FEASIBILITY REPORT 3.2 HOV CONNECTOR RAMP …media.metro.net/projects_studies/I605/605_03_part2.pdf · FEASIBILITY REPORT Page 38 Metro and GCCOG SR-91/I-605/I-405 Congestion Hot

FEASIBILITY REPORT

Page 38 Metro and GCCOG SR-91/I-605/I-405 Congestion Hot Spots

3.2 HOV CONNECTOR RAMP IMPROVEMENT CONCEPTS

An analysis was performed to assess the performance of a potential SR-91/I-605/I-105 HOV connector system, using data from the Gateway Cities SR-91/I-605/I-405 project travel demand model. The system was reviewed at the following locations:

SR-91 to I-605

I-605 to I-105

I-605 to SR-60 Traffic model runs were developed to assess how these HOV connector ramps would operate. Based on those results the following HOV connector locations were evaluated further with conceptual geometric plans:

WB SR-91 to NB I-605

SB I-605 to EB SR-91

NB I-605 to WB I-105

EB -105 to SB I-605

NB I-605 to EB SR-60

WB SR-60 to SB I-605 The HOV connector ramps at the SR-91/I-605/I-105 location can be generally described as follows:

SR-91 widens out to a 4 lane HOV in the vicinity of Pioneer to allow for start of elevated connector

A 2 lane connector elevates from SR-91 to I-605

I-605 widens out to a four lane HOV in the Alondra vicinity to allow for the 2 lane connector join

I-605 is 4 lane HOV up to elevated 2 lane connector in the Rosecrans/105 area to allow for weaving for 605/105 HOV

A 2 lane connector elevates from I-605 to I-105

I-105 widens out to a 4 lane HOV to allow for I-105 connector join.

I-105 4 lane HOV merges to existing 2 lane HOV (if it was an HOT facility then it would continue as a 4 lane HOT rather than merging – for the purpose of this Feasibility Report at this time it was only evaluated as an HOV).

The system allows for vehicles to connect directly between I-105 and SR-91 via I-605. This system would provide for operational efficiencies by improving operational bottleneck issues at the SR-91/I-605 and I-605/I-105 interchanges by reducing mainline general purpose ramp connector volumes and shifting volume into the HOV system. Weaving between the HOV lane on SR-91 east of I-605 and the mainline connector ramps would be eliminated for HOV traffic. Likewise, weaving on I-105 between the HOV lanes and the mainline connector ramps for

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activity to and from the south would be eliminated from the mainline and connector ramps. Weaving activity currently degrades peak period operations of the SR-91, I-605 and I-105 facilities. The HOV system identified above would provide for a direct connection for HOV activity between the heart of Orange County and Downtown Los Angeles. Existing connectors between I-5 to SR-91 and I-110 and I-105 would indicate that the HOV system between SR-91, I-605 and I-105 may be a logical component to close the gap in the regional HOV system network. Table 13 presents 2035 HOV and total vehicle volumes that are forecast to utilize the existing general purpose lane freeway to freeway connectors under future year No-Build project conditions. A key conclusion from the data presented in the table is that the HOV demand between I-605 and I-105 is much higher than HOV demand between I-605 and SR-91 (approximately two times higher HOV peak period volumes projected between I-605/I-105 than I-605/SR-91). HOV volumes that are forecast to use the existing mainline connectors under 2035 conditions reach up to approximately 45% of the mainline connector volumes between I-605 and I-105. The highest evening peak hour HOV volume forecast on the connectors is 1,200 vehicles, close to the maximum allowable connector volume of 1,500 for a 2-lane connector (1-lane each direction). While 100% of this volume may not be able to utilize the HOV system due to specific travel patterns and the potential that the HOV system will not serve a local interchange that users must access, the inference can be made that a large proportion of the HOV traffic on these connectors is likely to shift into an HOV system if it is implemented. The evening peak hour HOV volumes at SR-91 range from approximately 400 to 600 vehicles. Based on the future No-Build forecasts, it may be difficult to justify the connector at SR-91 due to potential underutilization of these particular HOV connectors. However, implementation of the connectors may increase demand for the overall HOV system, thereby increasing the HOV activity between SR-91 and I-605.

TABLE 13: FUTURE FORECAST 2035 CONNECTOR PEAK HOUR TRAFFIC DEMAND

Connector AM Peak Hour PM Peak Hour

HOV Total % HOV HOV Total % HOV

I-605 SB to SR-91 EB 350 1,400 25% 400 1,400 29%

SR-91 WB to I-605 NB 200 1,500 14% 600 1,800 33%

I-605 NB to I-105 WB 600 2,400 26% 1,100 2,500 44%

I-105 EB to I-605 SB 1,050 2,700 39% 1,200 2,900 42%

Allowing at-grade access from I-605 into the elevated HOV connector structures to both SR-91 and I-105 further increases local and regional mobility and expands the market of users for the HOV system. The at-grade access on I-605 between I-105 and SR-91 also provides direct HOV system access from coastal Orange County communities to Downtown Los Angles with the HOV connectors soon to be completed at I-405 and I-605. Table 13 reveals that HOV demand exists

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on the I-605 corridor that does not necessarily come from the SR-91 corridor (as noted the HOV volumes are much higher at I-105 than at SR-91). During the morning peak hour, approximately 200 HOV vehicles are forecast on the SR-91 westbound to I-605 northbound connector while the subsequent connection from I-605 northbound to I-105 westbound is approximately 600 vehicles. It is unlikely many of the 600 vehicles access the I-605 corridor from SR-91 west of I-605 as these vehicles would be backtracking if they then take the I-605 connector to westbound I-105. Therefore, while some of the 600 HOV vehicles using the I-605 northbound to I-105 westbound connector come from SR-91 east of I-605, many come from I-605 south of SR-91. This could be due to the new I-605 HOV connection with I-405 that the travel demand model takes into consideration. Central Orange County HOV users likely are forecast to take the I-5 corridor to Downtown Los Angeles since a comprehensive HOV network between Orange County and Downtown Los Angeles does not exist. Implementation of the full HOV system by connecting SR-91 with I-105 via the HOV system would likely pull demand from other corridors (notably I-5) onto this system thereby improving local and regional traffic operations. As noted, consideration must be given to the fact that if such an HOV system were implemented connecting SR-91 and I-105, additional traffic demand would be attracted to the facility due to the regional connectivity provided by a comprehensive HOV system connecting Orange County with Downtown Los Angeles. In addition, as congestion increases region-wide, additional carpools are likely to be formed and with continued job growth in Downtown Los Angeles, access to downtown will continue to increase. An HOV system that provides a more reliable commute travel time should attract additional users. This HOV analysis is based on a general assessment utilizing available data from the SR-91/I-605/I-405 travel demand model. More precise modeling techniques utilizing select link analysis would be required in a subsequent project development phase to better assess the HOV volumes that may be realized, along with appropriate HOV connector movements. In addition, a previous Technical Memo prepared by the SR-91/I-605/I-405 Consultant Team for a conceptual evaluation of HOT lane facilities in the area also provided key conceptual findings that would also need to be jointly taken into consideration from a technical, as well as a policy, standpoint. Traffic model runs or analysis were not performed for the potential I-605 to SR-60 HOV connector ramps. The geometric plan was prepared to show how this pair of HOV connector ramps would fit in with the proposed other improvements to the SR-60/I-605 interchange. Decisions whether to build this pair of HOV connector ramps is a regional decision to be evaluated and made by other agencies. Conceptual geometric plans were prepared for HOV connectors for three scenarios: SR-91/I-605/I-105, I-605/I-105 and I-605/SR-60. These plans are presented in Appendix F. These concepts were prepared to illustrate impacts to right of way relative to creating a wider geometric footprint for accommodating the potential HOV connectors. These connectors are not included as part of the traffic analysis and geometric plans for Concepts A, B and C. Further study of the HOV connectors will be evaluated in the subsequent project development phase.

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3.3 I-105/ALAMEDA STREET IMPROVEMENT CONCEPT

The City of Compton views Alameda Street as a critical entry arterial into the city from I-105. To enhance direct access to the downtown city area, the City of Compton requested the Project Team develop a full service interchange concept at Alameda Street and I-105. The concept plan is provided in Appendix G. Traffic analyses were not performed for this concept at this time.

3.4 COST ESTIMATES FOR FREEWAY IMPROVEMENT CONCEPTS

Cost Estimating Methodology for Freeway Improvements

A lane-mile cost estimating methodology for freeway improvements has been developed and will serve as the basis for the preparation of project cost estimates for the Feasibility Report. The lane-mile cost estimate includes all costs related to construction, right of way, utilities, project support, and contingencies. The lane-mile cost estimate methodology was based upon an analysis of freeway project bid tabulation data from the years 2006 through 2012. A key assumption is that the freeway project bid tabulation data captures all construction costs associated with the widening of a freeway (structure widening, retaining walls, sound walls, signs, drainage improvements, ITS, etc). Costs for utilities, project support, and contingencies were established as a percentage of the lane-mile construction cost estimate. The percentages are also based upon historical project cost data. Costs for right of way are based on recent land valuations in the project boundary area.

The following procedure was applied:

Freeway Project Cost Data Research

1. From the Caltrans web site:

http://www.dot.ca.gov/hq/esc/oe/planholders/awarded_csv.php

a list of freeway improvement projects in Caltrans Districts 7 and 12 from years 2006 – 2012 was developed:

EA Contract No. 12-0F0314 - Northbound SR-57 from Orangethorpe Avenue to Yorba Linda Blvd. (PM 16.2 to PM 18.8)

EA Contract No. 12-0F0324 - Northbound SR-57 from Yorba Linda Blvd. to Lambert Road (PM 18.4 to PM 20.9)

EA Contract No. 12-071624 - Northbound and Southbound I-405 from Bolsa Chica Road to Seal Beach Blvd. (PM 20.4 to PM 22.3); and Westbound and Northbound SR-22 from Bolsa Chica Road to SR-22/I-405 Separation (PM R0.7 to PM R2.9)

EA Contract No. 12-071634 - Northbound and Southbound I-405 from Seal Beach Blvd. to I-605/I-405 Separation (PM 22.3 to PM 24.0); Southbound I-605 from I-405/I-605 Separation to Los Angeles County Line (PM 3.0 to PM R1.6); and from SR-22/I-605 Separation to SR-22/I-405 Separation (PM R0.3 to PM R0.9)

http://www.dot.ca.gov/hq/esc/oe/planholders/awarded_csv.php

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EA Contract No. 12-071674 - Northbound I-5 and Southbound I-5 from Orangethorpe Avenue to Artesia Avenue (PM 42.1 to PM 44.4

EA Contract No. 12-0G0404 - Eastbound SR-91 from SR-91/SR-241 Separation to SR-91/SR-71 Separation (PM 15.9 to PM 18.9)

EA Contract No. 12-0G3304 - Eastbound SR-91 and Westbound SR-91 from SR-55/SR-91 Separation to SR-91/SR-241 Separation (PM 9.1 to PM 15.1)

EA Contract No. 07-121844 - Northbound I-5 and Southbound I-5 from I-5/SR-134 Separation Magnolia Blvd. (PM 26.7 to PM 29.4)

EA Contract No. 07-1218V4 - Northbound I-5 and Southbound I-5 from Cohasset Street to Sheldon Street (PM 31.6 to PM 36.0)

EA Contract No. 07-1219U4 - Northbound and Southbound I-405 from Sheldon Street to I-5/SR-118 Separation (PM 36.0 to PM 39.4); and Northbound and Southbound SR-170 from Arleta Ave./Sheldon St. to I-5/SR-170 Separation (PM 32.3 to PM 33.1)

EA Contract No. 07-215934 - Northbound I-5 and Southbound I-5 from Carmenita Road to Silverbow Avenue (PM 2.4 to PM 4.0)

EA Contract No. 07-215944 - Northbound I-5 and Southbound I-5 from San Antonio Drive to Pioneer Blvd. (PM 4.0 to PM 5.9)

2. From the Draft Project Report, prepared by Parsons Transportation Group dated May 7, 2012:

EA Contract No. 12-OH1000 (Alternative 1) - Northbound I-405 and Southbound I-405 from Euclid Street to I-605 (PM 12.1 to PM 23.9, PM R0.6 to PM R0.7, PM R0.7 to PM R1.0)

EA Contract No. 12-OH1000 (Alternative 2) - Northbound I-405 and Southbound I-405 from Euclid Street to I-605 (PM 12.1 to PM 23.9, PM R0.6 to PM R0.7, PM R0.7 to PM R1.0)

3. Project bid summaries were obtained from:

http://www.dot.ca.gov/hq/esc/oe/planholders/bidsum.php

4. Project plans were obtained from:

http://www.dot.ca.gov/hq/esc/oe/project_ads_addenda/

5. Project plans were reviewed to confirm that the project scope is comparable to the SR-91/I-605/I-405 Corridor freeway improvement projects and that the application of the project cost data is appropriate.

http://www.dot.ca.gov/hq/esc/oe/planholders/bidsum.php

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Freeway Project Bid Tabulation/Cost Estimate Evaluation

Bid tabulations were evaluated as follows:

1. A total of (14) freeway widening projects were evaluated.

2. Established overall project length & general scope of work.

3. Determined length of new mainline lanes provided.

4. Determined high bid, low bid and engineer’s estimate.

5. Calculated overall average cost per lane mile for new mainline lane (with bridge structural costs excluded) based on the average of the high bid, low bid and engineer’s estimate.

6. Utilized the Draft Project Report Cost Estimate for Alternative I (1 new lane each way on I-405) and Alternative 2 (2 new lanes each way on I-405) for the I-405 widening project currently in the environmental phase by OCTA. To maintain consistency in the use of this cost data for comparative purpose with actual construction bid data, the contingency and supplemental work dollar amounts shown in the Draft Project Report Cost Estimate were removed.

Lane-mile Cost Estimate Determination

The per mainline lane-mile cost was determined through the following steps:

1. Construction bids or engineer’s estimates for the (14) projects ranged from $28M to $807M and per lane-mile costs ranged from $6.0M to $16.4M

2. Average lane-mile cost was derived from the following analysis:

An average of all projects listed, except I-5 Gateway (EA 12-101674) and I-405 PR (EA 12-0H1000) = $8.5M.

An average of all projects listed, except I-5 Gateway (EA 12-101674); I-405 PR (EA 12-0H1000); I-405/I-605 West County Connectors (EA 12-071624 and EA 12-071634); and I-5/SR-118/SR-170 (EA 07-1219U4) = $7.6M.

An average of all projects listed, except I-5 Gateway (EA 12-101674) and I-405 PR (EA 12-0H1000, Alt 1) = $8.7M.

An average of all projects listed, except I-5 Gateway (EA 12-101674) = $9.2M.

Average of these four scenarios is $8.5M/lane-mile.

The I-5 Gateway was excluded from the four average scenarios due to the significant costs for "Boat Section" construction and peak high market bid climate at the time of bidding in 2006.

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All comparisons of per lane-mile costs include arterial interchange ramps, as well as arterial street modifications that may have been required due to the freeway construction.

3. Conclusion: Table 14 reflects the results of the lane-mile cost determination. All of the bid tabulation projects included significant quantities of retaining walls and sound walls and included modifications of both bridge structures and interchanges, which makes for a strong correlation for the SR-91/I-605/I-405 corridor freeway projects. For this project, a cost of $8.5M per mainline lane-mile will be used, inclusive of ramp alignments and minor arterial street modifications. System interchange connector ramps are estimated at approximately 50% of the mainline lane-mile cost utilizing a $4.0M lane-mile cost.

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TABLE 14: HISTORICAL BID/ESTIMATE PROJECT COST COMPARISONS

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TABLE 14 (CONT.): HISTORICAL BID/ESTIMATE PROJECT COST COMPARISONS

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TABLE 14 (CONT.): HISTORICAL BID/ESTIMATE PROJECT COST COMPARISONS

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Mainline and Ramp Cost Estimate Development

Appendix I represent the detailed breakdown of costs for Concepts A, B, and C and also serve as the basis for defining cost ranges associated with individual, or segment, congestion hot spot areas. Table 15 at the end of this section presents a Summary of Costs for Concepts A, B and C.

The primary cost per mainline lane-mile of $8.5 M is generally inclusive of arterial interchange on/off ramps and minor arterial street modifications that are typically associated with mainline widening and ramp reconstruction. For more significant arterial street modifications associated with the freeway widening lane (e.g. Bellflower, Downey, Paramount and Cherry) lane-mile distances were added to the total freeway mainline lane distance to account for this cost. There are certain locations, within Concept A, B, or C, that contain CD Roads or longer braided ramps that parallel the freeway for some distance. At these locations an additional number of “equivalent” mainline lanes, representing the CD Roads and longer braided ramps are added to the actual number of mainline lanes.

Connector ramps for system interchanges are quantified by lane-miles separately from the mainline lanes. The number of lanes typically varies throughout a connector ramp’s length, thus a designation of the number of lanes (e.g. 1, 2, 3 etc.) was applied to derive an equivalent lane-mile value.

Bridge, Right of Way and Utility Cost Estimate Development

1. Bridge structure costs were evaluated based on the type of modification and calculated separate from the mainline lane-mile costs on a $/SF basis.

2. Right of way costs were evaluated based on land use/square footage of acquisition and quantified separately. Per square foot acquisition costs were established for various classifications of acquisition (e.g. residential, commercial, park, etc.) and based upon recent land valuations in the project boundary area.

3. Major utilities were calculated based on 5% of the total estimated construction costs, inclusive of the 30% contingency.

Contingencies

1. Caltrans guidance for appropriate percentages to be used for contingencies was reviewed and a 30% contingency applied to capital construction cost and right of way cost.

Project Support Cost Calculation

Project support costs were estimated as a percentage of the total construction cost or total right of way cost, and consist of the following elements:

1. Project Study Report (PSR): 2.5% of total estimated construction cost with 30% capital construction contingency

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2. Project Approval / Environmental Document (PA/ED): 5% of total estimated construction cost with 30% capital construction contingency

3. Plans, Specifications & Estimate (PS&E): 12% of total estimated construction cost with 30% capital construction contingency

4. Construction Management and Inspection (CM): 15% of total estimated construction cost with 30% capital construction contingency

5. Public Awareness/Outreach (PAC): 1% of total estimated construction cost with 30% capital construction contingency

6. LAMTA Project Management: 2% of total estimated construction cost with 30% capital construction contingency

7. Right of Way Support: 35% of total estimated right of way capital cost with 30% right of way capital contingency

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TABLE 15: FREEWAY CONGESTION HOT SPOTS COST ESTIMATE SUMMARIES

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FEASIBILITY REPORT 3.2 HOV CONNECTOR RAMP …media.metro.net/projects_studies/I605/605_03_part2.pdf · FEASIBILITY REPORT Page 38 Metro and GCCOG SR-91/I-605/I-405 Congestion Hot