Appendix E: VISSIM Model Calibration Summary · VISSIM (Version 9, Build 10) was used to develop the AM and PM existing conditions models of the Rosslyn transportation network. Vehicle,

Core of Rosslyn Transportation StudyExisting Conditions Report - Appendix

Appendix E: VISSIM Model Calibration Summary

Core of Rosslyn Transportation StudyVISSIM Model Calibration Summary 05.09.2018

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VISSIM Model Calibration SummaryIntroduction and PurposeThe following document details the procedures and assumptions used to develop and calibrate the AMand PM Existing Conditions VISSIM models for the Rosslyn Street Reconfiguration ImplementationStudy. The calibration process follows the guidance from the Virginia Department of Transportation(VDOT) Traffic Operations and Safety Analysis Manual (TOSAM) Version 1.

VISSIM (Version 9, Build 10) was used to develop the AM and PM existing conditions models of theRosslyn transportation network. Vehicle, transit, pedestrian, and bicycle modes were included in themodels. The VISSIM models were calibrated to real world conditions, as documented or observed usinga variety of field data sources. A separate data collection summary document has been prepared andcontains information on the existing conditions data used to calibrate the models.

The objective of calibration was to develop models that reasonably reflect existing multimodal trafficoperations in the Rosslyn study area. A calibrated set of models will be the basis for evaluation futureroadway and multimodal improvements.

Characteristics of the VISSIM Study AreaThe study area modeled in VISSIM consists of the N. Lynn Street and Fort Myer Drive corridors, plus oneadjacent intersection on each side of the corridor. Freeway mainline segments and ramps that provideaccess to the arterial network are also included (I-66, Arlington Boulevard, and Route 110). Figure 1shows the VISSIM study area.


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Figure 1. VISSIM Study Area

A four-hour simulation period was selected to capture the onset and dissipation of study areacongestion. This consists of a one-hour seeding period, a two-hour peak period, and a one-hourshoulder period. The AM and PM peak hours span the middle hour of the two-hour peak period. Table 1summarizes the simulation periods and Figure 2 shows the total network intersection volume profilesthat were used to determine the simulation periods.

Table 1. VISSIM Simulation Periods

Seeding Period Peak Hour VISSIM PeakPeriod Shoulder Period

AM 6:30 to 7:30 AM 8:00 to 9:00 AM 7:30 to 9:30 AM 9:30 to 10:30 AMPM 3:30 to 4:30 PM 5:00 to 6:00 PM 4:30 to 6:30 PM 6:30 to 7:30 PM


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Figure 2. VISSIM Simulation Periods and Total Intersection Volume Profiles

AM Peak Period ConditionsThe AM peak period operates under congested conditions and is characterized by:

· Queuing along N. Lynn Street from Key Bridge back to Arlington Boulevard; congestion on KeyBridge also creates queues onto westbound I-66 (Exit 73) off-ramp

· Queuing and slow-moving platoons along eastbound Lee Highway, from the intersection with N.Lynn Street, spilling back to N. Rhodes Street

· Significant traffic flow, vehicle interactions, and queuing from multiple approaches at thenorthern and southern termini of N. Lynn Street and Fort Myer Drive corridors

· Queuing and slow-moving platoons along eastbound Clarendon Boulevard into the study area,spilling back to N. Rhodes Street

· Queuing on eastbound Key Boulevard and eastbound Arlington Boulevard (frontage road) dueto preponderance of cut-through traffic

· Queuing along eastbound Arlington Boulevard back to the 10th Street interchange from theTheodore Roosevelt Bridge, causing spillback onto N. Meade Street from the on-ramp

· Queuing and slow-moving platoons along eastbound I-66 from eastern end of TheodoreRoosevelt Bridge

· Significant transit activity along N. Moore Street and 19th Street N.· Significant pedestrian activity throughout the study area, delaying right-turns at intersections

and garage entrances

PM Peak Period ConditionsThe PM peak period operates under congested conditions and is characterized by:

0

2,000

4,000

6,000

8,000

10,000

12,000

TOTA

LIN

TERS

ECTI

ON

VOLU

ME

AM SIMULATION PERIODPEAK PERIOD

PEAK

HOU

R

SHO

ULD

ERHO

UR

SEED

ING

HOU

R

PM SIMULATION PERIODPEAK PERIOD

PEAK

HOU

R

SHO

ULD

ERHO

UR

SEED

ING

HOU

R


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· Queuing along N. Lynn Street from Key Bridge back to 19th Street N; congestion on Key Bridgealso creates queues onto westbound I-66 (Exit 73) off-ramp

· Queuing along eastbound I-66 and Lee Highway from the weave between the on-ramp fromeastbound Lee Highway and the off-ramp to Route 110

· Queuing along westbound Wilson Boulevard in the study area· Reduced speeds and weaving issues along Fort Myer Drive approaching Arlington Boulevard· Significant pedestrian activity throughout the study area

VISSIM Network DevelopmentRoadway GeometryThe VISSIM model files created as part of VDOT’s Transform 66 – Inside the Beltway project were usedas base files for the development of the Rosslyn model. The network roadway geometry was updatedfrom the VDOT models, based on aerial imagery and verified with field observations, to better representthe Rosslyn study area network.

The updated geometry and network represents roadway configuration as of November 2017. As such,the following tactical urbanism or police enforcement strategies are included in the existing conditionsmodels:

· Restriping of southern leg of Fort Myer Drive and 19th Street N.· Restriping of southern leg of Fort Myer Drive and eastbound Lee Highway· Restriping and bicycle lane on N. Lynn Street between 19th Street N. and eastbound Lee Highway· Prohibition of westbound right-turns from Wilson Boulevard to N. Lynn Street· Prohibition of southbound left-turns from N. Moore Street to Wilson Boulevard

AM and PM model geometry is consistent, with the exception of the reversible lane operation onTheodore Roosevelt Bridge which was uniquely coded for each peak period. The bridge has foureastbound lanes and three westbound lanes in the AM, while in the PM, the bridge has three eastboundlanes and four westbound lanes.

Speed DistributionsDesired speed distributions, or model free-flow speeds, were set based on posted speed limits and thefollowing guidance provided by TOSAM:

· From 5 miles per hour (mph) below the posted speed limit to 5 mph above the posted speedlimit for arterials

· From 3 mph below the posted speed limit to 10 mph above the posted speed limit for freeways· From 7.5 mph to 15.5 mph for right turns and from 12.4 mph to 18.6 mph for left turns

Ramp speed distributions are referenced from posted advisory speeds.

Traffic Control DevicesA total of 19 signalized intersections were modeled using ring barrier controllers (RBCs). Signal timingswere based on Synchro models and timing sheets provided by Arlington County.


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Vehicle RoutingVehicular routing was coded as complete origin-destination vehicle routing decisions between networkentry and exit locations. The process in Figure 3 was used to develop vehicle routing based on peakperiod trip tables that were validated as part of travel demand modeling.

Figure 3. VISSIM Vehicle Routing Development

Vehicle CompositionsThree vehicle classes were used in the VISSIM models: cars, small trucks, and heavy trucks. Uniformvehicle compositions were set network-wide based on vehicle classification data provided by ArlingtonCounty for locations near the study area. Table 2 summarizes the vehicle compositions used in the AMand PM models. The heavy vehicle compositions were set to zero for network inputs on I-66, GeorgeWashington Memorial Parkway, and parking garages because of truck prohibitions. In addition, buseswere excluded from the vehicle compositions so that bus operations could be modeled explicitly byroute and schedule as discussed in a later section.

Table 2. VISSIM Vehicle Compositions

Vehicle Class Composition Example Vehicle TypesCar 92.5% Passenger Cars, Pickup Trucks, Vans

Small Truck 7.0% Single Unit TrucksHeavy Truck 0.5% Single Trailer Trucks

Vehicle Input DistributionVehicle inputs were coded in 15-minute intervals to reflect variations in traffic volumes across the peakperiods. Localized input distributions were created for each network entry point using raw traffic countsthat were adjusted to balanced peak hour volumes. The distribution factors represent the flow rate for a15-minute interval in relation to the volume for the network peak hour at that location. The localizedvehicle input distributions allow peaking to occur at different locations at different times as observed inthe field while still inputting the proper volume for the network peak hour (i.e., the basis for volumecalibration).

Import TripTablesVISSIM

•VISUM trip tablesimported intoVISSIM to createvehicle routingdecisions

•Consistency checkbetween VISSIMand VISUM

VISSIM AreaSubnetworkGeneration

VISUM

•Roadway linkscontained in theVISSIM networkareas extracted asVISUM subnetwork

•Subnetwork O-Dmatrix correction

RosslynSubarea

Peak HourTrip Tables

VISUM

•O-D Matrixcorrection usingVISUM TFlowFuzzyto matchassignment to peakhour turningmovement and linkcounts

RosslynSubarea

Peak PeriodTrip Tables

VISUM

•Ratio of peakperiod to peak hournetwork trafficcounts used asscalar

•0.444 for AM•0.288 for PM


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Public TransitBus routes and stops in the VISSIM network area were coded using posted maps and schedules. Routesincluded in the models are shown in Table 3. Bus stop dwell times were set using a normal distributionwith a mean of 20 seconds and standard deviation of 10 seconds.

Table 3. Bus Routes Included in VISSIM Models

Operator Bus RouteArlington Transit 43, 45, 55, 61A, 61B

Metrobus 3Y, 4A, 4B, 5A, 10E, 38B

Loudoun CountyTransit

Dulles North – Pentagon,Dulles North – State Dept.,

Purcellville – Pentagon,Purcellville – State Dept.

Potomac andRappahannockTransportation

Commission(PRTC)

Dale City - Pentagon/Rosslyn/Ballston,Gainesville-Washington,

Gainesville-Pentagon,Manassas-Pentagon,

Manassas-WashingtonFairfax Connector 599, 699

DC Circulator Dupont Circle - Georgetown - Rosslyn

Pedestrian and Bicycle ModesPedestrian and bicycle demand was coded based on count data. Crosswalks were modeled at everyintersection, including midblock crossings on N. Lynn Street and N. Moore Street between WilsonBoulevard and 19th Street N. Crosswalks were also modeled at parking garage entrances and exits.Bicycle facilities were modeled along N. Lynn Street, Clarendon Boulevard, Wilson Boulevard, and KeyBoulevard (on-street bicycle lanes) as well as north of westbound Lee Highway (Custis Trail). Bicyclerouting decisions were used for bicycle facilities, and bicycles were assumed to use crosswalks at otherlocations, per the recorded count data. Seasonal factors developed from bicycle count station data wasused to normalize counts collected from different months of the year. Conflict areas and priority ruleswere coded for turning vehicles that conflict with non-motorized modes.

VISSIM Model Calibration MethodologyCalibration CriteriaThe VISSIM models were calibrated to existing traffic conditions generally using guidance provided inthe TOSAM Version 1. Volume, travel time and queue length calibration measures deviate slightly fromTOSAM per the project scope and agreed-upon Forecasting and Traffic Operations Analysis FrameworkDocument. Table 4 summarizes the measures and criteria used to evaluate the effectiveness of modelcalibration as well as the specific data sources used to calibrate the models.


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Table 4. Calibration Items and Targets

Simulated Measure Calibration Threshold Field Data Source

Simulated Traffic Volume for PeakHour· At intersections, difference

targets must be met for atleast 85% of approaches

· For freeways, differencetargets must be met for atleast 85% of freeway mainlinesegments and ramps

Within ± 20% for <100 vphWithin ± 15% for ≥100 vph to<300 vphWithin ± 10% for ≥300 vph to<1,000 vphWithin ± 5% for ≥1,000 vph

Balanced peak hour trafficcounts(June 2014 – November2017)

Simulated Travel Time for PeakPeriodDifference targets must be met fora minimum of 85% of travel timeroutes. Four arterial routes andthree freeway routes were usedfor calibration.

Within ± 1 minute for routeswith observed travel times thatare less than 7 minutesWithin ± 15% for routes withobserved travel times that aregreater than 7 minutes

Primary1: Google Maps API(November 28 – December14, 2017)

Secondary1: Travel TimeRuns(November 15 – 16, 2017)

Maximum Simulated QueueLength for Peak PeriodCalibration target must be met fora minimum of 85% of the criticallocations. Queue impact were usedto justify calibration in addition toquantitative comparison of queuelength.

Modeled queues qualitativelyreflect the impacts of observedqueues in the following area:· Spillback to adjacent

intersections· Spillback from ramp

intersection to freewaymainline and vice versa

· Spillback from turn lanes

Field observations –Wednesday November 29,2017

Visual Review of BottleneckLocations for Simulation PeriodSimulated average speed (milesper hour) were compared withprobe vehicle data for the freewaysegments (I-66, Route 110, andArlington Boulevard)

Speed heat map were plottedfor freeway segments toqualitatively review the patternsand duration of congestions

Field observations –Wednesday November 29,2017

INRIX – October 20171Google Maps API travel time was used for calibration of all routes that are detailed in the data collection summary of existingreport except for westbound Wilson Boulevard. Travel time run data is used for this route because the Google Maps routeextends beyond the extents of the VISSIM model. Travel time data were collected from Google API in 5-minute intervals overthe defined period and were aggregated to the peak periods.

Error CheckingPrior to calibration, error checking was completed through a visual review of the simulation andcomprehensive review of the error log to identify coding errors that could impact the model results. This


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included identifying missing conflict area and locations where signal timing were not be operatingcorrectly. Given the highly-saturated traffic conditions, numerous closely spaced intersections, andheavy pedestrian activity, the simulation and coding was reviewed in detail to prevent unrealisticnetwork gridlock.

Number of Runs RequirementMicrosimulation results inherently vary between runs due to random seed numbers, so results are anaverage of multiple microsimulation runs. The VDOT Sample Size Determination Tool was used todetermine the appropriate number of simulation runs at a 95th percentile confidence level. Initial modelruns with ten seeds were conducted, and the tool was used with the following measures ofeffectiveness to determine the required number of runs for the AM and PM models:

· Travel time on northbound N. Lynn Street, southbound Fort Myer Drive, eastbound ClarendonBoulevard, and westbound Wilson Boulevard

· Throughput on northbound N. Lynn Street and southbound Fort Myer Drive at 19th Street N.· Throughput on eastbound and westbound I-66 between Lee Highway and Route 110

The resulting required number of runs was ten for both AM and PM peak periods. As such, all resultsreported are an average of ten microsimulation runs.

Calibration Parameters and AdjustmentsCalibration of the VISSIM models to meet the calibration targets required adjusting specific parametersto achieve the desired throughput, travel time, queue lengths, and speeds.

Lane Change DistanceLane change distance is the distance in the VISSIM model where a vehicle will start attempting to makea lane change to a target lane prior to an off-ramp, a lane drop, or change in direction in travel. This lanechange distance is a parameter on every connector in the VISSIM network, and its default changedistance value is 656 feet. This parameter was adjusted on a case-by-case basis at different locationswith the goal of replicating observed field conditions. It was increased on freeway exits andoversaturated arterial movements to replicate the advanced lane changing that was observed in thefield. In some cases, lane change distance was reduced from the VISSIM default value to achieve betterlane utilization at locations with closely spaced intersections or on-ramp lane drops, such as on 19th

Street N., Wilson Boulevard, and the eastbound I-66 on-ramp from Lee Highway.

Driver BehaviorVISSIM incorporates two different car-following models – one for freeways and one for arterials. Asidefrom roadway geometrics, driver behavior has the greatest impact on roadway capacity by adjustingvehicle spacing, headways, and lane changing behavior. Car-following and lane-changing parameterswere modified for selected locations during the calibration process based on recommended values fromguidance documents, previous experience with similar types of networks and operations, engineeringjudgment, and field observations. The VISSIM models contain link display colors that correspond to thevarious link behaviors to assist with review and calibration.

Table 5 provides a list of driver behaviors used in the models, associated parameters some of which (inbold) were modified from the default values, and example application areas.


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Table 5. VISSIM Driver Behaviors

Parameters Freeway(Default)

FreewayMedium

Aggressive

Freeway HighAggressive

Freeway ReducedCapacity

Arterial(Default)

ArterialAggressive

ArterialAggressive –

High Capacity

ArterialAggressive –

Very HighCapacity

ArterialReducedCapacity

CarF

ollo

win

gPa

ram

eter

s

Look Ahead Distance: Num. ofObserved Vehicles 2 2 2 2 4 4 4 4 4

CC0 (Standstill Distance) (ft) 4.92 4.92 4.92 5.61 N/A N/A N/A N/A N/ACC1 (Headway Time) (s) 0.9 0.9 0.9 1.1-1.40 N/A N/A N/A N/A N/ACC2 (Following Variation) (ft) 13.12 13.12 13.12 25.00 N/A N/A N/A N/A N/AAverage Standstill Distance (ft) N/A N/A N/A N/A 6.56 6.56 5.00 5.00 6.56Additive Part of SafetyDistance N/A N/A N/A N/A 2.00 2.00 1.50 1.50 2.50

Multiplicative Part of SafetyDistance N/A N/A N/A N/A 3.00 3.00 2.50 2.50 3.50

Lane

-Cha

ngin

gPa

ram

eter

s

Maximum Deceleration(Own Vehicle) (ft/s2) -13.12 -16.50 -25.98 -13.12 -13.12 -15.00 -15.00 -15.00 -13.12

Maximum Deceleration(Trailing Vehicle) (ft/s2) -9.84 -14.99 -18.01 -9.84 -9.84 -12.00 -12.00 -12.00 -9.84

Accepted Deceleration(Own Vehicle) (ft/s2) -3.28 -7.02 -14.01 -3.28 -3.28 -3.28 -3.28 -3.28 -3.28

Accepted Deceleration(Trailing Vehicle) (ft/s2) -1.64 -4.00 -8.99 -1.64 -3.28 -3.28 -3.28 -3.28 -3.28

Minimum Headway 1.64 1.44 1.31 1.64 1.64 1.50 1.50 1.50 1.64Safety Dist. Reduction Factor 0.60 0.25 0.10 0.60 0.60 0.25 0.25 0.25 0.80Maximum Deceleration forCooperative Braking (ft/s2) -9.84 -16.90 -27.89 -9.84 -9.84 -15.00 -15.00 -15.00 -9.84

Advanced Merging Off On On Off Off On On On OffCooperative Lane Change Off On On On Off On On On Off

Use Cases Default for allfreeway links

Weave ormerge which

see highthroughputs

Short weave ormerge areas

Major bottlenecklocations

Default for allarterial links

Short arterialweaving or

merging areas

Segments withobserved closecar following

Oversaturatedsegments with

highthroughput

Segments withsignificantweaving

Example Locations Most basic freewaylinks

EB ArlingtonBlvd

approaching N.Meade St

WB I-66 weavefrom Route110; EB I-66

merge from SBGW Parkway

EB TheodoreRoosevelt Bridge Most arterial links

NB/SB KeyBridge, EB/WBWilson Blvd in

PM

NB Lynn St, EBWilson Blvd in

AM

EB Lee Hwy atN. Lynn St

SB Fort MyerDr at Fairfax Dr

in PM


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Conflict Areas and Priority RulesSome conflict areas parameters were modified at locations in which field observations suggested thatdrivers were willing to accept shorter gaps or were more inclined to block other movements. Thisinvolved reducing the front gap, rear gap, safety distance factor, and avoid blocking parameters.

Priority rules were used to help prevent complete intersection blocking. They were also used forpreventing turning vehicles from conflicting with heavy pedestrian movements when use of conflictareas would cause unrealistic network gridlock.

External CongestionSome locations in the study area operate under constrained conditions due to queue spillback fromoutside of the study area, namely northbound on Key Bridge and eastbound on Theodore RooseveltBridge. A traffic signal was added to the edge of the network on Key Bridge to replicate queue spillbackfrom the intersection with M Street NW. Signal phasing and timing was approximated based on fieldobservations of the signal operations. Congestion was replicated on the Theodore Roosevelt Bridgeleaving the network using time-dependent and lane-dependent reduced speed areas and by trafficrouting based on known weaving patterns at the edge of the network. Speeds were set based on probevehicle average speeds and local knowledge of traffic operations.

Signal AdherenceYellow change intervals of signal timings were changed slightly in some locations where vehicles,pedestrians, or cyclists were observed to use a greater amount of the yellow interval than what wassimulated in VISSIM. The yellow clearance interval of the congested vehicular movements (#1, #2, and#3 below) were shortened to provide more green time to achieve greater throughput. Crosswalk or trailcrossing pedestrian clearance intervals were reduced at one location (#4 below) to provide more WALKtime. The crossings were previously observed to take multiple cycles to clear the pedestrian demand inVISSIM whereas in the field pedestrians were observed to cross the intersection in each cycle. Bydefault, pedestrians and bicycles strictly adhere to flashing DON’T WALK signal indications in VISSIM.

1. Eastbound Lee Highway and N. Lynn Street2. Eastbound Lee Highway and Fort Myer Drive3. Westbound Fairfax Drive at N. Lynn Street4. Eastbound/westbound pedestrian and bicycle crossing of Fort Myer Drive along westbound Lee

Highway (Custis Trail)

Pick-Up and Drop-Off ActivityFrequent passenger pick-up and drop-off activity was observed in the rightmost lane of N. Lynn Streetbetween 19th St N. and eastbound Lee Highway in both AM and PM. This activity was replicated inVISSIM using parking lot vehicle routes and a parking area in this lane. Vehicles were coded to stop hereat a rate of approximately one vehicle per minute and park for an average duration of 20 seconds andup to two minutes.

Lane UtilizationIn the AM, buses from southbound N. Moore Street were observed using the eastbound through lane(rightmost lane) at the intersection of 19th Street N. and N. Lynn Street to turn left to head northboundtoward Lee Highway and I-66. To replicate this de facto turning movement, transit buses destined for


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eastbound I-66 were allowed to make this movement in the AM VISSIM model. Replication of thisbehavior was also required for volume and throughput calibration along these streets.

Calibration ResultsExisting AM ModelAn overall summary of the calibration results of the existing AM VISSIM model is included in Table 6.Overall, all calibration criteria were met. Detailed calibration results can be found in Attachment A.

Table 6. AM Calibration Summary

Calibration Item Basis Total Percent Target TargetMet

Simulated Traffic Volume(Intersections)

Approaches(n = 79) 74 94% 85% Yes

Simulated Traffic Volume(Freeways)

Segments(n = 35) 34 97% 85% Yes

Simulated Travel Time(Arterials and Freeways)

Routes(n = 10) 9 90% 85% Yes

Maximum Simulated Queue Length(Critical Locations)


Visual Review of Bottleneck LocationsFreeway

Segments - - - Yes

AM Volume CalibrationThroughput volumes produced from the VISSIM model for the AM peak hour were compared with trafficcounts for intersection approaches and freeway segments. Intersection volume calibration wasaccomplished for 94% of approaches. The approaches not meeting the calibration criteria are primarilylow volume approaches where a small difference is a large overall percentage of the target volume.Freeway volume calibration was accomplished for 97% of segments. The only segment not meeting thecalibration criteria is the eastbound Arlington Boulevard on-ramp from N. Meade St, which isconstrained by heavy congestion along Arlington Boulevard.

AM Travel Time CalibrationAverage travel times produced from the VISSIM model for the AM peak period were compared withfield measurements for four arterial routes and six freeway routes. Travel time calibration wasaccomplished for 90% of travel time routes. The only route not meeting the calibration criteria iseastbound Arlington Boulevard, which has a slightly longer model travel time than the average peakperiod field travel time. The model travel time is within the magnitude of travels times observed forshorter durations within the peak period, and the visual review of the eastbound Arlington Boulevardbottleneck calibration is comparable to INRIX speed data.

AM Queue Length CalibrationAverage and maximum queue lengths produced from the VISSIM model for the AM peak period werecompared against observed field measurements at 18 critical intersection or ramp approaches, asagreed upon by Arlington County. Both measures were observed to qualitatively assess whethermodeled queues reflect the impacts of observed queues (e.g., spillback from a ramp intersection, turn


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bay, or downstream intersection). It was determined, based on engineering judgement and knowledgeof area travel patterns, that all critical locations adequately represent field conditions. In severallocations, field measurements were constrained by sight distance or an upstream intersection, while theVISSIM queue length (as measured using queue counters in the model) will account for queues spillingback through upstream intersections. For example, VISSIM queues along eastbound 19th St N. at N. LynnStreet spill back to the intersection with Key Boulevard, at which point queues extend back along KeyBoulevard to the network extents. This was observed in the field and is known to occur from localknowledge of the study area.

AM Bottleneck CalibrationSpeed heat maps for freeways (I-66, Arlington Boulevard, Route 110) qualitatively reflect the patternsand duration of congestion. Model speeds in 15-minute interval by freeway segments are comparable toINRIX speed data for the magnitude and duration of the slow-downs. The VISSIM model speeds foreastbound I-66 are slightly faster than the INRIX speeds approaching the Arlington Boulevard rampslater in the simulation period (30 mph compared to 15-20 mph).

Existing PM ModelAn overall summary of the calibration of the existing PM VISSIM model is included in Table 7. Overall, allcalibration criteria were met. Detailed calibration results can be found in Attachment A.

Table 7. PM Calibration Summary

Calibration Item Basis Total Percent Target TargetMet

Simulated Traffic Volume(Intersections)


Simulated Traffic Volume(Freeways)

Segments(n = 35) 30 86% 85% Yes

Simulated Travel Time(Arterials and Freeways)

Routes(n = 10) 10 100% 85% Yes

Maximum Simulated Queue Length(Critical Locations)


Visual Review of Bottleneck Locations FreewaySegments - - - Yes

PM Volume CalibrationThroughput volumes produced from the VISSIM model for the PM peak hour were compared with trafficcounts for intersection approaches and freeway segments. Intersection volume calibration wasaccomplished with 86% of approaches. The approaches not meeting the calibration criteria are primarilydue to congestion entering the network onto southbound Fort Myer Drive from Key Bridge, whichconstrains southbound demand. Freeway volume calibration was accomplished with 86% of segments.The segments not meeting the calibration criteria are segments along eastbound I-66 impacted bycongestions on Theodore Roosevelt Bridge and are all less than 10 percent different from targetvolumes.


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PM Travel Time CalibrationAverage travel times produced from the VISSIM model for the PM peak period were compared with fieldmeasurements for four arterial routes and six freeway routes. Travel time calibration was accomplishedall travel time routes.

PM Queue Length CalibrationAverage and maximum queue lengths produced from the VISSIM model for the PM peak period werecompared against observed field measurements at 18 critical intersection approaches. Both measureswere observed to qualitatively assess whether modeled queues reflect the impacts of observed queues.It was determined that 17 of the 18 critical locations (94%) adequately represented field conditions.Eastbound Key Boulevard at N. Nash Street has slightly longer model queues than observed, andcalibration of this queue length is more critical for AM and not PM.

PM Bottleneck CalibrationThe speed heat maps for freeways (I-66, Arlington Boulevard, Route 110) qualitatively reflect thepatterns and duration of congestion. Model speeds in 15-minute interval by freeway segments arecomparable to INRIX speed data for the magnitude and duration of the slow-downs. The VISSIM modelspeeds for eastbound Arlington Boulevard are slightly faster than field observed speeds approachingTheodore Roosevelt Bridge (30 mph compared to 15-20 mph).

ConclusionsBased on the results obtained from the AM and PM VISSIM models and comparison to field data forvolume, travel time, queue length, and bottlenecks/speeds, it is concluded that the models arereasonably calibrated to replicate existing multimodal traffic operations as well as to meet the requiredstandards established for the project. These models will be used for future scenario assessment uponthe development of future volumes and concepts.

AM Calibration Summary

AM Peak Period Calibration Summary

Calibration Item Basis Criteria Total Percent TargetTarget

Met

Within ± 20% for <100 vph

Within ± 15% for ≥ 100 vph to < 300 vph

Within ± 10% for ≥ 300 vph to < 1,000 vph

Within ± 5% for ≥ 1,000 vph

Within ± 20% for <100 vph




Within ± 1 minute for routes with observed travel times that are less than 7

minutes

Within ± 15% for average observed travel time that

are greater than 7 minutes

Maximum Simulated

Queue Length

Approaches(n = 18)

Modeled queues qualitatively reflect the impacts of observed

queues

18 100% 85% Yes

Visual Review of Bottleneck Locations

Freeway Segments

Speed heat maps qualitatively reflect

patterns and duration of congestions

Yes

9 90% 85% Yes

Simulated Traffic Volume

(Intersections)

Routes(n = 10)


(Freeways)

Segments(n = 35)

YesApproaches

(n = 79)74 94% 85%

34 97% 85% Yes

Simulated Travel Time

AM Volume Calibration (Intersections)

Volume Calibration (Intersections)

AM Peak Hour (8:00-9:00 AM)

Subtotal Total Percent Target15

15

30

14

# Intersection Approach Movement

TH 1,370 1,386 16 1%RT 577 563 -14 -2%LT 34 33 -1 -3%TH 716 659 -57 -8%

TH 1,098 1,108 10 1%RT 305 294 -11 -4%LT 119 141 22 18%TH 194 186 -8 -4%

LT 400 409 9 2%TH 817 836 19 2%TH 1,621 1,623 2 0%RT 293 308 15 5%

LT 260 261 1 0%TH 689 742 53 8%RT 242 218 -24 -10%TH 235 262 27 11%RT 154 111 -43 -28%LT 102 96 -6 -6%TH 150 157 7 5%

LT 198 200 2 1%TH 131 122 -9 -7%

Tunnel 452 442 -10 -2%RT 57 42 -15 -26%TH 825 751 -74 -9%RT 107 91 -16 -15%

U-Turn 28 31 3 11%LT 141 123 -18 -13%TH 605 608 3 0%

LT 75 80 5 7%RT 24 21 -3 -13%LT 79 66 -13 -16%TH 128 139 11 9%TH 4 2 -2 -50%RT 15 17 2 13%

1

2

3

4

5

6

2,410

101

205

19

325

15

-32

-90

-134

207

Fort Myer Drive and

Wilson Blvd

SB 838 -4%

EB 932 -10%842

WB 19 0%

-1%

2

-2N. Nash

Street and 17th Street

N.

SB

Intersection 325 0%

0

0

99 2%

EB

Intersection 2,544 -5%

WB 774 762 -12 -2%

Fort Myer Drive and

19th Street N../N. Nash

Street

SB 1,191 3%

EB

1,221

373

253

1,847

806

Intersection 1,832 1%

1,931 17

45

30

Fort Myer Drive and EB

Lee Hwy

SB 1,217 2%

EB

389 -4%

WB 252 0%


-16

1

1,914

327

1,729

1,245

13

28

3,176

Fort Myer Drive and

WB Lee Hwy

SB

1,947 0%

WB 750 -8%


1,949

692

2,641

2

-58

-56

1,403 0%

WB 313 4%

-1

14

1%

Target Met

Yes

Volume CriteriaWithin ± 20% for < 100 vph




Balanced Count (vph)

Difference (%)

Southbound Key Bridge and George Washington

Parkway

SB


VISSIM Throughput (vph)

Difference (vph)

1,402

Approaches(n = 79)

74 94% 85%


# Intersection Approach MovementBalanced Count

(vph)Difference (%)

Southbound


Difference (vph)

LT 44 72 28 64%

TH 530 471 -59 -11%

RT 65 42 -23 -35%

TH 141 128 -13 -9%

RT 183 181 -2 -1%

LT 51 50 -1 -2%

TH 48 43 -5 -10%

LT 98 93 -5 -5%TH 1,235 1,253 18 1%TH 475 425 -50 -11%RT 289 276 -13 -4%

LT 52 58 6 12%

TH 1 0 -1 -100%

RT 454 447 -7 -2%

NB RT 31 31 27 27 -4 -4 -13% -13%EB TH 1,854 1,854 1,847 1,847 -7 -7 0% 0%

LT 14 25 11 79%TH 9 18 9 100%RT 11 5 -6 -55%LT 60 74 14 23%TH 416 431 15 4%RT 19 20 1 5%LT 27 28 1 4%TH 241 250 9 4%RT 86 84 -2 -2%

SB RT 87 87 89 89 2 2 2% 2%EB TH 1,051 1,051 975 975 -76 -76 -7% -7%WB TH 687 687 669 669 -18 -18 -3% -3%

LT 115 130 15 13%TH 2,626 2,529 -97 -4%TH 198 197 -1 -1%RT 524 534 10 2%

TH 1,759 1,658 -101 -6%RT 182 211 29 16%LT 982 1,004 22 2%TH 903 869 -34 -4%

7

8

9

10

11

12

13

NB 1,941 1,869 -72 -4%

1,873

3,742 -84

SB

EB

639

324

NB

3,463

6%

2%

NB 2,741 2,659 -82 -3%

1,825 -5%

Intersection 883 6%

-92

Intersection 2,604

9

-73

1%

Intersection

-2%

WB -6%

Intersection -7%

-12

495

354

525

362

30

8

52

-6

-75

-2

-52

935

1,874

48

585

309

701

1,346

987

505

2,552

99

1,062

93

-11

14

-2%

N. Lynn Street and

EB Lee HwyEB 1,885 -1%


N. Lynn Street and

WB Lee HwyWB 722

N. Moore Street and

Wilson BlvdIntersection 1,733

731

3,390

1,885 -1%

N. Moore Street and 19th St N.

SB 34 41%

Intersection

EB

WB

N. Moore Street and

EB Lee Hwy

Fort Myer Drive and

Fairfax Drive

Fort Myer Drive/N.

Meade Street and WB

Arlington Blvd Ramp

SB

1,333

764

-54

-15

13

-63

-8%

-5%

-8%

1%

WB 507 0%



(vph)Difference (%)

Southbound


Difference (vph)

LT 122 131 9 7%TH 1,435 1,347 -88 -6%RT 82 72 -10 -12%LT 183 208 25 14%TH 247 247 0 0%TH 232 229 -3 -1%RT 323 316 -7 -2%

LT 202 178 -24 -12%TH 1,288 1,307 19 1%RT 252 238 -14 -6%LT 610 574 -36 -6%TH 441 398 -43 -10%TH 485 491 6 1%RT 3 11 8 267%

NB TH 264 264 279 279 15 15 6% 6%EB LT 22 22 24 24 2 2 9% 9%

LT 27 26 -1 -4%TH 1,600 1,605 5 0%RT 62 57 -5 -8%LT 124 127 3 2%TH 61 43 -18 -30%TH 72 67 -5 -7%RT 51 52 1 2%

LT 66 68 2 3%TH 18 20 2 11%TH 10 11 1 10%RT 2 2 0 0%LT 35 18 -17 -49%TH 454 453 -1 0%RT 10 8 -2 -20%

TH 45 54 9 20%RT 173 148 -25 -14%LT 62 39 -23 -37%TH 31 37 6 19%LT 39 35 -4 -10%TH 1,679 1,742 63 4%RT 54 31 -23 -43%

LT 54 50 -4 -7%TH 169 149 -20 -12%TH 276 263 -13 -5%RT 116 112 -4 -3%LT 220 224 4 2%RT 162 154 -8 -5%

18

19

20

14

15

16

17

N. Nash Street and Key Blvd

NB 223 199 -24 -11%

SB 392 375 -17 -4%

EB 382 378 -4 -1%

Intersection 997 952 -45 -5%

EB 430 455 25 6%

1,550

Intersection 2,083

123

Intersection 286

-18%

EB 1,772 2%

595 580

202

76

1,723

-3%

N. Nash Street and

EB Lee Hwy

NB 218 -7%

SB

WB 499 -4%479

N. Nash Street and

WB Lee Hwy

NB 84 5%

SB 12 8%

88

13

0%

Intersection

1,808

2,086

93

3

-20

-15

-16

-17

36

4

1

-3%


N. Lynn Street and

Fairfax Drive

NB 1,689 0%

EB 185 -8%

WB

170

119

1,977

1,688

6%303 17

-1

-15

-4

-20

Intersection 3,281 -3%N. Lynn St and 17th St

N.

1,051 -8%

WB 488 3%14

N. Lynn Street and

Wilson Blvd

NB 1,742 -1%

EB

N. Lynn St and 19th St

N.

NB 1,639 -5%

972

502

3,197 -84

-89

-10

-74

-19

-79

WB 555 -2%


545

2,550



(vph)Difference (%)

Southbound


Difference (vph)

LT 13 6 -7 -54%TH 45 43 -2 -4%RT 36 34 -2 -6%LT 60 63 3 5%TH 44 63 19 43%RT 139 95 -44 -32%LT 96 92 -4 -4%TH 822 756 -66 -8%RT 6 4 -2 -33%

U-Turn 14 33 19 136%LT 49 33 -16 -33%TH 352 401 49 14%RT 247 214 -33 -13%

LT 31 28 -3 -10%RT 67 64 -3 -4%TH 177 152 -25 -14%RT 19 17 -2 -11%LT 16 12 -4 -25%TH 21 24 3 14%

LT 27 25 -2 -7%TH 321 324 3 1%RT 94 90 -4 -4%LT 362 311 -51 -14%TH 155 150 -5 -3%RT 10 12 2 20%LT 75 67 -8 -11%TH 114 96 -18 -16%RT 55 47 -8 -15%

LT 103 106 3 3%TH 27 28 1 4%RT 41 38 -3 -7%LT 3 3 0 0%TH 0 0 0 0%RT 60 59 -1 -2%LT 153 150 -3 -2%TH 137 129 -8 -6%RT 39 41 2 5%LT 8 8 0 0%TH 392 388 -4 -1%RT 36 34 -2 -6%

LT 187 169 -18 -10%TH 407 381 -26 -6%TH 666 665 -1 0%RT 153 151 -2 -1%

21

22

23

24

25

-15 -2%

N. Kent Street and

Wilson Blvd

EB 594 550 -44 -7%

WB 819 816 -3 0%

Intersection 1,413 1,366 -47 -3%

N. Kent Street and 19th St N.

NB 171 172 1 1%

SB 63 62 -1 -2%

EB 329 320 -9 -3%

WB 436 430 -6 -1%

Intersection 999 984

N. Meade St and EB

Arlington Blvd

NB 442 439 -3 -1%

SB 527 473 -54 -10%

EB 244 210 -34 -14%

Intersection 1,213 1,122 -91 -8%

-86 -4%

N. Nash Street and Arlington

Blvd

NB 98 92 -6 -6%

EB 196 169 -27 -14%

WB 37 36 -1 -3%


N. Nash St and Wilson

Blvd

NB 94 83 -11 -12%

SB 243 221 -22 -9%

EB 924 852 -72 -8%

WB 662 681 19 3%

Intersection 1,923 1,837



(vph)Difference (%)

Southbound


Difference (vph)

LT 8 7 -1 -13%TH 5 5 0 0%RT 31 30 -1 -3%LT 28 28 0 0%TH 5 6 1 20%RT 30 29 -1 -3%LT 69 61 -8 -12%TH 321 301 -20 -6%RT 17 17 0 0%LT 6 5 -1 -17%TH 781 780 -1 0%RT 555 565 10 2%

LT 133 126 -7 -5%TH 78 74 -4 -5%TH 117 109 -8 -7%RT 71 74 3 4%TH 431 444 13 3%RT 73 58 -15 -21%

TH 75 73 -2 -3%RT 36 35 -1 -3%LT 70 66 -4 -6%TH 47 44 -3 -6%LT 136 127 -9 -7%TH 818 752 -66 -8%

26

27

36

N. Oak Street and

Clarendon Blvd

NB 111 108 -3 -3%

SB 117 110 -7 -6%

EB 954 879 -75 -8%

Intersection 1,182 1,097 -85 -7%

N. Arlington Ridge Road and Wilson

Blvd

NB 44 42 -2

903 885 -18 -2%

N. Oak Street and Wilson

Blvd

NB 211 200 -11 -5%

SB 188 183 -5 -3%

WB 504 502 -2 0%

Intersection

WB 1,342 1,350 8 1%


-5%

SB 63 63 0 0%

EB 407 379 -28 -7%

-22 -1%

AM Volume Calibration (Freeways)

Volume Calibration (Freeways)

AM Peak Hour (8:00-9:00 AM)

Subtotal Total Percent Target Target Met0

0

11

23

Interchange TypeBalanced

Count(vph)

VISSIM Through-put (vph)

Difference(vph)

Difference(%)

Basic 2,576 2,557 -19 -1%Ramp 1,085 1,078 -7 -1%Weave 3,661 3,557 -104 -3%Ramp 941 910 -31 -3%Basic 2,720 2,631 -89 -3%Ramp 859 820 -39 -5%Merge 3,579 3,473 -106 -3%Ramp 1,074 1,038 -36 -3%Basic 4,653 4,511 -142 -3%

Diverge 2,855 2,853 -2 0%Ramp 1,177 1,168 -9 -1%Ramp 367 363 -4 -1%Ramp 810 803 -7 -1%Basic 1,678 1,678 0 0%Ramp 1,023 1,022 -1 0%Weave 2,701 2,712 11 0%Ramp 722 733 11 2%Basic 1,979 1,978 -1 0%

Diverge 2,922 2,920 -2 0%Ramp 937 965 28 3%Basic 1,985 1,969 -16 -1%Ramp 570 480 -90 -16%Weave 2,555 2,476 -79 -3%RampRamp 1,481 1,441 -40 -3%RampRamp 390 396 6 2%Ramp 1,200 1,195 -5 0%Ramp 766 761 -5 -1%Weave 1,966 1,951 -15 -1%Ramp 507 509 2 0%Basic 1,459 1,439 -20 -1%Ramp 388 364 -24 -6%Merge 1,847 1,794 -53 -3%Basic 2,365 2,373 8 0%RampBasicBasic 380 358 -22 -6%RampBasic 1,321 1,270 -51 -4%

See Wilson Blvd/Arlington Ridge Rd intersection

See Eastbound I-66 above

See I-66 Eastbound above

Off-ramp to GW PkwyOff-ramp to WB US 50

See I-66 Westbound above

On-ramp from NB GW Pkwy

See Westbound I-66 above

Off-ramp to EB I-66Off-ramp to SB GW Pkwy

On-ramp from WB I-66On-ramp from SB GW Pkwy

On-ramp from WB I-66 and SB GW Pkwy

Between Ramps

Route 110 Southbound

Route 110 Northbound

UpstreamOff-ramp to WB I-66

US 50 Westbound

Off-ramp to NB N Lynn St

Downstream (Wilson Blvd)Upstream (Wilson Blvd)On-ramp from I-66 EB

Downstream

Between RampsOn-ramp from SB Ft Myer Dr

Downstream

US 50 Eastbound

UpstreamOff-ramp to NB N Meade St

I-66 Westbound

I-66 Eastbound

Downstream

Between RampsOn-ramp from N Meade St

Between Ramps

On-ramp from NB Route 110Between Ramps

Off-ramp to WB Lee Hwy/Key Bridge

Off-ramp to WB US 50 and GW Pkwy

Between Ramps

On-ramp from EB US 50Downstream

Upstream

On-ramp from SB GW PkwyBetween Ramps

Between RampsOff-ramp to SB Route 110

Between Ramps

Segment

UpstreamOn-ramp from EB Lee Hwy

YesWithin ± 15% for ≥ 100 vph to < 300 vph



85%

Volume Criteria

Segments(n = 35)

Within ± 20% for < 100 vph

34 97%

AM Travel Time Calibration

Travel Time CalibrationTravel Time - AM Peak Period (7:30-9:30 AM)

Travel Time Criteria Subtotal Total Percent Target Target MetWithin ± 1 minute for routes with observed travel times that are less than 7 minutes

9

Within ± 15% for average observed travel time that are greater than 7 minutes

0

Field(MM:SS)

VISSIM(MM:SS)

Difference(MM:SS)

Difference(%)

100 05:47 05:27 -00:20 -6%

200 02:25 03:01 00:36 25%

300 04:27 05:17 00:50 19%

400 02:58 02:23 -00:35 -20%

500 03:24 04:17 00:54 26%

600 01:41 01:44 00:03 3%

700 08:13 09:38 01:26 17%

800 01:21 01:28 00:07 9%

900 00:50 00:56 00:06 11%

1000 00:32 00:32 -00:01 -3%Southbound Route 100(N. Arlington Ridge Rd to Memorial Ave)

Routes(n = 10)

Northbound Route 110(Memorial Ave to WB I-66)

Route

Arterial Routes

Freeway Routes

Northbound Lynn St(Arlington Blvd to George Washington Memorial Pkwy)Southbound Fort Myer Dr(George Washington Memorial Pkwy to Arlington Blvd)

9 90% 85% Yes

Peak Period Travel Time

Westbound Arlington Boulevard(Roosevelt Bridge to N. Rolfe St)

Eastbound Clarendon Blvd(N. Rhodes St to N. Arlington Ridge Rd)Westbound Wilson Blvd(N. Arlington Ridge Rd to N. Oak St)

Segment ID

Eastbound I-66(EB Lee Hwy off-ramp to Roosevelt Bridge)

Eastbound Arlington Boulevard(N. Rolfe St to Roosevelt Bridge)

Westbound I-66(Roosevelt Bridge to 21st St N. overpass)

AM Queue Length Calibration

Queue Length Calibration

AM Peak Period (7:30-9:30 AM)

Total Percent Target Target Met

Approaches(n = 18)

18 100% 85% Yes

Observed Max

Queue (feet)

VISSIM Max

Queue (feet)

VISSIM Average Queue (feet)

Max Queue

Difference (feet)

Max Queue

Difference (%)

Field Conditions

Represented (Yes/No)

Notes

360 1,593 408 1,233 343% YQueue spills back upstream into

Rosslyn core

2,640 1,763 834 -877 -33% YQueue spills back upstream into

Rosslyn core920 1,100 1,032 180 20% Y Queue spills back to GWP

1,380 2,024 657 644 47% YQueue spills back into mainline

weave area3,200 2,702 886 -498 -16% Y Queue reaches N. Scott St Bridge

130 740 118 610 469% Y

Average queue represents observed typical condition within the block of

19th St N. and EB Lee Hwy; maximum queue length reflects

occasional rolling queue spillback back to Lee Hwy

1,520 1,086 154 -434 -29% YQueue spills back along EB Key Blvd

to edge of network (N. Quinn St)

2,200 2,346 442 146 7% Y Queue spills back past Fort Myer Dr

1,275 1,136 404 -139 -11% Y

Queue representative of occasional spill back onto EB Arlington Blvd on-

ramp, consistent with field observations.

Queue CriteriaModeled queues qualitatively reflect the

impacts of observed queues (e.g., spillback from ramp intersections, turn bay, or

downstream intersection)

EB Key Blvd at N. Nash St

EB 19th St N. at N. Lynn St

NB N. Lynn St at Wilson Blvd

NB N. Lynn St at Key Bridge

SB GW Parkway off-ramp to Key

WB I-66 off-ramp at N. Lynn St

EB Lee Hwy N. Lynn St

SB Fort Myer Dr at 19th St N.

Location

NB N. Lynn St at Fort Myer Dr/GW Parkway on-ramp


Observed Max

Queue (feet)

VISSIM Max

Queue (feet)


Max Queue

Difference (feet)

Max Queue

Difference (%)

Field Conditions


NotesLocation

900 1,012 290 112 12% Y

Queue is metered by signal at Fort Myer Dr; max queue can spill back upstream through several closely-

spaced intersections to N. Oak St as can be observed within sight distance

in the field

1,330 1,278 208 -52 -4% Y

Queue is metered by upstream intersections; max queue can spill back along Wilson Blvd/Clarendon Blvd out of Rosslyn core (west of N.

Oak St) as observed in the field

300 351 45 51 17% Y Queue fills block back to N. Lynn St

900 2,083 575 1,183 131% Y

Maximum queue extends to N. Pierce St per observation; slow-moving

platoon (maximum rolling queue) is observed to extend to N. Rhodes St

(1,800 feet)

390 394 69 4 1% YQueue fills block back to Fort Myer

Dr

100 280 41 180 180% YAverage queue represents observed typical condition with minimal queuing

impacts on N. Moore St

680 1,597 449 917 135% YQueueing back to EB Arlington

Boulevard off-ramp to N. Meade St

WB Wilson Blvd at Fort Myer Dr

EB Clarendon Blvd at N. Oak St

WB Wilson Blvd at N. Oak St

SB N. Moore St at Wilson Blvd

NB N. Lynn St at Fairfax Dr

EB Wilson Blvd at N. Lynn St

EB Wilson Blvd at Fort Myer Dr


Observed Max

Queue (feet)

VISSIM Max

Queue (feet)


Max Queue

Difference (feet)

Max Queue

Difference (%)

Field Conditions


NotesLocation

1,930 2,651 1,078 721 37% Y

Queue measurement in VISSIM includes Arlington Blvd EB frontage road; queues along on-ramp spill

back from Arlington Blvd back to N. Meade St as observed in the field; the maximum queue on Arlington Blvd frontage road is 1,200 feet

1,600 2,172 466 572 36% Y

Queue spills back onto Arlington Blvd EB mainline as observed in the field. Observed queue length is limited to

sight distance.

EB Arlington Blvd on-ramp from N. Meade St

EB Arlington Blvd off-ramp to N. Meade St

AM Bottleneck Calibration

7:30 AM 7:30 AM

8:00 AM 8:00 AM

8:30 AM 8:30 AM

9:00 AM 9:00 AM

9:30 AM 9:30 AM

10:00 AM 10:00 AM

10:30 AM 10:30 AM

7:30 AM 7:30 AM

8:00 AM 8:00 AM

8:30 AM 8:30 AM

9:00 AM 9:00 AM

9:30 AM 9:30 AM

10:00 AM 10:00 AM

10:30 AM 10:30 AM

Freeway Average Speed ComparisonEastbound I-66

VIS

SIM

SP

EE

D

VIS

SIM

SP

EE

D

OB

SE

RV

ED

SP

EE

D

OB

SE

RV

ED

SP

EE

D

Westbound I-66

D.C

.

Rou

te 1

10

US

50 R

amp

N S

cott

Stre

et

N L

ynn

Stre

et

D.C

.

Rou

te 1

10

US

50 R

amp

N S

cott

Stre

et

N L

ynn

Stre

et

0Average Speed (mph)

7050 6040302010 0Average Speed (mph)

7050 6040302010


7:30 AM 7:30 AM

8:00 AM 8:00 AM

8:30 AM 8:30 AM

9:00 AM 9:00 AM

9:30 AM 9:30 AM

10:00 AM 10:00 AM

10:30 AM 10:30 AM

7:30 AM 7:30 AM

8:00 AM 8:00 AM

8:30 AM 8:30 AM

9:00 AM 9:00 AM

9:30 AM 9:30 AM

10:00 AM 10:00 AM

10:30 AM 10:30 AM

Freeway Average Speed Comparison

VIS

SIM

SP

EE

D

VIS

SIM

SP

EE

DO

BS

ER

VE

D S

PE

ED

OB

SE

RV

ED

SP

EE

D

Eastbound Arlington Blvd Westbound Arlington Blvd

Roo

seve

ltB

ridge

N M

eade

Stre

et

N R

hode

sSt

reet

Roo

seve

ltB

ridge

N M

eade

Stre

et

N R

hode

sSt

reet


7050 6040302010


7:30 AM 7:30 AM

8:00 AM 8:00 AM

8:30 AM 8:30 AM

9:00 AM 9:00 AM

9:30 AM 9:30 AM

10:00 AM 10:00 AM

10:30 AM 10:30 AM

7:30 AM 7:30 AM

8:00 AM 8:00 AM

8:30 AM 8:30 AM

9:00 AM 9:00 AM

9:30 AM 9:30 AM

10:00 AM 10:00 AM

10:30 AM 10:30 AM

VIS

SIM

SP

EE

DO

BS

ER

VE

D S

PE

ED

Freeway Average Speed ComparisonNorthbound Route 110 Southbound Route 110

VIS

SIM

SP

EE

DO

BS

ER

VE

D S

PE

ED

Mem

oria

l Driv

e

I-66

I-66

Mem

oria

l Driv

e


7050 6040302010

PM Calibration Summary

PM Peak Period Calibration Summary

Calibration Item Basis Criteria Subtotal Total Percent TargetTarget

Met

Within ± 20% for <100 vph 11


21


21


15

Within ± 20% for <100 vph 0


0


9


21

Within ± 1 minute for routes with observed travel times that are less than 7

minutes

Within ± 15% for average observed travel time that

are greater than 7 minutes

Maximum Simulated

Queue Length

Approaches(n = 18)

Modeled queues qualitatively reflect the impacts of observed

queues

17 94% 85% Yes

Visual Review of Bottleneck Locations

Freeway Segments

Speed heat maps qualitatively reflect

patterns and duration of congestions

Yes

85% Yes


(Intersections)

Routes(n = 10)


(Freeways)

Segments(n = 35)

YesApproaches

(n = 79)68 86% 85%

30 86% 85% Yes

Simulated Travel Time

10 100%

PM Volume Calibration (Intersections)

Volume Calibration (Intersections)

PM Peak Hour (5:00-6:00 PM)

Subtotal Total Percent Target11

21

21

15

# Intersection Approach Movement

TH 2,021 1,910 -111 -5%RT 434 406 -28 -6%LT 25 7 -18 -72%TH 709 676 -33 -5%

TH 1,663 1,546 -117 -7%RT 398 370 -28 -7%LT 122 125 3 2%TH 605 614 9 1%

LT 710 671 -39 -5%TH 1,075 991 -84 -8%TH 906 958 52 6%RT 304 276 -28 -9%

LT 90 80 -10 -11%TH 1,110 1,025 -85 -8%RT 191 177 -14 -7%TH 180 216 36 20%RT 136 147 11 8%LT 145 137 -8 -6%TH 170 162 -8 -5%

LT 253 247 -6 -2%TH 192 170 -22 -11%

Tunnel 919 865 -54 -6%RT 63 56 -7 -11%TH 787 800 13 2%RT 132 125 -7 -5%

U-Turn 40 41 1 3%LT 171 193 22 13%TH 514 524 10 2%

LT 33 34 1 3%RT 28 25 -3 -11%LT 30 42 12 40%TH 30 18 -12 -40%TH 16 14 -2 -13%RT 98 93 -5 -5%

1

2

3

4

5

6

3,021

59

60

107

226

-78

-89

6

-50

60

Fort Myer Drive and

Wilson Blvd

SB 1,427 -6%

EB 919 1%925

WB 114 -6%

0%

-2

0N. Nash

Street and 17th Street

N.

SB

Intersection 235 -4%

-7

-9

61 -3%

EB


WB 725 758 33 5%

Fort Myer Drive and

19th Street N../N. Nash

Street

SB 1,391 -8%

EB

1,282

363

299

1,944

1,338


1,234 24

-99

-109

Fort Myer Drive and EB

Lee Hwy

SB 1,785 -7%

EB

316 15%

WB 315 -5%


47

-16

1,210

739

2,655

1,662

-133

-123

2,896

Fort Myer Drive and

WB Lee Hwy

SB

2,455 -6%

WB 734 -7%


2,316

683

2,999

-139

-51

-190

2,061 -7%

WB 727 2%

-145

12

2%

Target Met

Yes

Volume CriteriaWithin ± 20% for < 100 vph




Balanced Count (vph)

Difference (%)

Southbound Key Bridge and George Washington

Parkway

SB



Difference (vph)

1,916

Approaches(n = 79)

68 86% 85%



(vph)Difference (%)

Southbound


Difference (vph)

LT 50 151 101 202%

TH 1,220 1,159 -61 -5%

RT 155 52 -103 -66%

TH 87 86 -1 -1%

RT 132 133 1 1%

LT 59 56 -3 -5%

TH 27 25 -2 -7%

LT 95 94 -1 -1%TH 745 747 2 0%TH 680 667 -13 -2%RT 731 682 -49 -7%

LT 97 101 4 4%

TH 1 0 -1 -100%

RT 479 497 18 4%

NB RT 182 182 134 134 -48 -48 -26% -26%EB TH 1,580 1,580 1,581 1,581 1 1 0% 0%

LT 23 17 -6 -26%TH 11 15 4 36%RT 67 83 16 24%LT 25 10 -15 -60%TH 229 266 37 16%RT 16 18 2 13%LT 19 14 -5 -26%TH 254 216 -38 -15%RT 20 6 -14 -70%

SB RT 159 159 143 143 -16 -16 -10% -10%EB TH 1,080 1,080 1,086 1,086 6 6 1% 1%WB TH 566 566 582 582 16 16 3% 3%

LT 292 316 24 8%TH 1,892 1,895 3 0%TH 435 428 -7 -2%RT 499 484 -15 -3%

TH 1,480 1,485 5 0%RT 321 274 -47 -15%LT 704 732 28 4%TH 1,058 979 -79 -7%

7

8

9

10

11

12

13

NB 1,801 1,759 -42 -2%

1,711

3,470 -93

SB

EB

1,425

219

NB

3,118

9%

-19%

NB 2,184 2,211 27 1%

1,805 0%

Intersection 664 -3%

6

Intersection 2,828

-22

5

-2%

Intersection

-1%

WB -6%

Intersection -4%

-51

270

293

294

236

24

-57

-19

-5

-68

21

-40

645

1,715

115

1,362

219

1,349

841

1,662

598

2,788

86

1,730

81

-47

14

0%

N. Lynn Street and

EB Lee HwyEB 1,762 -3%


N. Lynn Street and

WB Lee HwyWB 934

N. Moore Street and

Wilson BlvdIntersection 1,811

912

3,123

1,762 -3%

N. Moore Street and 19th St N.

SB 101 14%

Intersection

EB

WB

N. Moore Street and

EB Lee Hwy

Fort Myer Drive and

Fairfax Drive

Fort Myer Drive/N.

Meade Street and WB

Arlington Blvd Ramp

SB

840

1,411

-63

0

1

-62

-4%

0%

-4%

0%

WB 577 4%



(vph)Difference (%)

Southbound


Difference (vph)

LT 120 103 -17 -14%TH 1,323 1,296 -27 -2%RT 44 38 -6 -14%LT 160 188 28 18%TH 92 93 1 1%TH 173 132 -41 -24%RT 318 287 -31 -10%

LT 241 237 -4 -2%TH 902 934 32 4%RT 293 289 -4 -1%LT 375 374 -1 0%TH 705 712 7 1%TH 325 344 19 6%RT 245 221 -24 -10%

NB TH 251 251 230 230 -21 -21 -8% -8%EB LT 43 43 51 51 8 8 19% 19%

LT 19 15 -4 -21%TH 1,150 1,175 25 2%RT 55 55 0 0%LT 88 86 -2 -2%TH 49 52 3 6%TH 67 65 -2 -3%RT 55 56 1 2%

LT 66 44 -22 -33%TH 15 15 0 0%TH 10 10 0 0%RT 18 16 -2 -11%LT 37 42 5 14%TH 962 939 -23 -2%RT 4 3 -1 -25%

TH 58 52 -6 -10%RT 89 95 6 7%LT 32 30 -2 -6%TH 58 64 6 10%LT 23 7 -16 -70%TH 1,089 1,110 21 2%RT 89 88 -1 -1%

LT 96 62 -34 -35%TH 216 210 -6 -3%TH 174 167 -7 -4%RT 187 171 -16 -9%LT 100 150 50 50%RT 105 76 -29 -28%

18

19

20

14

15

16

17

N. Nash Street and Key Blvd

NB 312 272 -40 -13%

SB 361 338 -23 -6%

EB 205 226 21 10%


EB 252 281 29 12%

1,437

Intersection 1,438

122

Intersection 294

4%

EB 1,201 0%

1,112 1,069

147

94

1,460

-4%

N. Nash Street and

EB Lee Hwy

NB 147 0%

SB

WB 1,003 -2%984

N. Nash Street and

WB Lee Hwy

NB 81 -27%

SB 28 -7%

59

26

1%

Intersection

1,205

1,446

90

8

-19

-43

0

4

4

-22

-2

-1%


N. Lynn Street and

Fairfax Drive

NB 1,224 2%

EB 137 1%

WB

138

121

1,504

1,245

-4%281 -13

21

1

-1

21

Intersection 3,086 1%N. Lynn St and 17th St

N.

1,080 1%

WB 570 -1%-5

N. Lynn Street and

Wilson Blvd

NB 1,436 2%

EB

N. Lynn St and 19th St

N.

NB 1,487 -3%

1,086

565

3,111 25

-50

-72

-93

24

6

WB 491 -15%


419

2,137



(vph)Difference (%)

Southbound


Difference (vph)

LT 18 21 3 17%TH 50 53 3 6%RT 60 62 2 3%LT 153 134 -19 -12%TH 32 35 3 9%RT 167 159 -8 -5%LT 34 43 9 26%TH 695 723 28 4%RT 5 2 -3 -60%

U-Turn 11 22 11 100%LT 24 22 -2 -8%TH 434 457 23 5%RT 108 85 -23 -21%

LT 5 5 0 0%RT 15 14 -1 -7%TH 149 148 -1 -1%RT 19 20 1 5%LT 14 13 -1 -7%TH 50 50 0 0%

LT 4 4 0 0%TH 202 204 2 1%RT 90 87 -3 -3%LT 536 528 -8 -1%TH 181 181 0 0%RT 60 59 -1 -2%LT 24 25 1 4%TH 96 96 0 0%RT 44 46 2 5%

LT 165 165 0 0%TH 4 3 -1 -25%RT 81 73 -8 -10%LT 77 55 -22 -29%TH 2 1 -1 -50%RT 150 107 -43 -29%LT 8 7 -1 -13%TH 89 87 -2 -2%RT 39 37 -2 -5%LT 6 6 0 0%TH 176 159 -17 -10%RT 2 2 0 0%

LT 58 67 9 16%TH 995 974 -21 -2%TH 514 492 -22 -4%RT 59 75 16 27%

21

22

23

24

25

-97 -12%

N. Kent Street and

Wilson Blvd

EB 1,053 1,041 -12 -1%

WB 573 567 -6 -1%

Intersection 1,626 1,608 -18 -1%

N. Kent Street and 19th St N.

NB 250 241 -9 -4%

SB 229 163 -66 -29%

EB 136 131 -5 -4%

WB 184 167 -17 -9%

Intersection 799 702

N. Meade St and EB

Arlington Blvd

NB 296 295 -1 0%

SB 777 768 -9 -1%

EB 164 167 3 2%

Intersection 1,237 1,230 -7 -1%

27 2%

N. Nash Street and Arlington

Blvd

NB 20 19 -1 -5%

EB 168 168 0 0%

WB 64 63 -1 -2%


N. Nash St and Wilson

Blvd

NB 128 136 8 6%

SB 352 328 -24 -7%

EB 734 768 34 5%

WB 577 586 9 2%




(vph)Difference (%)

Southbound


Difference (vph)

LT 2 2 0 0%TH 5 6 1 20%RT 38 36 -2 -5%LT 200 205 5 3%TH 1 1 0 0%RT 43 35 -8 -19%LT 30 24 -6 -20%TH 953 939 -14 -1%RT 12 12 0 0%LT 8 8 0 0%TH 528 531 3 1%RT 76 77 1 1%

LT 89 89 0 0%TH 59 60 1 2%TH 74 71 -3 -4%RT 42 44 2 5%TH 555 567 12 2%RT 64 69 5 8%

TH 47 48 1 2%RT 43 40 -3 -7%LT 51 48 -3 -6%TH 23 22 -1 -4%LT 101 100 -1 -1%TH 640 680 40 6%

26

27

36

N. Oak Street and

Clarendon Blvd

NB 90 88 -2 -2%

SB 74 70 -4 -5%

EB 741 780 39 5%

Intersection 905 938 33 4%

N. Arlington Ridge Road and Wilson

Blvd

NB 45 44 -1

883 900 17 2%

N. Oak Street and Wilson

Blvd

NB 148 149 1 1%

SB 116 115 -1 -1%

WB 619 636 17 3%

Intersection

WB 612 616 4 1%


-2%

SB 244 241 -3 -1%

EB 995 975 -20 -2%

-20 -1%

PM Volume Calibration (Freeways)

Volume Calibration (Freeways)

PM Peak Hour (5:00-6:00 PM)

Subtotal Total Percent Target Target Met0

0

9

21

Interchange TypeBalanced

Count(vph)

VISSIM Through-put (vph)

Difference(vph)

Difference(%)

Basic 2,438 2,395 -43 -2%Ramp 1,379 1,240 -139 -10%Weave 3,817 3,569 -248 -6%Ramp 1,644 1,530 -114 -7%Basic 2,173 2,017 -156 -7%Ramp 840 827 -13 -2%Merge 3,013 2,831 -182 -6%Ramp 907 906 -1 0%Basic 3,920 3,743 -177 -5%

Diverge 5,320 5,335 15 0%Ramp 3,132 3,136 4 0%Ramp 1,812 1,815 3 0%Ramp 1,320 1,334 14 1%Basic 2,188 2,167 -21 -1%Ramp 999 1,012 13 1%Weave 3,187 3,191 4 0%Ramp 934 925 -9 -1%Basic 2,253 2,267 14 1%

Diverge 1,847 1,844 -3 0%Ramp 614 607 -7 -1%Basic 1,233 1,235 2 0%Ramp 722 693 -29 -4%Weave 1,955 1,945 -10 -1%RampRamp 1,048 1,043 -5 0%RampRamp 439 448 9 2%Ramp 1,759 1,786 27 2%Ramp 1,232 1,225 -7 -1%Weave 2,991 3,009 18 1%Ramp 577 596 19 3%Basic 2,414 2,417 3 0%Ramp 827 768 -59 -7%Merge 3,241 3,172 -69 -2%Basic 1,611 1,627 16 1%RampBasicBasic 1,191 1,178 -13 -1%RampBasic 2,835 2,715 -120 -4%

See Wilson Blvd/Arlington Ridge Rd intersection

See Eastbound I-66 above

See I-66 Eastbound above

Off-ramp to GW PkwyOff-ramp to WB US 50

See I-66 Westbound above

On-ramp from NB GW Pkwy

See Westbound I-66 above

Off-ramp to EB I-66Off-ramp to SB GW Pkwy

On-ramp from WB I-66On-ramp from SB GW Pkwy

On-ramp from WB I-66 and SB GW Pkwy

Between Ramps

Route 110 Southbound

Route 110 Northbound

UpstreamOff-ramp to WB I-66

US 50 Westbound

Off-ramp to NB N Lynn St

Downstream (Wilson Blvd)Upstream (Wilson Blvd)On-ramp from I-66 EB

Downstream

Between RampsOn-ramp from SB Ft Myer Dr

Downstream

US 50 Eastbound

UpstreamOff-ramp to NB N Meade St

I-66 Westbound

I-66 Eastbound

Downstream

Between RampsOn-ramp from N Meade St

Between Ramps

On-ramp from NB Route 110Between Ramps

Off-ramp to WB Lee Hwy/Key Bridge

Off-ramp to WB US 50 and GW Pkwy

Between Ramps

On-ramp from EB US 50Downstream

Upstream

On-ramp from SB GW PkwyBetween Ramps

Between RampsOff-ramp to SB Route 110

Between Ramps

Segment

UpstreamOn-ramp from EB Lee Hwy

YesWithin ± 15% for ≥ 100 vph to < 300 vph



85%

Volume Criteria

Segments(n = 35)

Within ± 20% for < 100 vph

30 86%

PM Travel Time Calibration

Travel Time CalibrationTravel Time - PM Peak Period (4:30-6:30 PM)

Travel Time Criteria Subtotal Total Percent Target Target MetWithin ± 1 minute for routes with observed travel times that are less than 7 minutes

10

Within ± 15% for average observed travel time that are greater than 7 minutes

0

Field(MM:SS)

VISSIM(MM:SS)

Difference(MM:SS)

Difference(%)

100 04:11 03:19 -00:51 -21%

200 02:26 02:18 -00:08 -5%

300 04:02 04:05 00:02 1%

400 03:01 02:16 -00:45 -25%

500 03:46 03:52 00:06 2%

600 01:43 01:44 00:01 1%

700 02:26 01:35 -00:51 -35%

800 01:31 01:18 -00:13 -15%

900 00:49 00:46 -00:03 -5%

1000 00:43 00:36 -00:07 -17%

Routes(n = 10)

10 100% 85% Yes

Peak Period Travel Time

Westbound Arlington Boulevard(Roosevelt Bridge to N. Rolfe St)

Southbound Route 100(N. Arlington Ridge Rd to Memorial Ave)

Northbound Route 110(Memorial Ave to WB I-66)

Route

Arterial Routes

Freeway Routes

Segment ID

Eastbound I-66(EB Lee Hwy off-ramp to Roosevelt Bridge)

Eastbound Arlington Boulevard(N. Rolfe St to Roosevelt Bridge)

Northbound Lynn St(Arlington Blvd to George Washington Memorial Pkwy)Southbound Fort Myer Dr(George Washington Memorial Pkwy to Arlington Blvd)Eastbound Clarendon Blvd(N. Rhodes St to N. Arlington Ridge Rd)Westbound Wilson Blvd(N. Arlington Ridge Rd to N. Oak St)

Westbound I-66(Roosevelt Bridge to 21st St N. overpass)

PM Queue Length Calibration

Queue Length Calibration

PM Peak Period (4:30-6:30 PM)

Total Percent Target Target Met

Approaches(n = 18)

17 94% 85% Yes

Observed Max

Queue (feet)

VISSIM Max

Queue (feet)


Max Queue

Difference (feet)

Max Queue

Difference (%)

Field Conditions


Notes

915 1,295 282 380 42% YField and VISSIM queues extend

past EB Lee Hwy

1,120 1,270 287 150 13% YQueue spills back upstream into

Rosslyn core

1,040 1,101 1,035 61 6% Y Queue spills back to GWP

700 779 185 79 11% Y

VISSIM queue is contained in the off-ramp; reduced speeds were

observed for the I-66 mainline weave upstream of the ramp.

820 2,239 401 1,419 173% Y

Queuing and reduced speed back to N. Nash St. VISSIM queue length also includes queuing along Fort

Myer Dr back to Key Bridge

220 328 28 108 49% YAverage and maximum queues

contained in the block between 19th and Lee Hwy, as observed

240 441 23 201 84% N

VISSIM queue extends past N. Oak St, slightly longer than observed;

queue length dependent on gaps on N. Nash St for stop-controlled

vehicles to enter

660 334 41 -326 -49% YQueueing back to Fort Myer Dr, as

observed; queue broken up by closely spaced intersections

Queue CriteriaModeled queues qualitatively reflect the

impacts of observed queues (e.g., spillback from ramp intersections, turn bay, or

downstream intersection)

EB Key Blvd at N. Nash St

EB 19th St N. at N. Lynn St

NB N. Lynn St at Key Bridge

SB GW Parkway off-ramp to Key

WB I-66 off-ramp at N. Lynn St

EB Lee Hwy N. Lynn St

SB Fort Myer Dr at 19th St N.

Location

NB N. Lynn St at Fort Myer Dr/GW Parkway on-ramp

PM Queue Length Calibration

Observed Max

Queue (feet)

VISSIM Max

Queue (feet)


Max Queue

Difference (feet)

Max Queue

Difference (%)

Field Conditions


NotesLocation

550 525 96 -25 -5% Y Queue contained within block

560 520 87 -40 -7% YQueuing and reduced speeds

between N. Oak St and N. Lynn St

770 739 215 -31 -4% Y Queue fills block as observed300 226 49 -74 -25% Y Queueing back to N. Kent St

320 654 158 334 104% Y

Average queue representative of observed queue; sight distance is

limited in the field to capture the max queue.

840 540 76 -300 -36% YMaximum queue extends beyond

multiple upstream intersection to N. Lynn St

90 181 65 91 101% YAverage queue representative of observed queue; VISSIM includes

spillback into garage

240 423 38 183 76% YVISSIM queue includes WB Arlington

Blvd off-ramp

0 22 0 22 N/A Y Negligible queuing

0 0 0 0 N/A Y Negligible queuing

EB Arlington Blvd on-ramp from N. Meade St

EB Arlington Blvd off-ramp to N.

WB Wilson Blvd at Fort Myer Dr

EB Clarendon Blvd at N. Oak St

WB Wilson Blvd at N. Oak St

SB N. Moore St at Wilson Blvd

NB N. Lynn St at Fairfax Dr

NB N. Lynn St at Wilson Blvd

EB Wilson Blvd at N. Lynn St

EB Wilson Blvd at Fort Myer Dr

PM Bottleneck Calibration

4:30 PM 4:30 PM

5:00 PM 5:00 PM

5:30 PM 5:30 PM

6:00 PM 6:00 PM

6:30 PM 6:30 PM

7:00 PM 7:00 PM

7:30 PM 7:30 PM

4:30 PM 4:30 PM

5:00 PM 5:00 PM

5:30 PM 5:30 PM

6:00 PM 6:00 PM

6:30 PM 6:30 PM

7:00 PM 7:00 PM

7:30 PM 7:30 PM

Freeway Average Speed ComparisonEastbound I-66

VIS

SIM

SP

EE

D

VIS

SIM

SP

EE

D

OB

SE

RV

ED

SP

EE

D

OB

SE

RV

ED

SP

EE

D

Westbound I-66

D.C

.

Rou

te 1

10

US

50 R

amp

N S

cott

Stre

et

N L

ynn

Stre

et

D.C

.

Rou

te 1

10

US

50 R

amp

N S

cott

Stre

et

N L

ynn

Stre

et


7050 6040302010 0Average Speed (mph)

7050 6040302010


4:30 PM 4:30 PM

5:00 PM 5:00 PM

5:30 PM 5:30 PM

6:00 PM 6:00 PM

6:30 PM 6:30 PM

7:00 PM 7:00 PM

7:30 PM 7:30 PM

4:30 PM 4:30 PM

5:00 PM 5:00 PM

5:30 PM 5:30 PM

6:00 PM 6:00 PM

6:30 PM 6:30 PM

7:00 PM 7:00 PM

7:30 PM 7:30 PM

Freeway Average Speed Comparison

VIS

SIM

SP

EE

D

VIS

SIM

SP

EE

DO

BS

ER

VE

D S

PE

ED

OB

SE

RV

ED

SP

EE

D

Westbound Arlington BlvdEastbound Arlington Blvd

Roo

seve

ltB

ridge

N M

eade

Stre

et

N R

hode

sSt

reet

Roo

seve

ltB

ridge

N M

eade

Stre

et

N R

hode

sSt

reet


7050 6040302010


4:30 PM 4:30 PM

5:00 PM 5:00 PM

5:30 PM 5:30 PM

6:00 PM 6:00 PM

6:30 PM 6:30 PM

7:00 PM 7:00 PM

7:30 PM 7:30 PM

4:30 PM 4:30 PM

5:00 PM 5:00 PM

5:30 PM 5:30 PM

6:00 PM 6:00 PM

6:30 PM 6:30 PM

7:00 PM 7:00 PM

7:30 PM 7:30 PM

VIS

SIM

SP

EE

DO

BS

ER

VE

D S

PE

ED

Freeway Average Speed ComparisonNorthbound Route 110 Southbound Route 110

VIS

SIM

SP

EE

DO

BS

ER

VE

D S

PE

ED

Mem

oria

l Driv

e

I-66

I-66

Mem

oria

l Driv

e


7050 6040302010

Documents

Appendix E: VISSIM Model Calibration Summary · VISSIM (Version 9, Build 10) was used to develop the AM and PM existing conditions models of the Rosslyn transportation network. Vehicle,