURE 11-5: 2013 FUTURE PEAK HOUR TRAFFIC FORECASTS WITH DEVELOPMENT (MOVIE THEATER ALTERNATIVE) ..................................................................................................................... 76 OPERATIONAL ANALYSIS .......................................................................................................................................... 70 TABLE 11-2: 2013 LEVELS OF SERVICE WITH ALTERNATIVE DEVELOPMENTS ........................................... 78 FIGURE 11-6 2013 LEVELS OF SERVICE WITH ALTERNATIVE DEVELOPMENTS (RETAIL ALTERNATIVE) ...................................................................................................................................... 79 FIGURE 11-7 2013 LEVELS OF SERVICE WITH ALTERNATIVE DEVELOPMENTS (MOVIE THEATER ALTERNATIVE) ..................................................................................................................... 80 Section 12 CONCLUSIONS AND RECOMMENDATIONS _____________________________________ 81 PRINCIPAL FINDINGS ................................................................................................................................................. 81 RECOMMENDATIONS ................................................................................................................................................. 82



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LIST OF FIGURES FIGURE TITLE 1-1 LIMITS OF STUDY AREA ................................................................................................................................ 3 2-1 SITE LOCATION MAP .................................................................................................................................... 6 2-2 EXISTING ZONING ........................................................................................................................................ 7 2-3 PROPOSED PLAN REDUCTION .................................................................................................................... 8 2-4 EXISTING LANE USE AND TRAFFIC CONTROL ....................................................................................... 11 2-5 COMPREHENSIVE PLAN RECOMMENDATIONS (TRANSPORTATION – NORTH AREA) ...................... 14 2-6 COMPREHENSIVE PLAN RECOMMENDATIONS (TRANSPORTATION – SOUTH AREA) ....................... 15 3-1 EXISTING PEAK HOUR TRAFFIC VOLUMES .............................................................................................. 17 3-2 EXISTING PEAK HOUR PEDESTRIAN VOLUMES ....................................................................................... 18 3-3 EXISTING LEVELS OF SERVICE ..................................................................................................................... 21 4-1 2013 REGIONAL GROWTH FOR BUILD OUT .......................................................................................... 23 4-2 2019 REGIONAL GROWTH FOR BUILD OUT .......................................................................................... 24 4-3 LOCATION OF PIPELINE DEVELOPMENTS ................................................................................................. 25 4-4 SUMMARY OF THE BRAC PREFERRED ALTERNATIVE: NEW AND RENOVATED PIPELINE

DEVELOPMENTS ........................................................................................................................................... 26 4-5 LOCATION OF THE BRAC PREFERRED ALTERNATIVE: NEW AND RENOVATED PIPELINE

DEVELOPMENTS ........................................................................................................................................... 27 4-6 BRAC TRIP ASSIGNMENTS ......................................................................................................................... 29 4-7 2019 PLANNED FUTURE LANE USE AND TRAFFIC CONTROL WITHOUT DEVELOPMENT ............... 30 4-8 MOUNT VERNON GATEWAY TRIP ASSIGNMENTS ................................................................................. 31 4-9 2019 Traffic REDISTRIBUTIONS FOR RIGHT-IN, RIGHT-OUT BUCKMAN ROAD .............................. 32 4-10 2013 PEAK HOUR TRAFFIC FORECASTS WITHOUT DEVELOPMENT .................................................... 33 4-11 2019 PEAK HOUR TRAFFIC FORECASTS WITHOUT DEVELOPMENT .................................................... 34 4-12 2013 LEVELS OF SERVICE WITHOUT DEVELOPMENT .............................................................................. 38 4-13 2019 LEVELS OF SERVICE WITHOUT DEVELOPMENT .............................................................................. 39 5-1 PASS-BY TRIP ASSIGNMENTS ...................................................................................................................... 42 5-2 2013 SITE TRIP DISTRIBUTION AND ASSIGNMENT ................................................................................. 44 5-3 2019 SITE TRIP DISTRIBUTION AND ASSIGNMENT ................................................................................. 45 6-1 2013 FUTURE PEAK HOUR TRAFFIC FORECASTS WITH DEVELOPMENT ............................................. 47 6-2 2013 PLANNED FUTURE LANE USE AND TRAFFIC CONTROL WITH DEVELOPMENT ....................... 48 6-3 2013 LEVELS OF SERVICE WITH DEVELOPMENT ...................................................................................... 50 7-1 TRAFFIC ADJUSTMENTS FOR CLOSURE OF MEDIAN BREAK .................................................................. 52 7-2 MODIFIED 2013 SITE TRIP DISTRIBUTION AND ASSIGNMENT .............................................................. 55 7-3 Modified Pass-BY TRIP ASSIGNMENTS ..................................................................................................... 56 7-4 2013 FUTURE PEAK HOUR TRAFFIC FORECASTS WITH IMPROVEMENTS ............................................ 57 7-5 2013 RECOMMENDED IMPROVEMENTS LANE USE AND TRAFFIC CONTROL ..................................... 58 7-6 2013 LEVELS OF SERVICE WITH IMPROVEMENTS ..................................................................................... 59



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LIST OF FIGURES (CONTINUED) 9-1 2019 FUTURE PEAK HOUR TRAFFIC FORECASTS WITH DEVELOPMENT ............................................. 64 9-2 2019 PLANNED FUTURE LANE USE AND TRAFFIC CONTROL WITH DEVELOPMENT ....................... 65 9-3 2019 LEVELS OF SERVICE WITH DEVELOPMENT ...................................................................................... 67 11-1 PASS-BY TRIP ASSIGNMENTS (RETAIL ALTERNATIVE) ............................................................................ 73 11-2 2013 SITE TRIP DISTRIBUTION AND ASSIGNMENT (RETAIL ALTERNATIVE) ....................................... 74 11-3 2013 SITE TRIP DISTRIBUTION AND ASSIGNMENT (MOVIE THEATER ALTERNATIVE) ...................... 75 11-4 2013 FUTURE PEAK HOUR TRAFFIC FORECASTS WITH DEVELOPMENT (RETAIL ALTERNATIVE) .... 76 11-5 2013 FUTURE PEAK HOUR TRAFFIC FORECASTS WITH DEVELOPMENT (MOVIE THEATER ALTERNATIVE) .............................................................................................................. 77 11-6 2013 LEVELS OF SERVICE WITH DEVELOPMENT (RETAIL ALTERNATIVE) ............................................. 79 11-7 2013 LEVELS OF SERVICE WITH DEVELOPMENT (MOVIE THEATER ALTERNATIVE) ............................ 80 LIST OF TABLES TABLE TITLE 1-1 INFLUENCE AREA ........................................................................................................................................... 4 3-1 EXISTING LEVELS OF SERVICE ..................................................................................................................... 20 4-1 LEVELS OF SERVICE WITHOUT DEVELOPMENT ........................................................................................ 37 5-1 TRIP GENERATION ...................................................................................................................................... 41 6-1 2013 LEVELS OF SERVICE WITH DEVELOPMENT ...................................................................................... 49 7-1 2013 LEVELS OF SERVICE WITH IMPROVEMENTS ..................................................................................... 59 8-1 QUEUING ANALYSIS SUMMARY ................................................................................................................. 62 9-1 2019 LEVELS OF SERVICE WITH IMPROVEMENTS ..................................................................................... 66 11-1 ALTERNATIVE TRIP GENERATION ANALYSIS ........................................................................................... 72 11-2 2013 LEVELS OF SERVICE WITH ALTERNATIVE DEVELOPMENTS ........................................................... 78



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LIST OF APPENDICES APPENDIX TITLE A Scoping Agreement B Descriptions of Levels of Service C Statement of Justification D Conceptual/Final Development Plan E Comprehensive Plan Language - Land Unit D F VDOT Route 1 Location Study Plans G Fairfax Connector and Metrobus Route Schedules H Existing Peak Hour Traffic Counts and Pedestrian Counts I Existing Capacity Analyses J Excerpts from the Final Environmental Impact Statement for Implementation of 2005 Base Realignment and Closure (BRAC) and Trip Assignments K Mount Vernon Gateway Proffers and Final Development Plan L Mount Vernon Gateway Trip Generation Summary and Trip Assignments M 2013 Synchro Capacity Analysis Worksheets Without Development N 2019 Synchro Capacity Analysis Worksheets Without Development O 2013 Synchro Capacity Analysis Worksheets With Development P Turn Lane Warrant Analyses Q 2013 Synchro Capacity Analysis Worksheets With Improvements R Synchro Queuing Analysis Worksheets S 2019 Synchro Capacity Analysis Worksheets With Improvements T VDOT Entrance Standards for Principal Arterials U 2013 Synchro Capacity Analysis Worksheets With Alternative Development



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EXECUTIVE SUMMARY

PURPOSE OF REPORT & STUDY OBJECTIVES In 2006, the General Assembly approved legislation to enhance the coordination of land use and transportation planning in the Commonwealth. This traffic impact study was prepared in accordance with this legislation (Chapter 155, 24VAC 30-155). Specifically, the purpose of this study is to assess the impacts of a proposed new retail warehouse in Fairfax County on the surrounding and adjacent transportation network and to identify potential mitigation measures, which may be necessary to off-set any impacts associated with the new use. SITE LOCATION AND STUDY AREA The approximate 12-acre site is located west of Richmond Highway (Route 1), and north of Ladson Lane in Fairfax County, Virginia. The site is identified on the Fairfax County GIS as Tax Map 101-2 ((6)) A and as 7940 Richmond Highway. The study area, as reviewed and agreed to with VDOT and County staff, is generally bounded by Sherwood Hall Lane on the north, Route 1 on the east and Buckman Road on the south. The following intersections were included in the study area:

1. Richmond Highway (Route 1)/Sherwood

Hall Lane/Wal-Mart Driveway 2. Richmond Highway (Route 1)/Site Right-

in/Right-out Driveway 3. Richmond Highway (Route 1)/Ladson Lane 4. Richmond Highway (Route 1)/Buckman

Road/Mount Vernon Highway 5. Ladson Lane/Site Entrance 6. Ladson Lane/Audubon Avenue 7. Richmond Highway (Route 1)/Spring

Garden Apartments Entrance 8. Subject property interparcel connection

to/from Wal-Mart

DESCRIPTION OF PROPOSED DEVELOPMENT Overview. The Applicant, Costco Wholesale, proposes to raze the former Mount Vernon Multiplex cinema and construct a 143,416 gross square foot (GSF) retail warehouse for members only in accordance with Fairfax County’s “big box” ordinance. To that end the Applicant will file a Special Exception (SE) application with the County. The property is currently developed with a 53,073 GSF building (now vacant) that previously operated as the 10-screen multiplex with a seating capacity of approximately 3,000. Vehicular access to the property will continue to be provided via an existing right-in/right-out entrance on Richmond Highway and a relocated full movement entrance/exit on Ladson Lane. Additional interparcel access is afforded to/from the Wal-Mart located to the north of the subject property. Conformance with the Fairfax County Comprehensive Plan. The Applicant intends to develop the property in a manner generally compatible with, and respectful of, adjacent and nearby land uses, and in accord with the recommendations of the Fairfax County Comprehensive Plan. PRINCIPAL FINDINGS The principal findings of this transportation impact study are as follows: 1. The results of the existing analyses indicate

that the Richmond Highway/Ladson Lane signalized intersection currently operates at an overall acceptable level of service during all peak periods. The Richmond Highway/Sherwood Hall Lane/Wal-Mart Driveway and Richmond Highway/Mount



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Vernon Highway/Buckman Road intersections operate near capacity. All of the approaches at the stop controlled intersections currently operate at acceptable levels of service.

2. Background traffic from two (2) pipeline developments (BRAC and Mount Vernon Gateway) would add new trips to the road network. BRAC would generate regional trips and Mount Vernon Gateway would generate local trips in the study area.

3. The results for the background capacity

analyses (without the proposed uses) for the year 2013 indicate overall consistent levels of service when compared to existing conditions with minor increases in delay as a result of regional traffic growth and pipeline developments.

4. Under 2019 conditions without the

development, the individual lane groups at each of the three (3) signalized intersections on Richmond Highway would continue to operate at, or near capacity, similar to existing conditions but with higher delays.

5. Costco Wholesale proposes to raze an

existing closed theatre and construct a 143,416 GSF retail discount store. This new retail store is expected to add a total of 456 new PM peak hour trips and 737 new peak hour trips on Saturday, when fully constructed and occupied. This proposal would add 4,496 new daily (24-hour) trips on weekdays.

6. The results for the total future analyses (with the proposed uses) indicate similar delays to those identified under background conditions with slight increases. The vehicle queue at the northbound left-turn lane on Richmond Highway at Ladson Lane would exceed the available turn lane storage.

7. Intersection lane use and signal phasing improvements at all three (3) signalized intersections on Richmond Highway would improve levels of service and reduce vehicle queues. The vehicle queue at the northbound left-turn lane on Richmond Highway at Ladson Lane would reduce with signal improvements but continue to exceed the available turn lane storage.

8. A traffic control sign indicating “Right-turns yield to U-turning vehicles” should be installed at the eastbound right-turn lane on Ladson Lane at the Richmond Highway/Ladson Lane intersection to mitigate the existing “U-Turn” conflict with the eastbound overlap right-turn movement from Ladson Lane.

9. The results for the 2019 future analyses

with the development indicate similar delays to those identified under 2019 future analysis without development with the exception of Richmond Highway/Mount Vernon Highway/Buckman Road intersection that would operate at overall theoretical capacity during Saturday peak hour.

10. The 2013 future analysis with by-right retail alternative indicates that the signalized intersections of Richmond Highway/Sherwood Hall Lane/Wal-Mart Driveway and Richmond Highway/Mount Vernon Highway/Buckman Road would operate at overall levels of service consistent with the 2013 future analysis



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with proposed development except with higher delays during the PM and Saturday peak hours.

11. Under 2013 by-right retail alternative, the signalized intersection of Richmond Highway/Ladson Lane and certain critical movements at the STOP controlled intersection of Ladson Lane and Site Entrance would however operate at theoretical capacity during the PM and Saturday peak hours.

12. The 2013 future analysis with the existing

movie theater as operational indicates that each of the study intersections would operate at levels of service consistent with the 2013 future analysis with proposed development except with lower delays during the PM and Saturday peak hours.

13. The alternative analysis indicates that the

proposed development is less intensive use than a by-right retail use. Additionally, the proposed new Costco development would not have a significantly higher impact than an operational movie theater located on the subject site.

RECOMMENDATIONS The following improvements should be completed by the Applicant to offset the impact of the proposed new Costco Wholesale: 1. Modification of the signal timing splits at the Richmond Highway/Ladson Lane intersection to provide additional green time for heavier turn movements. Modification of the signal timing splits at the Richmond Highway/Sherwood Hall Lane/Wal-Mart Driveway intersection. Modification of the signal timing splits at the Richmond Highway/Buckman Road/Mount Vernon Highway intersection.

2. Construction of an exclusive southbound right-turn lane at the Richmond Highway/Ladson Lane intersection. 3. Construction of an exclusive westbound right-turn lane at the Ladson Lane/Site Entrance intersection. 4. Closure of the existing median break at the intersection of Richmond Highway and entrance to the Spring Garden Apartments.

5. Extension of the existing northbound left-

turn lane at the intersection of Richmond Highway/Sherwood Hall Lane/Wal-Mart Driveway intersection to approximately 625 feet.



SECTION 1 INTRODUCTION STUDY OBJECTIVES This report presents the results of a traffic impact study (as required by 24 VAC 30-155) in support of a Special Exception application to permit an approximate 143,416 gross square foot (GSF) retail sales establishment-large in accordance with the provisions of Article 9-533 of the Fairfax County Zoning Ordinance. The proposal seeks to raze the existing Mount Vernon Multiplex, no longer in operation, with a “members only” Costco Wholesale warehouse in Fairfax County, Virginia. The proposed Costco Wholesale warehouse would not include a gas station. This study was conducted in accordance with both Fairfax County’s “Recommended Guidelines for Traffic Impact Studies” and the Virginia Department of Transportation (VDOT) Traffic Impact Analysis Regulations Administrative Guidelines 24 VAC 30-155. The study area was determined in consultation with VDOT and County staff based on a review of key study intersections and roadways that potentially would be affected by implementation of the proposed development plan and the number of new trips expected to be generated by the proposed new use. The study includes a number of adjacent on and off-site intersections. The approved VDOT scoping form is included as Appendix A. Tasks undertaken in this study included the following: 1. A review of the design concept plans

prepared by Bohler Engineering, P.C., and other background materials.

2. Meetings and discussions with the VDOT and Fairfax County Department of Transportation (FCDOT) regarding the proposed traffic analysis scope, trip generation, procedures, and other study parameters.

3. A field reconnaissance of existing roadway and intersection geometrics, traffic controls, traffic signal phasings/timings, and speed limits.

4. Turning movement counts at major intersections and site entrances during the weekday PM peak period and Saturday mid-day peak period.

5. Analysis of existing levels of service at seven (7) study intersections and driveways. An eighth internal intersection was included for information use only but not analyzed.

6. Calculation of the number of weekday PM

and Saturday mid-day peak hour trips that would be generated by pipeline developments in proximity to the proposed new use.

7. Forecasted background traffic volumes for

the year 2013 and 2019 without the proposed new use.

8. Estimation of the number of weekday PM

peak hour trips and Saturday mid-day peak trips that would be generated by the planned Costco Wholesale warehouse as well as other by-right on-site uses.

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9. Projection of total future traffic forecasts for the study years 2013 and 2019 with the proposed new Costco.

10. Calculation of year 2013 and 2019

background and total future levels of service at the study intersections based on future traffic forecasts and existing/planned intersection geometries.

11. Identification of traffic improvements/

enhancements necessary to accommodate future forecasts as a result of the new Costco.

Sources of data for this analysis included traffic counts conducted by Wells + Associates; conceptual design plans provided by Bohler Engineering, P.C.; McGuireWoods; the Institute of Transportation Engineers (ITE); Virginia Department of Transportation (VDOT); Fairfax County; and Costco Wholesale. STUDY AREA This study was conducted in accordance with the parameters set forth in the April 2010 scoping agreement document included as Appendix A and agreed to by VDOT, the County, the Applicant and his representatives. The study area (see Figure 1-1) was selected based on those intersections potentially affected by the proposed new Costco Wholesale warehouse. For purposes of this analysis, the following existing intersections were included in the study area:

1. Richmond Highway (Route 1)/Sherwood Hall Lane (Route 626)

2. Route 1/Site entrance (Right-in/Right-out) 3. Route 1/Ladson Lane (Route 921) 4. Route 1/Buckman Road north(Route 836) 5. Ladson Lane/Site Entrance 6. Ladson Lane/Audubon Avenue 7. Route 1/Spring Garden Apartments

Entrance 8. Site/Walmart Interparcel Connection The total volume of projected peak hour trips through each intersection listed above is summarized on Table 1-1. Based on the trip distributions developed and approved for this analysis by VDOT, the County and the Applicant, the volume and percentage of site trips through each intersection is also included in Table 1-1. As shown, with the exception of the Ladson Lane and Wal-Mart Entrance locations on Route 1, site-generated trips at each of the study intersections accounts for less than 10% of the peak hour volumes in the future. This report, as required by VDOT and FCDOT, presents an analysis of existing transportation conditions in the site vicinity, an analysis of year 2013 no-build conditions, and an analysis of 2013 traffic conditions after completion and build-out of the proposed new uses. Additionally, an analysis of build out plus six year (2019) conditions was also completed. Additionally, for comparison purposes, an analysis of future conditions at key study intersections reflective of certain alternative by-right uses was undertaken and the results presented herein.

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Source: Google

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Table 1-1 Influence Area

Intersection 2013 Total Future

Forecasts Site-Generated Forecasts % Site Trips

AM Peak PM Peak AM Peak PM Peak AM Peak PM Peak Richmond Highway/Sherwood Hall Lane 6,306 6,180 231 370 3.7% 6.0%

Route 1/Site Entrance 5,993 5,718 251 405 4.2% 7.1%

Route 1/Ladson Lane 5,795 5,539 160 261 2.8% 4.7%

Route 1/Buckman Road North 6,129 6,042 317 514 5.2% 8.5%

Ladson Lane/Site Entrance 5,635 5,285 232 376 4.1% 7.1%

Ladson Lane/ Audubon Avenue 850 1,041 278 450 32.7% 43.2%

Route 1/Spring Garden Apartment Entrance 476 395 8 16 1.7% 4.1%

Site/Walmart Interparcel Connection 277 426 178 287 64.3% 67.4%

STUDY METHODOLOGY Synchro software (version 7) was used to evaluate levels of service at the study intersections during the PM and Saturday peak hours. As discussed with FCDOT and VDOT, an analysis of the AM peak hour was not required because the proposed Costco Wholesale warehouse would not be open to the public between the hours of 6:00 and 9:00 AM. Synchro is a macroscopic model used for optimizing traffic signal timing and performing capacity analyses. The software can model existing traffic signal timings or optimize splits, offsets, and cycle lengths for individual intersections, an arterial, or a complete network. Synchro allows the user to evaluate the effects of changing intersection geometrics, traffic demands, traffic control, and/or traffic signal settings as well as optimize traffic signal timings.

The levels of service reported for the signalized and unsignalized intersections analyzed herein were taken from the Highway Capacity Manual 2000 (HCM) reports generated by Synchro version 7. Level of service descriptions are included in Appendix B.

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SECTION 2 BACKGROUND INFORMATION SITE LOCATION/DESCRIPTION Overview. The approximate 12-acre subject site is located west of Richmond Highway (Route 1), and north of Ladson Lane in Fairfax County, Virginia, as shown on Figure 2-1. The site is identified on the Fairfax County GIS as Tax Map 101-2 ((6)) A and as 7940 Richmond Highway. The property is currently developed with a 53,073 gross square foot (GSF) vacant building that previously operated as the 10-screen Mount Vernon Multiplex with a seating capacity of approximately 3,000. The Applicant, Costco Wholesale, proposes to raze the former cinema and construct a 143,416 GSF retail warehouse for members only in accordance with Fairfax County’s “big box” ordinance. To that end the Applicant will file a Special Exception (SE) application with the County. A copy of the Applicant’s Statement of Justification is provided in Appendix C. Terrain. The terrain proximate to and surrounding the site is generally classified as “level”. Existing Zoning. The site is currently zoned C-8 (Highway Commercial). The C-8 zoning district was established as follows:

“…to provide locations on heavily traveled collector and arterial highways for uses which (a) are oriented to the automobile, or (b) uses which may require large land areas and good access, and (c) do not depend upon adjoining uses for reasons of comparison shopping or pedestrian trade.”

The maximum development permitted in the C-8 district is limited to a 0.5 floor area ratio (FAR), or in this case 261,360 GSF. With approval of a Special Exception, development up to a 0.7 FAR may be permitted. The Applicant is proposing development of the new Costco at a FAR of 0.27. Nearby Uses. The parcel to the north of the subject site is also zoned C-8 and developed with a Wal-Mart. The parcel to the east is zoned R-MHP (Residential District, Mobil Home Park). The parcels to the south are zoned C-8 and R-12 (Residential at 12 dwelling units per acre). Immediately to the east across Richmond Highway are parcels zoned C-8, C-2 (Limited Office) and R-3 (Residential at three dwelling units per acre). The subject site and adjacent properties along Richmond Highway are also located within a Highway Corridor Overlay (H-C) district. Figure 2-2 depicts the existing zoning associated with the subject site and neighboring properties, as reflected on the Fairfax County zoning map. Site Access. Vehicular access to the property will be provided via an existing right-in/right-out entrance on Richmond Highway and a relocated full movement entrance/exit on Ladson Lane. Additional interparcel access is afforded to/from the Wal-Mart located to the north of the subject property. A reduction of the proposed plan is provided on Figure 2-3. A full-size copy of the overall layout is included as Appendix D.

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COMPREHENSIVE PLAN – LAND USE RECOMMENDATIONS The subject property is located within the Richmond Highway Corridor Area of the Mount Vernon Planning District of Fairfax County. Land use recommendations for the property are governed by the text associated with the Hybla Valley/Gum Springs Community Business Center. The property is located within Land Unit D, Sub-unit D-4. Sub-unit D-4 consists of the subject site and the adjacent Wal-Mart property. The Plan recommends development of the site with retail uses up to a 0.50 FAR including the existing Wal-Mart (also located within D-4). The Comprehensive Plan text for Land Unit D is included as Appendix E. In addition to the above corridor objectives and goals, the Plan also provides specific guidance on development within the five Community Business centers. The Richmond Highway corridor is envisioned to contain five Community Business Centers (CBC’s) intended to provide community-serving retail, residential and mixed uses. From north to south the CBC’s are identified as the following: • North Gateway • Penn Daw • Beacon/Groveton • Hybla Valley/Gum Springs • Woodlawn

The proposed Costco Wholesale warehouse would be located within the Hybla Valley/Gum Springs CBC.

ROADWAY NETWORK Existing Roadway Network. Regional access to the proposed Costco Wholesale would be provided from Richmond Highway (Route 1). Local access is provided from Ladson Lane (Route 921), Sherwood Hall Lane (Route 626), Buckman Road (Route 836), and Mount Vernon Highway (Route 235). The existing lane use and traffic controls in the vicinity are shown on Figure 2-4. Richmond Highway (Route 1). Richmond Highway is major north-south transportation route in Fairfax County that extends from the City of Alexandria in the north to Prince William County to the south. Richmond Highway is a six-lane, median-divided, highway north of Ladson Lane transitioning to a two-lane, highway south of Ladson lane. The roadway is classified as a “Principal Arterial” under the Fairfax County Comprehensive Plan or an “Urban Other Principal arterial” as classified by VDOT’s Virginia Highway Functional Classification. The posted speed limit is 45 miles per hour (mph) and it carries approximately 60,000 average daily traffic (ADT) in the vicinity of the proposed site. Sherwood Hall Lane (Route 626). Sherwood Hall Lane is a two-lane, undivided, east-west “Minor Arterial (Type B)” roadway as classified under the Fairfax County Comprehensive Plan or an “Urban Minor Arterial” as classified by VDOT’s Virginia Highway Functional Classification. Sherwood Hall Lane directly connects to an assortment of residential neighborhoods to the east of Route 1 and is the fourth approach at the signalized Route 1/Wal-Mart’s main entrance intersection. The posted speed limit is 35 mph and it carries approximately 22,000 ADT in the vicinity of the proposed site.

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Ladson Lane (Route 921). Ladson Lane is an approximate 900 foot (0.17 mile) roadway segment that directly fronts the subject property on its southwest side. It provides a connection from Richmond Highway (Route 1) to Audubon Road, which serves the Audubon Mobile Home (MH) Park. Ladson Lane is a two-lane (approximately 40 foot-wide) collector road with on-street parking permitted along both sides. The posted speed limit is 25 mph and the roadway carries approximately 6,000 ADT. Currently, an existing driveway to the subject property is located on Ladson Lane approximately 200 feet west of Route 1. This proposal would relocate this driveway approximately 620 feet west of Route 1. Mount Vernon Highway (Route 235). Mount Vernon Highway is a two-lane undivided, north-south “Minor Arterial (Type B)” as classified by the Fairfax County Comprehensive Plan or an “Urban Minor Arterial” as classified by VDOT’s Virginia Highway Functional Classification. Mount Vernon Highway connects an assortment of residential neighborhoods to the south and east of the site with Route 1 and approaches Route 1 at a traffic signal directly opposite Buckman Road north (Route 836). The posted speed limit is 35 mph and it carries approximately 13,000 average daily vehicles (ADT) in the vicinity of the subject site. Buckman Road (Route 836). Buckman Road is a two-lane undivided, north-south collector roadway with on-street parking permitted along both sides. It is an approximately 1.3 mile roadway segment that begins and ends on Route 1 and directly connects to an assortment of residential neighborhoods to the west. The posted speed limit is 35 mph and it carries approximately 13,000 ADT from Richmond Highway north to Russell Road and approximately 4,600 ADT from Russell Road to Richmond Highway south.

Audubon Avenue. Audubon Avenue is a private road with a post speed limit of 15 mph that directly serves the Audubon Mobile Home Park. This roadway intersects Ladson Lane (Route 921) at a “T” intersection. Future Roadway Network. The subject property is located within the Mount Vernon Planning District, Hybla Valley/Gum Springs Community Business Center (CBC). The Hybla Valley/Gum Spring CBC contains stable residential neighborhoods, as well as two of the largest retail centers in the District. Specific land use and transportation recommendations for the property are addressed within the recommendations for the Richmond Highway Corridor Area. Richmond Highway Corridor Area. As defined by the Plan, the Richmond Highway Corridor Area extends south from the Capital Beltway (I-495) to Fort Belvoir for a distance of 1,000 feet east and west of the existing centerline. The primary goal of the Plan for the Richmond Highway Corridor is to “promote revitalization and redevelopment while maintaining an acceptable land use and transportation balance.” Richmond Highway serves a dual purpose as a multi-functional, north-south transportation route, serving both commuter traffic from the south and local traffic to/from the many commercial and residential developments located to the east and west along this critical link. Richmond Highway currently varies from four to six lanes along its length and carries in excess of 60,000 vehicles per day. Meeting the transportation needs and mitigating increasing levels of traffic congestion along this critical corridor were major concerns in the development of the Plan.

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To that end, the Plan includes the following overall corridor-wide objectives intended to guide transportation decisions in the corridor: • Provide improved traffic circulation and

traffic safety during both peak and non-peak hours.

• Maximize the efficiency of existing highway facilities to move people and goods.

• Promote the increased use of ridesharing and public transportation to reduce reliance on automobile.

• Minimize the impact of highway widening, new roadway alignments, and new development projects on adjacent residential communities and the ecology of the district.

The Plan objectives further state that service drive construction should not generally be required where inter-parcel access can be provided between adjacent developments. Existing service drives should be replaced wherever possible. Highway right-of-way dedication or reservation will be required where necessary. Planned/Programmed Improvements. Transportation recommendations for the application area are depicted on Figure 2-5 and Figure 2-6 from the Comprehensive Plan. These improvements include the following: • Improve/upgrade Richmond Highway

(Route 1) to be a six-lane roadway. Richmond Highway is currently a six-lane divided facility north of Ladson Lane and a two-lane divided facility south of Ladson Lane.

• Construct/implement a rail transit or bus rapid transit (BRT) along Richmond Highway (Route 1).

• Improve/upgrade Buckman Road (Route 836). The Comprehensive Plan designates Buckman Road to be a two-lane roadway which is the current function of the

roadway today. • Improve/upgrade Mount Vernon Highway

(Route 235). The Comprehensive Plan designates Mount Vernon Highway to be a two-lane roadway which is the current function of the roadway today.

Route 1 Location Study. VDOT initiated a comprehensive study of the Route 1 corridor in response to increasing levels of congestion along Richmond Highway (Route 1). The Route 1 Location Study was intended to build on previous corridor studies conducted between 1994 and 1997, and provide a blueprint for future improvement of this critical highway. The entire project consists of a 27.3-mile corridor in Prince William and Fairfax Counties. Study A extends from Stafford County north through Prince William County. Study B comprises the 4.3-mile section from the Occoquan River to Telegraph Road. Study C extends 10.8 miles from Telegraph Road to I-495. The subject properties are located within the limits of Study C. There are no current plans to proceed with any of the design alternatives however for informational purposes, area roadway alternatives are included as part of Appendix F. TRANSIT FACILITIES The subject area is served by the Fairfax Connector and the Metrobus bus lines. Fairfax Connector. The subject site is served by four (4) Fairfax Connector buses within the vicinity of the site. Two (2) bus lines (Route 151 and Route 152) are accessible directly on Richmond Highway (Route 1) fronting the site and two (2) bus lines (Route 161 and Route 162) are accessible approximately 1/3 mile away at the Sherwood Hall Lane/Fordson Road intersection. Each of the buses described above are “Richmond Highway Circulator” bus lines

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that provide service from the Huntington Metrorail station to points along Richmond Highway as far south as the Mount Vernon Hospital and Mount Vernon Estate. WMATA Metrobus. The subject site is also directly served by the Metrobus Richmond Highway Express (REX) line on Richmond Highway (Route 1). This bus line provides express service along Richmond Highway connecting the King Street, Eisenhower Avenue, and Huntington Metrorail stations from the north with Jackson Loop (north) and Gunston Road (Fort Belvoir) to the south. Fairfax Connector and Metrobus route schedules are provided in Appendix G.

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SECTION 3 ANALYSIS OF EXISTING CONDITIONS TRAFFIC VOLUMES Wells + Associates conducted traffic and pedestrian counts at the following intersections in accordance with Fairfax County and VDOT guidelines: 1. Richmond Highway (Route 1)/Sherwood

Hall Lane 2. Richmond Highway (Route 1)/Site Right-

in/Right-out driveway 3. Richmond Highway (Route 1)/Ladson Lane 4. Richmond Highway (Route 1)/Buckman

Road/Mount Vernon Highway 5. Ladson Lane/Site Entrance 6. Ladson Lane/Audubon Avenue 7. Richmond Highway (Route 1)/Spring

Garden Apartments Entrance 8. Subject property interparcel connection

to/from Wal-Mart Weekday peak period vehicular turning movement and pedestrian counts were conducted on Wednesday, April 28, 2010 from 3:30 PM to 7:30 PM. Saturday peak period vehicular turning movement and pedestrian counts were conducted on Saturday, May 1, 2010 from 10:00 AM to 3:00 PM. The weekday and Saturday traffic and pedestrian volumes are shown on Figures 3-1 and 3-2, respectively. Traffic and pedestrian count worksheets are contained in Appendix H. All of the counts were recorded in 15-minute increments. For purposes of this traffic analysis, the peak hour of each individual intersection was utilized. The traffic counts were then balanced between intersections in order to account for seasonal and time-of-day variations in the count data. Where appropriate, some minor imbalance was

allowed between study intersections to account for mid-block driveways and parking lot entrances such as along Richmond Highway (Route 1). Daily traffic volumes on roadway links within the study area were estimated by applying the appropriate K-factors provided in VDOT’s traffic count data sheets to the baseline peak hour traffic volumes. The existing daily traffic estimates (vpd) are provided on Figure 3-1. It should be noted significant number of vehicles were observed making U-turn maneuvers on Richmond Highway (Route 1). The U-turning volumes were the highest on northbound Richmond Highway at Ladson Lane and on southbound Richmond Highway at Mount Vernon Memorial Highway. The U-turns occur to allow vehicles to access right-in/right-out driveways along Route 1. An overlapping right turn phase is currently provided for eastbound Ladson Lane at Route 1. These right turns conflict with the high volume of U-turns on Richmond Highway, creating a potentially hazardous situation. A “Yield to U-turns on Richmond Highway” traffic sign placed at the right-turn lane on Ladson Lane should be considered as one way to resolve this conflict. OPERATIONAL ANALYSIS Existing peak hour levels of service (LOS) were calculated at key study intersections and driveways based on the existing lane use and traffic control shown on Figure 2-4, the existing traffic volumes shown on Figure 3-1, the existing pedestrian volumes shown on Figure 3-2, and the Highway Capacity Manual

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methodology as reported by Synchro. Existing traffic signal timings and Synchro/SimTraffic files were obtained from VDOT. The VDOT Synchro files were modified to include site driveways as well as to address minor discrepancies with field-verified lane use, storage lengths and signal timings. The results of the intersection analyses are summarized in Table 3-1 and Figure 3-3. Capacity analysis worksheets are included in Appendix I. The results of the existing intersection capacity analyses indicate the following: 1. The Richmond Highway (Route

1)/Sherwood Hall Lane/Wal-Mart Driveway intersection operates near capacity at LOS “E” during both peak periods.

2. The Richmond Highway (Route 1)/Ladson Lane signalized intersection operates at overall LOS “B” or better during the weekday PM and Saturday mid-day peak periods.

3. The Richmond Highway (Route 1)/Mount

Vernon Highway/Buckman Road intersection operates near capacity at LOS “E” during the Saturday peak period.

4. All of the STOP controlled traffic movements operate at an acceptable LOS “D” or better.

5. All three (3) signalized study intersections

contain lane groups operating near capacity (LOS “E”). Richmond Highway (Route 1)/Sherwood Hall Lane/Wal-Mart driveway and Richmond Highway (Route 1)/Mount Vernon Highway/Buckman Road intersections contain lane groups operating at capacity (LOS “F”).

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Table 3-1Costco Wholesale - Alexandria/Mount VernonExisting Levels of Service (1) (2) (3)

Intersection CriticalIntersection Control Movement Weekday PM Saturday

(1) Richmond Highway (Route 1)/ Signal EBL E (77.6) F (87.6)Sherwood Hall Lane/ EBT E (72.0) E (70.3)Wal-Mart Driveway EBR E (75.6) E (68.9)

WBL F (94.6) F (99.4)WBLT F (93.1) F (100.3)WBR D (46.3) E (63.0)NBL F (115.8) F (89.3)

NBTR E (68.7) E (56.3)SBL E (74.4) F (105.3)SBT D (47.8) D (37.4)SBR C (23.7) C (22.0)

Overall E (65.4) E (57.2)

(2) Richmond Highway (Route 1)/ STOP EBR B [11.1] B [10.5]Site Driveway

(3) Richmond Highway (Route 1)/ STOP WBLR B [13.2] C [21.2]Apartment Driveway SBL C [22.1] D [29.2]

(4) Richmond Highway (Route 1)/ Signal EBL E (60.0) E (65.0)Ladson Lane EBR D (47.8) D (48.8)

NBL E (67.9) E (58.2)NBT A (5.6) A (7.3)SBTR B (17.3) B (12.5)

Overall B (15.2) B (13.1)

(5) Richmond Highway (Route 1)/ Signal EBL E (75.4) F (112.3)Mount Vernon Highway/ EBLTR E (75.0) F (111.5)Buckman Road WBLT E (78.5) E (68.5)

WBR F (87.4) F (298.1)NBL C (24.7) C (29.2)

NBTR D (42.1) D (50.0)SBL F (80.6) F (99.5)SBT A (7.3) B (14.7)SBR B (10.6) C (20.3)

Overall D (35.7) E (72.7)

(6) Site Entrance/ STOP EBLT A [0.5] A [0.8]Ladson Lane SBL B [12.2] B [11.8]

SBR A [9.8] A [9.5]

(7) Audubon Avenue/ All-Way STOP WBLR A [7.8] A [7.4]Ladson Lane NBTR A [7.7] A [7.4]

SBLT A [9.3] A [8.8]Overall A [8.3] A [7.9]

Notes:

(1) Analysis performed using Synchro software, version 7

(2) Values in parentheses, ( ), represent signalized delay in seconds

(3) Values in brackets, [ ], represent unsignalized delay in seconds

2010 Existing

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SECTION 4 ANALYSIS OF FUTURE CONDITIONS WITHOUT DEVELOPMENT METHODOLOGY The future traffic forecasts without the proposed new Costco were developed based on a composite of existing baseline traffic volumes, regional growth, and projected traffic volumes anticipated to be generated by other area development projects (“pipeline projects”). This methodology was discussed with VDOT and County staff and approved as reflected in the scoping agreement signed by all parties and is consistent with 24 VAC 30-155-60.D. REGIONAL GROWTH Regional traffic growth factors were developed for the study area based on a review of VDOT historic traffic counts, as well as regional traffic models. Upon review, additional discussions/correspondence was held with VDOT and the County in order to come to agreement on the appropriate growth factors. Based on the aforementioned, an annual compound rate of 1.5% was applied to volumes on Route 1 for both study years (2013 and 2019). Existing volumes on Sherwood Hall Lane, Buckman Road and Mount Vernon Highway were grown at a rate of 1% per year compounded. Given its configuration as a tertiary street, no growth was applied to Ladson Lane. The resulting regional growth at each of the study intersections for years 2013 and 2019 are depicted on Figures 4-1 and 4-2, respectively.

PIPELINE PROJECTS As discussed with County and VDOT staff, traffic generated by two other developments, Mount Vernon Gateway and the Fort Belvoir Base Realignment and Closure (BRAC), was to be included in the estimation of future traffic forecasts. A description of these developments is provided below and the site locations are shown in Figure 4-3. Fort Belvoir (BRAC). Base Realignment and Closure (BRAC) is the process the Department of Defense (DoD) uses to reorganize its facilities to more efficiently and effectively support its forces, increase operational readiness and facilitate new ways of doing business. As a result of BRAC 2005, DoD will be moving thousands of jobs from leased office space and other facilities in the Washington metro region to Fort Belvoir (including the Engineer Proving Ground) in southern Fairfax County. The Army’s preferred alternative proposes approximately seven million square feet of new and renovated facilities. This would result in increasing the assigned personnel at Fort Belvoir with the relocation of 22,000 persons. A summary and location of this new and renovated development is shown on Figures 4-4 and 4-5, respectively. The BRAC changes go into effect in September 2011 therefore the impact of the BRAC is reflected in the 2013 traffic forecasts. In order to account for the increase in traffic generated in the Route 1 corridor as a result of the Ft. Belvoir BRAC, W+A reviewed the Final Environmental Impact Statement for Implementation of 2005 Base Realignment and Closure (BRAC) Recommendations and Related

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Army Actions at Fort Belvoir, Virginia prepared by Tetra Tech Inc. dated June 2007. Trips generated by the BRAC were developed by subtracting the “No Build Alternative” projections from the “Preferred Build Alternative.” Saturday peak hour trips were assumed to approximately 27.5% of the PM peak hour weekday traffic consistent with ITE data for general office uses (Land Use Code 710). Inbound and outbound assignments were also based on ITE data for general office buildings (54% inbound; 46% outbound.) The resulting BRAC assignments are depicted on Figure 4-6. Copies of relevant excerpts from the EIS are provided in Appendix J. Mount Vernon Gateway. Mount Vernon Gateway is a mixed-use development located south of the subject site, on the west side of Richmond Highway and east of Buckman Road. The property is currently zoned PDH-30, consistent with proffers dated July 19, 2005 and accepted by the Board of Supervisors on August 1, 2005. A copy of the proffers and development plan are included herein as Appendix K. The project, upon completion and occupancy would include 432 residential dwelling units, as well as 71,760 GSF of office uses. In order to accommodate this level of development, the Applicant/Owner committed to a number of transportation improvements/enhancements including those discussed in an earlier section of this report. For purposes of this assessment, the development and accompanying proffered improvements were assumed complete by 2019. The lane use and traffic controls associated with the build out of Mount Vernon Gateway (year 2019) are reflected on Figure 4-7. The trips generated by Mount Vernon Gateway during the PM and Saturday peak hours were developed based on a review of the methodologies set forth in the traffic impact

study completed by Wells + Associates dated June 15, 2005 and supplemental memoranda dated June 17, 2005. The resulting peak hour trip assignments are presented on Figure 4-8 summarized in Appendix L. Traffic Reassignments. As stated above and reflected in the proffers and on Figure 4-7, the Applicant/Owner of Mount Vernon Gateway proffered a number of transportation improvements. As a result of these improvements, certain movements at the Route 1/Buckman Road/Mount Vernon Highway intersection would be restricted. Specifically, the eastbound Buckman Road approach would be restricted to right-in/right-out movements only and westbound through movements from Mount Vernon Highway would also be eliminated. The restriction of certain of these movements would result in a redistribution or reassignment of traffic volumes under 2019 conditions. These resulting reassignments are depicted on Figure 4-9. FUTURE TRAFFIC FORECASTS WITHOUT THE SITE DEVELOPMENT Total future traffic forecasts without the proposed new Costco were developed based on a composite of existing traffic (Figure 3-1), regional growth (Figures 4-1 and 4-2), traffic from one or more pipeline developments (Figures 4-6 and 4-8), and those traffic reassignments (Figure 4-9) as applicable. The resulting total future background forecasts are shown on Figures 4-10 and 4-11 for year 2013 and 2019, respectively.

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OPERATIONAL ANALYSIS Total future background peak hour levels of service without the proposed Costco Warehouse are summarized on Table 4-1. The results were calculated at the key study intersections based on the existing/planned lane use and traffic controls shown on Figures 2-4 (2013) and 4-7 (2019), the background future traffic forecasts shown on Figures 4-10 (2013) and 4-11 (2019), and the Highway Capacity Manual methodology as reported by Synchro. The Synchro analysis results for 2013 and 2019 background future conditions are summarized on Figures 4-12 and 4-13, respectively. The capacity analysis worksheets are included in Appendices M and N for the 2013 and 2019 future conditions without the proposed development. As shown on Table 4-1, the results of the background future intersection capacity analyses indicate the following: Year 2013 1. Under the 2013 future conditions without

the proposed development, the Richmond Highway (Route 1)/Ladson Lane signalized intersection would operate at overall LOS “B” or better during the weekday PM and Saturday mid-day peak periods.

2. Under 2013 conditions, the Richmond Highway (Route 1)/Sherwood Hall Lane/Wal-Mart Driveway intersection would operate near capacity at LOS“E” during PM peak period and at capacity during the Saturday peak period.

3. Under the 2013 conditions, the Richmond Highway/Mount Vernon Highway/Buckman Road intersection would operate near capacity at LOS “E” during the Saturday peak period.

4. At all three (3) signalized intersections on Richmond Highway, lane groups would continue to operate at, or near capacity, similar to existing conditions but with higher delays.

5. Critical movements at each of the STOP

controlled intersections would operate at an acceptable LOS “D” or better during the PM and Saturday peak periods.

Year 2019 1. Under the 2019 future conditions without

the proposed development, the Richmond Highway (Route 1)/Ladson Lane signalized intersection would operate at overall LOS “C” or better during the weekday PM and Saturday mid-day peak periods.

2. Under 2019 conditions, the Richmond Highway (Route 1)/Sherwood Hall Lane/Wal-Mart Driveway intersection would operate at capacity at LOS “F” during both the PM and Saturday peak period.

3. Under the 2019 conditions with the Mount

Vernon Gateway proffered improvements in place, the intersection would operate at an LOS “D” or better during the PM peak and Saturday peak periods.

4. At all three (3) signalized intersections on Richmond Highway, lane groups would continue to operate at, or near capacity, similar to existing conditions but with higher delays.

35

Table 4-1Costco Wholesale - Alexandria/Mount Vernon

Levels of Service without Development (1) (2) (3)

Intersection CriticalIntersection Control Movement Weekday PM Saturday Weekday PM Saturday Weekday PM Saturday

(1) Richmond Highway (Route 1)/ Signal EBL E (77.6) F (87.6) E (77.6) F (87.6) E (77.6) F (87.6)Sherwood Hall Lane/ EBT E (72.0) E (70.3) E (72.0) E (70.3) E (72.0) E (70.3)Wal-Mart Driveway EBR E (75.6) E (68.9) E (75.7) E (68.9) E (75.9) E (69.1)

WBL F (94.6) F (99.4) F (104.9) F (99.0) F (119.3) F (103.2)WBLT F (93.1) F (100.3) F (99.9) F (97.5) F (123.9) F (105.8)WBR D (46.3) E (63.0) D (46.3) E (63.1) D (46.4) E (62.9)NBL F (115.8) F (89.3) F (122.6) F (90.7) F (142.5) F (99.1)

NBTR E (68.7) E (56.3) F (139.4) F (83.1) F (205.2) F (151.9)SBL E (74.4) F (105.3) E (74.9) F (109.4) E (76.4) F (122.7)SBT D (47.8) D (37.4) E (60.7) D (40.0) F (103.7) D (48.9)SBR C (23.7) C (22.0) C (23.7) C (22.0) C (23.8) C (22.7)

Overall E (65.4) E (57.2) F (99.9) E (69.4) F (145.7) F (103.9)

(2) Richmond Highway (Route 1)/ STOP EBR B [11.1] B [10.5] B [11.9] B [10.8] B [12.0] B [11.8]Site Driveway

(3) Richmond Highway (Route 1)/ STOP WBLR B [13.2] C [21.2] B [13.0] C [19.7] B [12.4] C [19.7]Apartment Driveway SBL C [22.1] D [29.2] D [30.2] D [34.5] E [39.8] C [16.4]

(4) Richmond Highway (Route 1)/ Signal EBL E (60.0) E (65.0) E (59.9) E (64.9) E (59.8) E (64.7)Ladson Lane EBR D (47.8) D (48.8) D (47.7) D (48.8) D (47.4) D (48.5)

NBL E (67.9) E (58.2) E (70.4) E (60.0) F (87.4) E (71.0)NBT A (5.6) A (7.3) B (10.5) A (7.6) A (8.0) B (11.6)SBTR B (17.3) B (12.5) B (18.7) B (14.1) D (45.8) B (17.9)

Overall B (15.2) B (13.1) B (17.4) B (13.8) C (30.7) B (17.6)

(5) Richmond Highway (Route 1)/ Signal EBL E (75.4) F (112.3) E (75.1) F (117.7) N/A N/AMount Vernon Highway/ EBLTR E (75.0) F (111.5) E (74.5) F (117.6) N/A N/ABuckman Road WBLT E (78.5) E (68.5) E (78.2) E (70.4) N/A N/A

WBR F (87.4) F (298.1) F (85.1) F (309.7) N/A N/ANBL C (24.7) C (29.2) C (28.0) C (28.4) N/A N/A

NBTR D (42.1) D (50.0) D (48.8) D (50.4) N/A N/ASBL F (80.6) F (99.5) F (80.9) F (111.4) N/A N/ASBT A (7.3) B (14.7) A (7.8) B (12.8) N/A N/ASBR B (10.6) C (20.3) A (8.4) B (13.0) N/A N/A

Overall D (35.7) E (72.7) D (37.0) E (71.3) N/A N/A

Proffered Improvements (Mount Vernon Gateway) EBR N/A N/A N/A N/A A (0.0) A (0.0)Right-In, Right-Out Buckman Road WBL N/A N/A N/A N/A E (72.3) E (59.8)Free-Flow Eastbound Right WBR N/A N/A N/A N/A F (82.3) F (108.6)Free-Flow Southbound Right NBTR N/A N/A N/A N/A D (39.8) E (61.4)

SBL N/A N/A N/A N/A F (81.6) F (111.9)SBT N/A N/A N/A N/A A (6.0) B (12.1)SBR N/A N/A N/A N/A A (0.1) A (0.5)

Overall N/A N/A N/A N/A C (30.0) D (50.1)

(6) Site Entrance/ STOP EBLT A [0.5] A [0.8] A [0.5] A [0.8] A [0.5] A [0.8]Ladson Lane SBL B [12.2] B [11.8] B [12.0] B [11.6] B [12.1] B [11.6]

SBR A [9.8] A [9.5] A [9.8] A [9.4] A [9.8] A [9.5]

(7) Audubon Avenue/ All-Way STOP WBLR A [7.8] A [7.4] A [7.7] A [7.3] A [7.8] A [7.3]Ladson Lane NBTR A [7.7] A [7.4] A [7.6] A [7.3] A [7.7] A [7.3]

SBLT A [9.3] A [8.8] A [9.2] A [8.7] A [9.3] A [8.8]Overall A [8.3] A [7.9] A [8.2] A [7.8] A [8.2] A [7.8]

Notes:




2010 Existing 2013 Background Future 2019 Background Future


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STOP

STOP

STOP

STOP

F/E

B/B

D/E

A/A

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STOP

STOP

STOP

STOP

F/F

C/B

C/D

A/A

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5. Critical movements at each of the STOP controlled intersections would operate at an acceptable LOS “D” or better during the PM and Saturday peak periods with an exception of the southbound left movement at the Richmond Highway/Apartment Driveway intersection. At this intersection, the southbound left movement would operate near capacity (LOS “E”) during the PM peak period.

39



SECTION 5 TRIP GENERATION, DISTRIBUTION AND ASSIGNMENT TRIP GENERATION The volume of trips generated by the proposed new Costco Wholesale warehouse was calculated using the standard rates and equations published in the Institute of Transportation Engineers (ITE) Trip Generation, Eighth Edition. The proposed new Costco consists of 143,416 GSF of building floor area. Land use code “857 Discount Club” was utilized for estimating the PM peak and Saturday peak hour trips. As reflected in the scoping agreement and as discussed previously, the AM peak hour analysis was not included in the traffic study as the proposed new Costco would not be open for business coincident with the AM peak hour of the adjacent street (6:00 to 9:00 AM). The proposed new use would generate a total of 608 weekday PM peak hour trips (304 in and 304 out), 982 Saturday peak hour trips (481 in and 501 out), and 5,995 average daily (24-hour) trips at build out. A summary of the trip generation information is shown on Table 5-1. Pass-by Trip Reductions. According to ITE, in some cases the driveway volumes at a particular land use are different from the amount of traffic added to the adjacent street system. Commercial uses such as the proposed new Costco Wholesale discount club attract a portion of their trips from traffic that is already on the road network. Pass-by trips are those trips, which are made as intermediate stops on the way to a primary destination. An example of a pass-by trip would be one in which a driver stops at a retail store on his/her way home from work.

In accordance with VDOT standards (Traffic Impact Analysis Regulations Administrative Guidelines 24 VAC 30-155), and consistent with the scoping agreement a pass-by reduction of 25% was applied to the proposed commercial use. The site pass-by trip assignments are summarized on Figure 5-1. Primary Site Trips. As shown on Table 5-1, the net new trips associated with the proposed Costco Wholesale warehouse are 456 new weekday PM peak hour trips (228 in and 228 out), 737 new Saturday mid-day peak (361 in and 376 out), and 4,496 new average weekday trips. SITE TRIP DISTRIBUTION AND ASSIGNMENT Site Access. Access to the site is currently provided via a full movement entrance on Ladson Lane and a right-in/right-out access on Route 1. The full movement entrance on Ladson Lane operates under STOP control and is currently located approximately 250 feet west of the Richmond Highway/Ladson Lane intersection (measured centerline to centerline). The right-in/right-out access is located on Richmond Highway approximately 635 feet north of the Richmond Highway/Ladson Lane intersection (measured centerline to centerline). An interparcel connection to the Wal-Mart property to the north is also available for use and will be retained.

40

Tab

le 5

-1C

ostc

o W

hole

sale

- A

lexa

ndri

a/M

ount

Ver

non

Tri

p G

ener

atio

n

Scen

ario

Land

Use

PM P

eak

Hou

rSa

t Pe

ak H

our

Wee

kday

Ave

rage

Satu

rday

Ave

rage

Cod

eA

mou

ntU

nits

InO

utT

otal

InO

utT

otal

Dai

ly T

rips

Dai

ly T

rips

Cos

tco

Who

lesa

le (

Dis

coun

t C

lub)

857

143,

416

SF30

430

460

848

150

198

25,

995

7,70

9

Pass

-by

Trip

s25

%(7

6)(7

6)(1

52)

(120

)(1

25)

(245

)(1

,499

)(1

,927

)

Tot

al N

ew C

ostc

o W

hole

sale

Tri

ps22

822

845

636

137

673

74,

496

5,78

2

Not

e(s)

:

(1)

Tri

p ge

nera

tion

base

d on

the

Inst

itute

of T

rans

port

atio

n En

gine

ers'

Tri

p G

ener

atio

n , 8

th E

ditio

n.

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Based on the Special Exception (SE) plat provided by Bohler Engineering, no new access points are proposed (see Figure 2-3). However, the full movement entrance on Ladson Lane would be relocated approximately 380 feet west of its current location. This entrance relocation provides for increased separation from Richmond Highway. The existing connection to the Wal-Mart would continue to provide interparcel access between the subject site and the Wal-Mart. The new (primary) site-generated trips outlined above were assigned to the roadway network based on the existing/future site access, current and forecasted travel patterns, surrounding residential locations and engineering judgment consistent with the scoping document. It should be noted site trip distributions vary slightly between the 2013 to 2019 study years as a result of the modifications to the Richmond Highway/Buckman Road/Mount Vernon Highway intersection. The site traffic assignments and directional distributions are shown on Figure 5-2 and Figure 5-3 for study years 2013 and 2019, respectively.

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Lane

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35%

12%

1%

1%

8%

35%

8%

44

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35%

12%

1%

1%

8%

35%

8%

45



SECTION 6 ANALYSIS OF 2013 FUTURE CONDITIONS WITH DEVELOPMENT FUTURE TRAFFIC CONDITIONS WITH THE PROPOSED NEW USE Future Traffic Forecasts. The 2013 total future traffic forecasts were developed using the 2013 background forecasts shown on Figure 4-10, the pass-by trip assignments shown on Figure 5-1 and the site “new primary” trip assignments shown on Figures 5-2. The resulting 2013 total future traffic forecasts are shown on Figure 6-1. OPERATIONAL ANALYSIS. Future peak hour levels of service, with the proposed development, were determined at the key study intersections and driveways based on the total future traffic forecasts shown on Figure 6-1, the future lane use and traffic control shown on Figure 6-2, and the Highway Capacity Manual methodology. The Synchro results for the 2013 future conditions are presented in Appendix O and summarized in Table 6-1. The results are also shown on Figure 6-3. The results of the 2013 future conditions with the proposed new Costco indicate the following: 1. Under the 2013 future conditions with the

proposed new use, at each of the signalized intersections, a majority of the side street movements and the mainline left-turn movements would continue to operate at capacity consistent with future background conditions (or without the new use).

2. Under the 2013 total future conditions the Richmond Highway/Sherwood Hall Lane/ Wal-Mart Driveway intersection would degrade to overall LOS “F” during the Saturday peak period.

3. The Richmond Highway/Mount Vernon Highway/Buckman Road intersection would degrade to overall LOS “F” during the Saturday peak period.

4. The southbound approach at the STOP

controlled intersection of Ladson Lane and the Costco entrance would operate near capacity during the Saturday peak period.

5. Under 2013 total future conditions, all

other critical movements at each of the STOP controlled intersections would operate at an acceptable LOS “D” or better during the PM and Saturday peak periods, with an exception of the southbound left movement at the Richmond Highway/ Apartment Driveway intersection. At this intersection, the southbound left movement would operate near capacity during the 2013 Saturday peak period.

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2013 Levels of Service with Development (1) (2) (3)


(1) Richmond Highway (Route 1)/ Signal EBL E (77.6) F (87.6) E (77.6) F (87.6) F (84.7) F (103.3)Sherwood Hall Lane/ EBT E (72.0) E (70.3) E (72.0) E (70.3) E (72.1) E (70.2)Wal-Mart Driveway EBR E (75.6) E (68.9) E (75.7) E (68.9) E (75.0) E (68.1)


NBTR E (68.7) E (56.3) F (139.4) F (83.1) F (158.3) F (115.3)SBL E (74.4) F (105.3) E (74.9) F (109.4) E (74.9) F (112.4)SBT D (47.8) D (37.4) E (60.7) D (40.0) E (69.8) D (46.0)SBR C (23.7) C (22.0) C (23.7) C (22.0) C (23.8) C (23.3)

Overall E (65.4) E (57.2) F (99.9) E (69.4) F (113.2) F (87.5)


(3) Richmond Highway (Route 1)/ STOP WBLR B [13.2] C [21.2] B [13.0] C [19.7] B [13.8] C [19.6]Apartment Driveway SBL C [22.1] D [29.2] D [30.2] D [34.5] D [33.3] E [40.9]


NBL E (67.9) E (58.2) E (70.4) E (60.0) E (74.2) F (140.2)NBT A (5.6) A (7.3) B (10.5) A (7.6) B (10.6) A (6.7)SBTR B (17.3) B (12.5) B (18.7) B (14.1) E (69.5) C (26.2)

Overall B (15.2) B (13.1) B (17.4) B (13.8) D (45.3) C (27.3)

(5) Richmond Highway (Route 1)/ Signal EBL E (75.4) F (112.3) E (75.1) F (117.7) E (76.4) F (140.9)Mount Vernon Highway/ EBLTR E (75.0) F (111.5) E (74.5) F (117.6) E (75.3) F (137.7)Buckman Road WBLT E (78.5) E (68.5) E (78.2) E (70.4) E (77.3) E (71.6)

WBR F (87.4) F (298.1) F (85.1) F (309.7) F (100.6) F (412.2)NBL C (24.7) C (29.2) C (28.0) C (28.4) C (31.2) C (28.9)

NBTR D (42.1) D (50.0) D (48.8) D (50.4) E (56.5) D (52.9)SBL F (80.6) F (99.5) F (80.9) F (111.4) E (79.8) F (133.1)SBT A (7.3) B (14.7) A (7.8) B (12.8) A (9.0) B (12.1)SBR B (10.6) C (20.3) A (8.4) B (13.0) A (8.7) A (9.9)

Overall D (35.7) E (72.7) D (37.0) E (71.3) D (41.1) F (84.3)

Proffered Improvements (Mount Vernon Gateway) EBR N/A N/A N/A N/A N/A N/ARight-In, Right-Out Buckman Road WBL N/A N/A N/A N/A N/A N/AFree-Flow Eastbound Right WBR N/A N/A N/A N/A N/A N/AFree-Flow Southbound Right NBTR N/A N/A N/A N/A N/A N/A

SBL N/A N/A N/A N/A N/A N/ASBT N/A N/A N/A N/A N/A N/ASBR N/A N/A N/A N/A N/A N/A

Overall N/A N/A N/A N/A N/A N/A

(6) Site Entrance/ STOP EBLT A [0.5] A [0.8] A [0.5] A [0.8] A [0.8] A [1.3]Ladson Lane SBL/SBLR B [12.2] B [11.8] B [12.0] B [11.6] C [19.4] E [36.8]

SBR A [9.8] A [9.5] A [9.8] A [9.4] N/A N/A



Notes:




2010 Existing 2013 Background Future 2013 Total Future


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STOP

STOP

STOP

F/F

D/C

D/F

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SECTION 7 IMPROVEMENT ANALYSIS OVERVIEW The following transportation improvements are recommended to mitigate the impacts associated with regional background growth and the proposed new Costco at critical intersections in the study area: • Modification of the signal timing splits at the

Richmond Highway/Ladson Lane intersection to provide additional green time for heavier turn movements.

• Modification of the signal timing splits at the Richmond Highway/Sherwood Hall Lane/Wal-Mart Driveway intersection.

• Modification of the signal timing splits at the

Richmond Highway/Buckman Road/Mount Vernon Highway intersection.

• Construction of an exclusive southbound

right-turn lane at the Richmond Highway/Ladson Lane intersection.

• Construction of an exclusive westbound

right-turn lane at the Ladson Lane/Site Entrance intersection.

• Closure of the existing median break at the

intersection of Richmond Highway and entrance to the Spring Garden Apartments.

• Extension of the existing northbound left-


MEDIAN BREAK CLOSURE AT SPRING GARDEN APARTMENTS As requested by VDOT staff at the scoping meeting, the Applicant proposes to close the existing median break at the Richmond Highway/Spring Garden Apartments Entrance. As a result, the entrance to the Spring Garden Apartments would function as a right-in/right-out entrance providing access only to the northbound traffic on Richmond Highway. The southbound left-turns and U-turns at the median break were reassigned to the Richmond Highway/Ladson Lane intersection as shown on Figure 7-1. As a result, the Applicant has proposed to modify the existing signal timing and phasing to accommodate the southbound U-turns at Richmond Highway/Ladson Lane intersection. SITE TRIP ASSIGNMENTS Under the 2013 future conditions with development, the northbound left-turn lane at the Richmond Highway/Ladson Lane intersection is forecasted to operate with significantly long queues that could spill out of the existing northbound left-turn lane. Due to inadequate right-of-way at that location and steep grading issues, construction of a second northbound left-turn lane at Richmond Highway/Ladson Lane was deemed beyond the scope of this project. Alternatively, a portion of the northbound site traffic previously assigned to turn left onto Ladson Lane could potentially use the Wal-Mart entrance and access the site via the interparcel access. However, the northbound left-turn lane at Richmond Highway/Sherwood Hall Lane/Wal-Mart Driveway intersection theoretically would not have sufficient residual storage under the 2013 total future conditions with development.

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8

52



The Applicant therefore proposes to extend the northbound left-turn lane at the Wal-Mart Driveway to accommodate the reassigned site traffic. The modified site trip assignments and pass-by trips per the above discussion are provided on Figures 7-2 and 7-3. The adjusted 2013 future traffic forecasts with development are provided on Figure 7-4. The 2013 future lane use and traffic controls with all of the proposed improvements are shown on Figure 7-5. The existing northbound left-turn lane at the Richmond Highway/Sherwood Hall Lane/Wal-Mart Driveway has a storage length of approximately 385 feet. The Applicant proposes to extend that storage to approximately 625 feet. With the additional 240 feet of storage, the northbound left-turn lane could accommodate the site traffic that was reassigned from Richmond Highway/Ladson Lane intersection. IMPROVEMENT ANALYSIS Right Turn Lane Warrant Analysis. VDOT’s Road Design Manual provides warrants for determining the need for right turn lanes at signalized and unsignalized intersections. Accordingly, the warrants were evaluated at the site entrance on Ladson Lane under 2013 total future conditions. The detailed turn lane warrant analyses are included in Appendix P. These analyses indicate that full-width westbound right turn lanes would be required on Ladson Lane at the site entrance during both PM and Saturday peak hours. As shown on the Special Exception Plan completed by Bohler Engineering, a 480 foot westbound right-turn lane was proposed at the entrance on Ladson Lane. The right-turn lane would extend east from the proposed entrance to Richmond Highway.

Capacity Analysis. Future peak hour levels of service with the proposed development were determined at the key intersections based on the future lane use and traffic control shown on Figure 7-5, the 2013 total future traffic forecasts respectively shown on Figure 7-4 and the Highway Capacity Manual methodology as analyzed in Synchro. The Synchro results for improvement analysis under 2013 total future conditions are presented in Appendix Q, and summarized in Table 7-1. The level of service results are also shown on Figure 7-6. RESULTS A comparison of the results both with and without the proposed development is described below for the 2013 buildout year. The results are also summarized on Table 7-1. As shown on Table 7-1, with the improvements proposed by the Applicant, the following are indicated: 1. Richmond Highway/Sherwood Hall

Lane/Wal-Mart Driveway. As shown on Table 7-1, each of the mainline movements and side street movements at the signalized intersection of Richmond Highway/ Sherwood Hall Lane/Wal-Mart Driveway would operate generally consistent with the 2013 conditions without development. The overall intersection levels of service would also continue to operate at levels of service consistent with the 2013 conditions without development.

2. Richmond Highway/Ladson Lane. With the proposed improvements, the Richmond Highway/Ladson Lane intersection would operate at an overall LOS “C” or better during the PM peak hour and Saturday peak hour. Each of the mainline and side street movements would continue to operate

53

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STOP

STOP

STOP

STOP

F/E

C/C

D/E

A/A

58

Table 7-1Costco Wholesale - Alexandria/Mount VernonLevels of Service with Improvements (1) (2) (3)


(1) Richmond Highway (Route 1)/ Signal EBL E (77.6) F (87.6) E (77.6) F (87.6) F (84.7) F (103.3)Sherwood Hall Lane/ EBT E (72.0) E (70.3) E (72.0) E (70.3) E (72.1) E (70.2)Wal-Mart Driveway EBR E (75.6) E (68.9) E (75.7) E (68.9) E (75.0) E (68.1)


NBTR E (68.7) E (56.3) F (139.4) F (83.1) F (158.3) F (115.3)SBL E (74.4) F (105.3) E (74.9) F (109.4) E (74.9) F (112.4)SBT D (47.8) D (37.4) E (60.7) D (40.0) E (69.8) D (46.0)SBR C (23.7) C (22.0) C (23.7) C (22.0) C (23.8) C (23.3)

Overall E (65.4) E (57.2) F (99.9) E (69.4) F (113.2) F (87.5)

Site Improvement Signal EBL N/A N/A N/A N/A F (170.6) F (167.4)Modified Signal Timings (Splits) EBT N/A N/A N/A N/A E (78.9) E (75.0)Adjusted Site Distribution EBR N/A N/A N/A N/A F (117.1) E (71.9)

WBL N/A N/A N/A N/A F (114.6) F (113.6)WBLT N/A N/A N/A N/A F (109.3) F (114.6)WBR N/A N/A N/A N/A D (47.6) E (65.1)NBL N/A N/A N/A N/A F (276.9) F (162.4)

NBTR N/A N/A N/A N/A E (70.7) E (63.4)SBL N/A N/A N/A N/A F (157.4) F (176.7)SBT N/A N/A N/A N/A E (58.2) D (50.7)SBR N/A N/A N/A N/A C (22.2) C (24.8)

Overall N/A N/A N/A N/A F (82.2) E (74.4)


(3) Richmond Highway (Route 1)/ STOP WBLR B [13.2] C [21.2] B [13.0] C [19.7] B [13.8] C [19.6]Apartment Driveway SBL C [22.1] D [29.2] D [30.2] D [34.5] D [33.3] E [40.9]

Site Improvement STOP WBR N/A N/A N/A N/A B [10.4] B [11.1]Right-In, Right-Out Access


NBL E (67.9) E (58.2) E (70.4) E (60.0) E (74.2) F (140.2)NBT A (5.6) A (7.3) B (10.5) A (7.6) B (10.6) A (6.7)SBTR B (17.3) B (12.5) B (18.7) B (14.1) E (69.5) C (26.2)

Overall B (15.2) B (13.1) B (17.4) B (13.8) D (45.3) C (27.3)

Site Improvement Signal EBL N/A N/A N/A N/A E (60.0) E (65.3)Exclusive Southbound Right Turn Lane EBR N/A N/A N/A N/A D (47.7) D (46.1)Modified Signal Timings (SBU Phase & Splits) NBL N/A N/A N/A N/A E (76.8) E (64.1)Adjusted Site Distribution NBT N/A N/A N/A N/A B (16.0) B (17.7)

SBU N/A N/A N/A N/A C (23.8) C (27.6)SBT N/A N/A N/A N/A B (20.0) C (21.9)SBR N/A N/A N/A N/A A (0.1) A (0.1)

Overall N/A N/A N/A N/A C (21.4) C (23.9)


WBR F (87.4) F (298.1) F (85.1) F (309.7) F (100.6) F (412.2)NBL C (24.7) C (29.2) C (28.0) C (28.4) C (31.2) C (28.9)

NBTR D (42.1) D (50.0) D (48.8) D (50.4) E (56.5) D (52.9)SBL F (80.6) F (99.5) F (80.9) F (111.4) E (79.8) F (133.1)SBT A (7.3) B (14.7) A (7.8) B (12.8) A (9.0) B (12.1)SBR B (10.6) C (20.3) A (8.4) B (13.0) A (8.7) A (9.9)

Overall D (35.7) E (72.7) D (37.0) E (71.3) D (41.1) F (84.3)

Site Improvement Signal EBL N/A N/A N/A N/A E (76.4) F (153.3)Modified Signal Timings (Saturday) EBLTR N/A N/A N/A N/A E (75.3) F (150.3)

WBLT N/A N/A N/A N/A E (77.3) E (60.7)WBR N/A N/A N/A N/A F (100.6) F (164.4)NBL N/A N/A N/A N/A C (31.2) D (37.1)

NBTR N/A N/A N/A N/A E (56.5) E (78.7)SBL N/A N/A N/A N/A E (79.8) F (138.5)SBT N/A N/A N/A N/A A (9.0) B (18.7)SBR N/A N/A N/A N/A A (8.7) A (8.6)

Overall N/A N/A N/A N/A D (41.1) E (73.2)

(6) Site Entrance/ STOP EBLT A [0.5] A [0.8] A [0.5] A [0.8] A [0.8] A [1.3]Ladson Lane SBL/SBLR B [12.2] B [11.8] B [12.0] B [11.6] C [19.4] E [36.8]

SBR A [9.8] A [9.5] A [9.8] A [9.4] N/A N/A

Site Improvement STOP EBLT N/A N/A N/A N/A A [0.7] A [1.2]Exclusive Westbound Right Turn Lane SBLR N/A N/A N/A N/A C [16.4] C [22.3]



Notes:




2010 Existing 2013 Background Future 2013 Total Future


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STOP

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STOP

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F/E

C/C

D/E

A/A

60



consistent with the 2013 conditions without development, as shown on Table 7-1.

3. Richmond Highway/Buckman Road/Mount

Vernon Memorial Highway. With the proposed improvements, each of the mainline movements and side street movements at the signalized intersection of Richmond Highway/Buckman Road/Mount Vernon Highway would operate generally consistent with the 2013 conditions without development. The overall intersection levels of service would also continue to operate generally consistent with the 2013 without development conditions.

61



Section 8 QUEUEING ANALYSIS OVERVIEW In order to assess the adequacy of certain critical existing and proposed turn bays at select key study intersections, the 95th percentile back-of-queue results reported by Synchro were reviewed and compared to available/proposed storage lengths. The 95th percentile queue is the maximum back of queue with 95th percentile traffic volumes. The turning movements/storage bays which would be affected by the proposed site trips were assessed. The Synchro worksheets identifying the projected 95th percentile queues are included in Appendix R. Table 8-1 summarizes the forecasted 95th-percentile queues for existing, background and total future conditions. The storage lengths documented in Table 8-1 were taken from field work conducted at the study intersections. As shown in Table 8-1, many of the existing storage bay lengths would not be adequate to handle forecasted queues, with or without the site. However, with the addition of site traffic and recommended mitigation certain movements would be affected. Those intersection movements are identified below: Richmond Highway(Route 1)/Sherwood Hall Lane/Wal-Mart Driveway • Multiple movements would experience

queues that exceed available storage with or without the proposed site.

• Site traffic making the northbound left turn into the Wal-Mart driveway would extend the projected queue to fill the available storage. The extension of the turn lane would provide increased storage to accommodate increased site volumes.

Richmond Highway(Route 1)/Ladson Lane The northbound left turn movement would experience queues that exceed available storage under 2013 total future conditions. The extension of the northbound left turn lane at the Richmond Highway (Route 1)/Sherwood Hall Lane/Wal-Mart Driveway intersection would allow site traffic to shift to that intersection. The project queue would be 263 feet and would exceed available storage of 192 feet. Richmond Highway(Route 1)/Mount Vernon Highway/Buckman Road • Multiple movements would experience total

future queues exceeding available storage. This queuing would be generally consistent with background conditions without the site.

Based on the results identified above, the applicant proposes to close the median break at the Spring Garden Apartment driveway as recommended by the Route 1 Location Study and extend the northbound left turn lane at the Wal-Mart driveway to accommodate queues impacted by site traffic.

62

Tab

le 8

-1C

ostc

o W

hole

sale

- A

lexa

ndri

a/M

ount

Ver

non

Que

uing

Ana

lysi

s w

ith Im

prov

emen

ts (1

) (2

) (3

)

Inte

rsec

tion

Cri

tical

Ava

ilabl

eIn

ters

ectio

nC

ontr

olM

ovem

ent

Stor

age

Wee

kday

PM

Satu

rday

Ade

quat

e? W

eekd

ay P

MSa

turd

ayA

dequ

ate?

Wee

kday

PM

Satu

rday

Ade

quat

e? W

eekd

ay P

MSa

turd

ayA

dequ

ate?

Wee

kday

PM

Satu

rday

Ade

quat

e?

(1)

Ric

hmon

d H

ighw

ay (

Rou

te 1

)/Si

gnal

EBL

165

166

292

No

166

292

No

#211

#404

No

166

292

No

N/A

N/A

N/A

Sher

woo

d H

all L

ane /

EBT

165

8410

2Y

es84

102

Yes

103

134

Yes

8410

2Y

esN

/AN

/AN

/AW

al-M

art

Dri

vew

ayW

BL42

7#7

45#4

53N

o#7

86#4

71N

o#8

27#5

32N

o#8

44#5

09N

oN

/AN

/AN

/AW

BLT

425

#745

#461

No

#774

#471

No

#812

#543

No

#869

#528

No

N/A

N/A

N/A

NBL

385

#286

#289

Yes

m#2

96#3

03Y

es#3

53#3

82Y

esm

#281

m#3

00Y

esN

/AN

/AN

/AN

BTR

465

#106

5#5

39N

o#1

198

#695

No

#127

2#8

48N

o#1

683

#171

2N

oN

/AN

/AN

/ASB

T36

089

375

7N

o#1

086

851

No

#115

394

1N

o#1

335

1030

No

N/A

N/A

N/A

SBR

360

2632

Yes

2735

Yes

3039

Yes

3040

Yes

N/A

N/A

N/A

Site

Impr

ovem

ent

Sign

alEB

L16

5N

/AN

/AN

/AN

/AN

/AN

/A#2

83#4

64N

oN

/AN

/AN

/A#2

83#4

64N

oM

odifi

ed S

igna

l Tim

ings

(Sp

lits)

EBT

165

N/A

N/A

N/A

N/A

N/A

N/A

108

138

Yes

N/A

N/A

N/A

108

138

Yes

Mod

ified

Sit

e D

istr

ibut

ion

WBL

427

N/A

N/A

N/A

N/A

N/A

N/A

#815

#532

No

N/A

N/A

N/A

#876

#584

No

WBL

T42

5N

/AN

/AN

/AN

/AN

/AN

/A#8

01#5

43N

oN

/AN

/AN

/A#8

93#5

85N

oN

BL62

5N

/AN

/AN

/AN

/AN

/AN

/Am

#550

m#6

3 7N

oN

/AN

/AN

/Am

#507

m#5

93Y

esN

BTR

465

N/A

N/A

N/A

N/A

N/A

N/A

#584

#279

No

N/A

N/A

N/A

#753

#170

0N

oSB

T36

0N

/AN

/AN

/AN

/AN

/AN

/A#1

115

974

No

N/A

N/A

N/A

#136

3#1

226

No

SBR

360

N/A

N/A

N/A

N/A

N/A

N/A

2941

Yes

N/A

N/A

N/A

3147

Yes

(2)

Ric

hmon

d H

ighw

ay (

Rou

te 1

)/ST

OP

EBR

190

710

Yes

89

Yes

2640

Yes

811

Yes

2749

Yes

Site

Dri

vew

ay

(4)

Ric

hmon

d H

ighw

ay (

Rou

te 1

)/Si

gnal

EBL

175

9497

Yes

9495

Yes

158

210

No

9495

Yes

N/A

N/A

N/A

Lads

on L

ane

EBR

100

103

107

No

104

107

No

196

275

No

110

110

No

N/A

N/A

N/A

NBL

192

m14

3m

186

Yes

m12

8m

181

Yes

m#3

41m

#645

No

m12

723

4N

oN

/AN

/AN

/AN

BT56

530

4m

364

Yes

423

m37

7Y

es41

3m

407

Yes

256

911

No

N/A

N/A

N/A

SBT

R21

0#1

385

409

No

m#1

544

479

No

m#1

515

569

No

m#1

569

#143

3N

oN

/AN

/AN

/A

Site

Impr

ovem

ent

Sign

alEB

L17

5N

/AN

/AN

/AN

/AN

/AN

/A15

821

1N

oN

/AN

/AN

/A15

821

1N

oEx

clus

ive

Sout

hbou

nd R

ight

Tur

n La

neEB

R10

0N

/AN

/AN

/AN

/AN

/AN

/A20

527

1N

oN

/AN

/AN

/A21

427

6N

oM

odifi

ed S

igna

l Tim

ings

(SB

U P

hase

& S

plit

s)N

BL19

2N

/AN

/AN

/AN

/AN

/AN

/Am

203

m26

3N

oN

/AN

/AN

/Am

#201

m28

2N

oM

odifi

ed S

ite

Dis

trib

utio

nN

BT56

5N

/AN

/AN

/AN

/AN

/AN

/A46

4m

500

Yes

N/A

N/A

N/A

333

m56

7N

oSB

Un/

aN

/AN

/AN

/AN

/AN

/AN

/Am

11m

27Y

esN

/AN

/AN

/Am

9m

24Y

esSB

T21

0N

/AN

/AN

/AN

/AN

/AN

/Am

1322

536

No

N/A

N/A

N/A

m#1

379

m56

7N

oSB

R80

N/A

N/A

N/A

N/A

N/A

N/A

m0

m0

Yes

N/A

N/A

N/A

m0

m0

Yes

(5)

Ric

hmon

d H

ighw

ay (

Rou

te 1

)/Si

gnal

EBL

140

258

#398

No

263

#413

No

277

#463

No

N/A

N/A

N/A

N/A

N/A

N/A

Mou

nt V

erno

n H

ighw

ay/

WBR

110

#234

#726

No

#248

#757

No

#304

#840

No

N/A

N/A

N/A

N/A

N/A

N/A

Buck

man

Roa

dN

BTR

415

679

679

No

#932

757

No

#100

484

5N

oN

/AN

/AN

/AN

/AN

/AN

/ASB

L42

2m

423

#716

No

m41

1#7

74N

om

373

m#6

69N

oN

/AN

/AN

/AN

/AN

/AN

/ASB

T61

017

519

0Y

es18

919

9Y

esm

195

m25

8Y

esN

/AN

/AN

/AN

/AN

/AN

/ASB

R61

0m

3329

Yes

m33

31Y

esm

23m

22Y

esN

/AN

/AN

/AN

/AN

/AN

/A

Site

Impr

ovem

ent

Sign

alEB

L14

0N

/AN

/AN

/AN

/AN

/AN

/A27

7#4

73N

oN

/AN

/AN

/AN

/AN

/AN

/AM

odifi

ed S

igna

l Tim

ings

(Sa

turd

ay)

WBR

110

N/A

N/A

N/A

N/A

N/A

N/A

#304

#719

No

N/A

N/A

N/A

N/A

N/A

N/A

NBT

R41

5N

/AN

/AN

/AN

/AN

/AN

/A#1

004

#983

No

N/A

N/A

N/A

N/A

N/A

N/A

SBL

422

N/A

N/A

N/A

N/A

N/A

N/A

m45

9m

#857

No

N/A

N/A

N/A

N/A

N/A

N/A

SBT

610

N/A

N/A

N/A

N/A

N/A

N/A

#220

496

Yes

N/A

N/A

N/A

N/A

N/A

N/A

SBR

610

N/A

N/A

N/A

N/A

N/A

N/A

m32

m36

Yes

N/A

N/A

N/A

N/A

N/A

N/A

Prof

fere

d Im

prov

emen

ts (

Mou

nt V

erno

n G

atew

ay)

WBR

110

N/A

N/A

N/A

N/A

N/A

N/A

N/A

N/A

N/A

#271

#590

No

#333

#693

No

Rig

ht-I

n, R

ight

-Out

Buc

kman

Roa

dN

BTR

415

N/A

N/A

N/A

N/A

N/A

N/A

N/A

N/A

N/A

1052

#112

3N

o11

20#1

326

No

Free

-Flo

w E

astb

ound

Rig

htSB

L42

2N

/AN

/AN

/AN

/AN

/AN

/AN

/AN

/AN

/Am

489

#833

No

m51

8m

#780

No

Free

-Flo

w S

outh

boun

d R

ight

SBT

610

N/A

N/A

N/A

N/A

N/A

N/A

N/A

N/A

N/A

m16

956

6Y

esm

144

m79

Yes

SBR

610

N/A

N/A

N/A

N/A

N/A

N/A

N/A

N/A

N/A

m0

0Y

esm

0m

0Y

es

(6)

Site

Ent

ranc

e/ST

OP

EBLT

145

11

Yes

11

Yes

12

Yes

11

Yes

12

Yes

Lads

on L

ane

SBL/

SBLR

N/A

10

Yes

10

Yes

6117

4Y

es1

0Y

es51

113

Yes

SBR

N/A

22

Yes

12

Yes

N/A

N/A

N/A

12

Yes

N/A

N/A

N/A

(7)

Aud

ubon

Ave

nue/

All-

Way

ST

OP

(4)

WBL

R10

0N

/AN

/AN

/AN

/AN

/AN

/AN

/AN

/AN

/AN

/AN

/AN

/AN

/AN

/AN

/ALa

dson

Lan

eN

BTR

85N

/AN

/AN

/AN

/AN

/AN

/AN

/AN

/AN

/AN

/AN

/AN

/AN

/AN

/AN

/ASB

LT15

0N

/AN

/AN

/AN

/AN

/AN

/AN

/AN

/AN

/AN

/AN

/AN

/AN

/AN

/AN

/A

Not

es:

(1)

Que

ue le

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is b

ased

on

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95th

per

cent

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r 95

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ntile

que

ue is

met

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by

upst

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sig

nal.

(4)

No

queu

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ngth

giv

en fo

r al

l-way

ST

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rolle

d in

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ectio

ns u

sing

HC

M m

etho

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gies

.

2010

Exi

stin

g20

13 B

ackg

roun

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ture

2013

Tot

al F

utur

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19 B

ackg

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d Fu

ture

2019

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al F

utur

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63



SECTION 9 ANALYSIS OF 2019 FUTURE CONDITIONS WITH DEVELOPMENT FUTURE TRAFFIC FORECASTS WITH THE SITE DEVELOPMENT The 2019 total future traffic forecasts were developed using the 2019 background forecasts shown on Figure 4-11, the pass-by trip assignments shown on Figure 5-1 and the site “new primary” trip assignments shown on Figures 5-3. The resulting 2019 total future traffic forecasts are shown on Figure 9-1. OPERATIONAL ANALYSIS Future peak hour levels of service, with the proposed development, were determined at the key study intersections and driveways based on the total future traffic forecasts shown on Figure 9-1, the future lane use and traffic control with proposed improvements shown on Figure 9-2, and the Highway Capacity Manual methodology. The Synchro results for the 2019 future conditions are presented in Appendix S and summarized in Table 9-1. The results are also shown on Figure 9-3. The results of the 2019 future conditions with the proposed development indicate the following:

1. Under the 2019 future conditions with the

proposed development, at each of the signalized intersections, a majority of the side street movements and the mainline left-turn movements would continue to operate at capacity consistent with the conditions without the development.

2. Under the 2019 total future conditions the Richmond Highway/Sherwood Hall Lane/Wal-Mart Driveway intersection would operate at overall LOS “F” during both peak periods. Overall delays would be less than 2019 background conditions without proposed site mitigation.

3. The Richmond Highway/Mount Vernon

Highway/Buckman Road intersection would degrade to overall LOS “E” during the Saturday peak period.

4. Under 2019 total future conditions, all

other critical movements at each of the STOP controlled intersections would operate at an acceptable LOS “D” or better during the PM and Saturday peak periods.

64

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Highway

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1

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3 5

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3

4

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6

8

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on

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Highway

12

3

4

5

6

8

Audub

on

7

Lane

Avenue

8

Inte

rnal

Driv

eway

6

1

42

8 7

3 51

STOP

STOP

STOP

STOP

66

Table 9-1Costco Wholesale - Alexandria/Mount Vernon2019 Levels of Service with Improvements (1) (2) (3)

Intersection CriticalIntersection Control Movement Weekday PM Saturday Weekday PM Saturday

(1) Richmond Highway (Route 1)/ Signal EBL E (77.6) F (87.6) N/A N/ASherwood Hall Lane/ EBT E (72.0) E (70.3) N/A N/AWal-Mart Driveway EBR E (75.9) E (69.1) N/A N/A

WBL F (119.3) F (103.2) N/A N/AWBLT F (123.9) F (105.8) N/A N/AWBR D (46.4) E (62.9) N/A N/ANBL F (142.5) F (99.1) N/A N/A

NBTR F (205.2) F (151.9) N/A N/ASBL E (76.4) F (122.7) N/A N/ASBT F (103.7) D (48.9) N/A N/ASBR C (23.8) C (22.7) N/A N/A

Overall F (145.7) F (103.9) N/A N/A

Site Improvement Signal EBL N/A N/A F (170.6) F (167.4)Modified Signal Timings (Splits) EBT N/A N/A E (78.9) E (75.0)Adjusted Site Distribution EBR N/A N/A F (121.4) E (71.9)

WBL N/A N/A F (131.0) F (132.0)WBLT N/A N/A F (135.2) F (130.7)WBR N/A N/A D (48.0) E (65.7)NBL N/A N/A F (306.1) F (182.7)

NBTR N/A N/A F (120.0) F (108.8)SBL N/A N/A F (188.7) F (213.9)SBT N/A N/A F (98.8) E (71.2)SBR N/A N/A C (22.3) C (25.0)

Overall N/A N/A F (120.2) F (103.4)

(2) Richmond Highway (Route 1)/ STOP EBR B [12.0] B [11.8] B [13.9] C [15.7]Site Driveway

(3) Richmond Highway (Route 1)/ STOP WBLR B [12.4] C [19.7] N/A N/AApartment Driveway SBL E [39.8] C [16.4] N/A N/A

Site Improvement STOP WBR N/A N/A C [16.7] C [16.6]Right-In, Right-Out Access

(4) Richmond Highway (Route 1)/ Signal EBL E (59.8) E (64.7) N/A N/ALadson Lane EBR D (47.4) D (48.5) N/A N/A

NBL F (87.4) E (71.0) N/A N/ANBT A (8.0) B (11.6) N/A N/ASBTR D (45.8) B (17.9) N/A N/A

Overall C (30.7) B (17.6) N/A N/A

Site Improvement Signal EBL N/A N/A E (59.9) E (64.9)Exclusive Southbound Right Turn Lane EBR N/A N/A D (47.2) D (45.5)Modified Signal Timings (SBU Phase & Splits) NBL N/A N/A F (88.3) E (72.5)Adjusted Site Distribution NBT N/A N/A B (12.4) C (25.0)

SBU N/A N/A C (32.8) D (37.1)SBT N/A N/A D (42.7) C (27.3)SBR N/A N/A A (0.0) A (0.1)

Overall N/A N/A C (30.7) C (29.5)

(5) Richmond Highway (Route 1)/ Signal EBR A (0.0) A (0.0) A (0.0) A (0.0)Mount Vernon Highway/ WBL E (72.3) E (59.8) F (80.3) E (63.1)Buckman Road WBR F (82.3) F (108.6) F (92.9) F (139.9)

NBTR D (39.8) E (61.4) D (45.6) F (83.4)Proffered Improvements (Mount Vernon Gateway) SBL F (81.6) F (111.9) F (91.4) F (139.7)

Right-In, Right-Out Buckman Road SBT A (6.0) B (12.1) A (5.0) A (3.0)Free-Flow Eastbound Right SBR A (0.1) A (0.5) A (0.1) A (0.2)Free-Flow Southbound Right Overall C (30.0) D (50.1) C (33.5) E (61.6)

(6) Site Entrance/ STOP EBLT A [0.5] A [0.8] N/A N/ALadson Lane SBL/SBLR B [12.1] B [11.6] N/A N/A

SBR A [9.8] A [9.5] N/A N/A

Site Improvement STOP EBLT N/A N/A A [0.7] A [1.2]Exclusive Westbound Right Turn Lane SBLR N/A N/A C [16.8] C [22.7]

(7) Audubon Avenue/ All-Way STOP WBLR A [7.8] A [7.3] A [8.4] A [7.4]Ladson Lane NBTR A [7.7] A [7.3] A [8.0] A [7.4]

SBLT A [9.3] A [8.8] B [11.1] A [8.8]Overall A [8.2] A [7.8] A [9.6] A [7.9]

Notes:




2019 Total Future2019 Background Future


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STOP

STOP

STOP

STOP

F/F

C/C

C/E

A/A

68



SECTION 10 ACCESS MANAGEMENT In 2007, the Virginia General Assembly unanimously approved legislation to direct the VDOT commissioner to develop and implement access management regulations and standards with the goals of: • Reducing traffic congestion, • Enhancing public safety by decreasing traffic

crash rates, • Supporting economic development by

promoting the efficient movement of people and goods,

• Reducing the need for new highways and road widening by maximizing the performance of the existing state highways, and

• Preserving the public investment in new highways.

Implementation was phased by roadway functional classification. The standards were imposed on principal arterials statewide, effective July 1, 2008. Implementation with regards to minor arterials, collectors, and local streets became effective on October 14, 2009 and has been incorporated as Appendix F of the VDOT Road Design Manual. The intent of these new regulations (24VAC 30-73) is to provide the means to “control the location, spacing, design, and operation of entrances, median openings, traffic signals, and interchanges for purposes of providing vehicular access to land development in a manner that preserves the safety and efficiency of the transportation system.” These new regulations are not “retroactive” and will be assessed at time of new permit application. Entrance locations identified on proffered development plans, subdivision plats and site plans approved prior to October 14, 2009 will be exempt from spacing standards.

According to VDOT’s map of Principal Arterials for Access Management Regulations, Richmond Highway (Route 1) is classified as an “Urban Principal Arterial.” Ladson Lane is classified as an “Urban Local” roadway by VDOT. The spacing standards relative to that functional classification and the location of the proposed new entrances on Richmond Highway and Ladson Lane relative to up and downstream curb cuts must be evaluated. A copy of the entrance standards associated with principal arterials is provided herein as Appendix T. The existing partial access, two-way, entrance on Richmond Highway is located approximately 218 feet south of the Wal-Mart entrance/ Sherwood Hall Lane intersection and 630 feet north of Ladson Lane. According to the regulations for principal arterials with a 45 mph speed limit, partial access, two way entrances should be spaced at least 325 feet apart, measured from centerline to centerline. Therefore, the proposed site access on Richmond Highway does not meet the current spacing requirement and would require exceptions for access management. On Ladson Lane, a full access, two-way, entrance is proposed approximately 620 feet east of Richmond Highway and approximately 400 feet west of Audubon Avenue (private street). According to the regulations for urban local roads with a 25 mph speed limit, full access, two-way entrances should be spaced at least 50 feet apart. Additionally, according to the VDOT Road Design Manual, Appendix F, commercial entrances on side streets must be placed at a minimum distance of 225 feet from the side street’s intersection with a major street. This minimum distance is defined as “Corner Clearance,” and is measured perpendicular to the major roadway, from the

69



nearest edge of an entrance on the minor side street to the nearest edge pavement of the major roadway intersection. The proposed/ relocated entrance to Costco would be located at a distance of 620 feet from Richmond Highway measured centerline to centerline, which is significantly greater than the minimum requirement of 225 feet. Therefore, the proposed local street would not require exceptions for access management, as a full access, two-way entrance.

70



SECTION 11 ANALYSIS OF FUTURE CONDITIONS WITH ALTERNATIVE DEVELOPMENT OPTIONS OVERVIEW As stated previously, the subject site is currently zoned C-8 (Highway Commercial). As such, the property could be developed up to a FAR of 0.5 by-right. This level of development would yield a total of 258,746 gross square feet of retail floor area on the property. In order to provide a comparison between the by-right retail uses and the Applicant’s proposal two alternative development proposals were analyzed and compared to the results of the 2013 total future analysis (Section 6 of this report). The first alternative analyzed the subject site as general retail at the by-right density of 0.5 FAR. The second alternative analyzed the site with the existing movie theater in operation. TRIP GENERATION The volume of trips generated by the two development alternatives was calculated using the standard rates and equations published in the Institute of Transportation Engineers (ITE) Trip Generation, Eighth Edition. The results are shown in Table 11-1. The general by-right retail option of 258,746 GSF of building floor area would generate 1,203 PM peak hour trips, 1,590 Saturday midday peak hour trips, 12,598 weekday daily trips and 16,818 Saturday daily trips. Consistent with VDOT guidelines, a 25 percent pass-by reduction was assumed. The movie theater alternative would generate 257 PM peak hour trips and 274 Saturday midday peak hour trips. No rates were

provided by ITE for daily trips generation. Due to the nature of the movie theater use, no pass-by reduction was assumed. The alternative site trips were assigned to the roadway network based on the distributions utilized for the 2013 total future analyses. Retail pass-by trip assignments are shown on Figure 11-1. The retail primary site trip assignments are shown on Figure 11-2. The movie theater trip assignments are shown on Figure 11-3. FUTURE TRAFFIC FORECASTS WITH THE ALTERNATIVE DEVELOPMENT The 2013 total future traffic forecasts with the retail alternative were developed using the 2013 background forecasts shown on Figure 4-10, the pass-by trip assignments shown on Figure 11-1 and the site “new primary” trip assignments shown on Figures 11-2. The resulting 2013 retail alternative forecasts are shown on Figure 11-4. The 2013 total future traffic forecasts with the movie theater alternative were developed using the 2013 background forecasts shown on Figure 4-10 and the site trip assignments shown on Figures 11-3. The resulting movie theater alternative traffic forecasts are shown on Figure 11-5. OPERATIONAL ANALYSIS Future peak hour levels of service, with the two alternatives, were determined at the key study intersections and driveways based on the total future traffic forecasts shown on Figures 11-4 and 11-5, the future lane use and traffic control

71

Tab

le 1

1-1

Cos

tco

Who

lesa

le -

Ale

xand

ria/

Mou

nt V

erno

nA

ltern

ativ

e T

rip

Gen

erat

ion

Ana

lysi

s

Wee

kday

Satu

rday

Scen

ario

Land

Use

PM P

eak

Hou

rSa

t Pe

ak H

our

Ave

rage

Ave

rage

Cod

eA

mou

ntU

nits

InO

utT

otal

InO

utT

otal

Dai

ly T

rips

Dai

ly T

rips

Alt

erna

tive

1

Gen

eral

Ret

ail (

11.8

8 ac

res

@ 0

.5 F

AR

)82

025

8,74

6SF

589

614

1,20

382

776

31,

590

12,5

9816

,818

Pass

-by

Trip

s25

%(1

47)

(154

)(3

01)

(207

)(1

91)

(398

)(3

,150

)(4

,205

)

Tot

al N

ew G

ener

al R

etai

l Tri

ps44

246

090

262

057

21,

192

9,44

812

,613

Alt

erna

tive

2

Mul

tiple

x M

ovie

The

ater

(w

ith S

quar

e Fo

otag

e)(2

)44

552

,399

SF15

998

257

206

6827

4n/

an/

a

Tot

al M

ulti

plex

Mov

ie T

heat

er T

rips

159

9825

720

668

274

n/a

n/a

Not

e(s)

:

(1)

Tri

p ge

nera

tion

base

d on

the

Inst

itute

of T

rans

port

atio

n En

gine

ers'

Tri

p G

ener

atio

n , 8

th E

ditio

n.

(2)

Tri

p ge

nera

tion

for

the

PM p

eak

hour

is b

ased

on

a Fr

iday

as

no "

typi

cal"

wee

kday

dat

a w

as a

vaila

ble

in t

he IT

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Highway

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Highway

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6

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77



shown on Figure 6-2, and the Highway Capacity Manual methodology. The Synchro results for the 2013 alternative future conditions are presented in Appendix U and summarized in Table 11-2. The results are also shown on Figures 11-6 and 11-7. The results of the future conditions with the proposed development indicate the following: Retail Alternative

1. Under the 2013 future conditions with the

retail alternative, at each of the signalized intersections, a majority of the side street movements and the mainline left-turn movements would continue to operate at capacity consistent with the conditions without the development.

2. The Richmond Highway/Sherwood Hall Lane/Wal-Mart Driveway intersection would operate at overall LOS “F” during both of the peak periods.

3. The Richmond Highway/Mount Vernon

Highway/Buckman Road intersection would operate at overall LOS “F” during the Saturday peak period.

4. The southbound approach at the Costco

entrance on Ladson Lane would operate at capacity during both peak periods.

Movie Theater Alternative 1. The Richmond Highway/Sherwood Hall

Lane/Wal-Mart Driveway intersection would operate at overall LOS “F” during the PM peak period and LOS “E” during the Saturday midday peak period.

2. The Richmond Highway/Mount Vernon Highway/Buckman Road intersection would operate at overall LOS “E” during the Saturday peak period.

3. All other critical movements at each of the STOP controlled intersections would operate at an acceptable LOS “D” or better during the PM and Saturday peak periods, with an exception of the southbound left movement at the Richmond Highway/ Apartment Driveway intersection.

Summary. The results indicate that the general by-right retail alternative at a 0.50 FAR would impact the area road network with greater delays and greater vehicle-queues than the proposed Costco Wholesale store or former movie theater use. The retail alternative would generate approximately 595 more weekday PM peak hour trips, 608 more Saturday peak hour trips, and 6,603 more weekday daily trips than the proposed Costco Wholesale store. Additional improvements beyond those proposed with this application would be required to further mitigate the retail alternative. These improvements would likely require implementation of the planned widening to US Route 1 with turn lane improvements.

78


Levels of Service with Alternative Developments (1) (2) (3)


(1) Richmond Highway (Route 1)/ Signal EBL F (84.7) F (103.3) F (97.9) F (121.6) F (80.2) F (88.8)Sherwood Hall Lane/ EBT E (72.1) E (70.2) E (72.5) E (70.6) E (72.0) E (70.1)Wal-Mart Driveway EBR E (75.0) E (68.1) E (74.5) E (67.9) E (75.4) E (68.7)


NBTR F (158.3) F (115.3) F (177.5) F (127.3) F (147.4) F (90.4)SBL E (74.9) F (112.4) E (74.9) F (112.4) E (74.9) F (109.4)SBT E (69.8) D (46.0) F (80.4) D (49.6) E (66.8) D (42.9)SBR C (23.8) C (23.3) C (23.8) C (23.3) C (23.7) C (22.6)

Overall F (113.2) F (87.5) F (127.4) F (96.5) F (106.7) E (74.2)

(2) Richmond Highway (Route 1)/ STOP EBR B [13.5] B [13.6] C [15.9] C [16.8] B [12.3] B [11.3]Site Driveway

(3) Richmond Highway (Route 1)/ STOP WBLR B [13.8] C [19.6] B [14.6] C [18.6] B [13.1] C [18.4]Apartment Driveway SBL D [33.3] E [40.9] E [36.8] E [44.3] D [31.4] E [35.7]


NBL E (74.2) F (140.2) F (210.6) F (414.4) E (73.7) E (73.3)NBT B (10.6) A (6.7) B (11.3) A (8.0) B (10.9) A (6.6)SBTR E (69.5) C (26.2) F (92.6) C (32.5) C (26.8) B (15.8)

Overall D (45.3) C (27.3) E (65.8) E (56.6) C (22.8) B (15.7)


WBR F (100.6) F (412.2) F (128.7) F (479.2) F (96.3) F (367.0)NBL C (31.2) C (28.9) D (35.3) C (29.4) C (29.4) C (28.1)

NBTR E (56.5) D (52.9) E (70.7) E (56.0) D (53.1) D (51.5)SBL E (79.8) F (133.1) E (79.4) F (143.4) E (79.3) F (113.9)SBT A (9.0) B (12.1) B (11.7) B (12.3) A (7.9) B (11.0)SBR A (8.7) A (9.9) A (8.1) A (8.2) A (8.2) B (12.4)

Overall D (41.1) F (84.3) D (48.7) F (93.8) D (39.3) E (77.9)

(6) Site Entrance/ STOP EBLT A [0.8] A [1.3] A [1.1] A [1.6] A [0.7] A [1.0]Ladson Lane SBL/SBLR C [19.4] E [36.8] F [92.4] F [217.4] B [13.3] B [12.3]

SBR N/A N/A N/A N/A N/A N/A



Notes:




2013 Total Future

(Proposed Costco at 0.27 FAR)

2013 Total Future

(Potential 0.5 FAR Retail)

2013 Total Future

(Existing Theater at 0.10 FAR)


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SECTION 12 CONCLUSIONS AND RECOMMENDATIONS PRINCIPAL FINDINGS The conclusions of this study are as follows:

1. The results of the existing analyses indicate

that the Richmond Highway/Ladson Lane signalized intersection currently operates at an overall acceptable level of service during all peak periods. The Richmond Highway/Sherwood Hall Lane/Wal-Mart Driveway and Richmond Highway/Mount Vernon Highway/Buckman Road intersections operate near capacity. All of the approaches at the stop controlled intersections currently operate at acceptable levels of service.

2. Background traffic from two (2) pipeline developments (BRAC and Mount Vernon Gateway) would add new trips to the road network. BRAC would generate regional trips and Mount Vernon Gateway would generate local trips in the study area.

3. The results for the background capacity

analyses (without the proposed uses) for the year 2013 indicate overall consistent levels of service when compared to existing conditions with minor increases in delay as a result of regional traffic growth and pipeline developments.

4. Under 2019 conditions without the

development, the individual lane groups at each of the three (3) signalized intersections on Richmond Highway would continue to operate at, or near capacity, similar to existing conditions but with higher delays.

5. Costco Wholesale proposes to raze an existing closed theatre and construct a 143,416 GSF retail discount store. This new retail store is expected to add a total of 456 new PM peak hour trips and 737 new peak hour trips on Saturday, when fully constructed and occupied. This proposal would add 4,496 new daily (24-hour) trips on weekdays.

6. The results for the total future analyses

(with the proposed uses) indicate similar delays to those identified under background conditions with slight increases. The vehicle queue at the northbound left-turn lane on Richmond Highway at Ladson Lane would exceed the available turn lane storage.

7. Intersection lane use and signal phasing improvements at all three (3) signalized intersections on Richmond Highway would improve levels of service and reduce vehicle queues. The vehicle queue at the northbound left-turn lane on Richmond Highway at Ladson Lane would reduce with signal improvements but continue to exceed the available turn lane storage.

8. A traffic control sign indicating “Right-turns yield to U-turning vehicles” should be installed at the eastbound right-turn lane on Ladson Lane at the Richmond Highway/Ladson Lane intersection to mitigate the existing “U-Turn” conflict with the eastbound overlap right-turn movement from Ladson Lane.

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9. The results for the 2019 future analyses with the development indicate similar delays to those identified under 2019 future analysis without development with the exception of Richmond Highway/Mount Vernon Highway/Buckman Road intersection that would operate at overall theoretical capacity during Saturday peak hour.

10. The 2013 future analysis with by-right retail alternative indicates that the signalized intersections of Richmond Highway/Sherwood Hall Lane/Wal-Mart Driveway and Richmond Highway/Mount Vernon Highway/Buckman Road would operate at overall levels of service consistent with the 2013 future analysis with proposed development except with higher delays during the PM and Saturday peak hours.

11. Under 2013 by-right retail alternative, the signalized intersection of Richmond Highway/Ladson Lane and certain critical movements at the STOP controlled intersection of Ladson Lane and Site Entrance would however operate at theoretical capacity during the PM and Saturday peak hours.

12. The 2013 future analysis with the existing

movie theater as operational indicates that each of the study intersections would operate at levels of service consistent with the 2013 future analysis with proposed development except with lower delays during the PM and Saturday peak hours.

13. The alternative analysis indicates that the

proposed development is less intensive use than a by-right retail use. Additionally, the proposed new Costco development would not have a significantly higher impact than an operational movie theater located on the subject site.

RECOMMENDATIONS The following improvements should be completed by the Applicant to offset the impact of the proposed new Costco Wholesale: 1. Modification of the signal timing splits at the

Richmond Highway/Ladson Lane intersection to provide additional green time for heavier turn movements. Modification of the signal timing splits at the Richmond Highway/Sherwood Hall Lane/Wal-Mart Driveway intersection. Modification of the signal timing splits at the Richmond Highway/Buckman Road/Mount Vernon Highway intersection.

2. Construction of an exclusive southbound

right-turn lane at the Richmond Highway/Ladson Lane intersection.

3. Construction of an exclusive westbound

right-turn lane at the Ladson Lane/Site Entrance intersection.

4. Closure of the existing median break at the

intersection of Richmond Highway and entrance to the Spring Garden Apartments.

5. Extension of the existing northbound left-


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Documents

Costco Transportation Impact Analysis