1. County of Fairfax, Virginia
Reston Network Analysis
Existing Conditions
Stakeholders Meeting
November 20, 2015
Kristin Calkins
Fairfax County Department of Transportation
2. County of Fairfax, Virginia
Agenda
• Project Overview
• Overview of Modeling Process
– Data Collection
– Modeling Methodology
– Analysis and Results
• Existing Conditions
• 2050 & 2030 Trip Reductions
• 2050 Model Runs
• Next Steps
• Questions And Answers
Department of Transportation
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3. County of Fairfax, Virginia
Reston Transportation Recommendations
Improvements from Reston Phase I Plan Amendment
• An Enhanced Street Network to increase connectivity
• Three additional Toll Road Crossings
– Town Center Parkway Underpass
– Soapstone Drive Overpass
– South Lakes Drive Overpass
• Grade Separate Fairfax County Parkway/Sunrise Valley
Drive
Department of Transportation
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4. County of Fairfax, Virginia
Enhanced Street Network
• Maintains a balance between land use and transportation
• Provide alternate routes through the TSAs for all modes
• Ensures pedestrian mobility & connectivity throughout
the Transit Station Areas (TSAs)
• Provides connectivity for bikes
• Support bus service to Metrorail
• Strengthened by a strong Transportation Demand
Management (TDM) program in the TSAs
Department of Transportation
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6. County of Fairfax, Virginia
Purpose of Study
• Conduct a detailed analysis of the grid of streets to
determine:
– Signal Control
– Number of lanes between and at intersections
– How to best serve pedestrians, bikes and transit
– Right-of-way needs
• Assign urban street types and modal emphasis based on
Department of Rail and Public Transportation Multimodal
System Design Guidelines
• Conduct a phasing analysis of when larger projects are
needed
Department of Transportation
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7. County of Fairfax, Virginia
Reston Network Analysis Tasks
1. Data Collection – done
2. Existing Conditions – being finalized
3. Future Conditions – coordination beginning
– Determine Grid of Streets
4. Phasing Analysis
5. DRPT Classifications
6. Specific location improvements for additional study
– Reston Parkway
– Sunrise Valley Drive @ Fairfax County Parkway
– Spring Street @ Fairfax County Parkway
– Rock Hill Road Bridge
Department of Transportation
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8. Data
Collection
• Traffic
Counts in
June 2015
• Travel Time
Runs
Existing
Conditions
• Capacity
Analysis
• Level of
Service
Test Grid of
Streets (2030
& 2050)
• Traffic
Forecasting
Capacity
Analysis
• Level of
Service
Mitigation
• Signal re-
timing
• New links
• Turn lanes
• Additional
lanes
Roadway
Classification
• DRPT Design
Guidelines
• Bike lanes
• Sidewalks/
Pedestrian
routes
• On-Street
Parking
• Transit Routes
Finalize Grid of
Streets (2030
& 2050)
Based on:
• Advisory Group
input
• Stakeholder
input
• Community
input
Phasing
Analysis
• Prioritization
of larger
projects
Network Analysis Project Process
Advisory Group input, Stakeholder input, Community input
9. County of Fairfax, Virginia
Data Needs
• Completed
– Intersections Turning Movement Counts (TMCs)
– Intersections for Queue Measurement
– Speed Run Routes
– Synchro input and output files
– Driveway Locations
– Future Grid of Street Plans
• Future
– Mitigation Plans
Department of Transportation
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10. County of Fairfax, Virginia
Data Needs – 7 Speed Run Routes
Department of Transportation
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11. County of Fairfax, Virginia
Data Needs – 40 TMC/20 Queue Lengths
Department of Transportation
12. County of Fairfax, Virginia
Data Needs – SYNCHRO Network
Department of Transportation
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13. County of Fairfax, Virginia
Data Inputs to VISUM Model Process
• MWCOG / Fairfax County Models
• GIS Layers (Traffic Analysis Zones; Parcels;
Aerial Imagery)
• Traffic Counts (Freeways & Arterials)
• Other Available Traffic Counts
• Traffic Signal Timings
• SYNCHRO for Signal Optimization
Department of Transportation
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14. County of Fairfax, Virginia
Modeling Flowchart Base Condition
MWCOG 2.3
Fairfax County
TDM
(
Reston Meso
Model VISUM)
Update
Time
VISSIM
SYNCHRO
GIS
Slicing 30 min
TAZ Disagg
Department of Transportation
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15. County of Fairfax, Virginia
Modeling Flowchart Future Condition
Update
Time
MWCOG 2.3
Fairfax County
TDM
)
Slicing 30 min
TAZ Disagg
ITE TG
TOD credit
Land Use
(
Reston Meso
Model VISUM)
VISSIM
SYNCHRO
GIS
Department of Transportation
16. County of Fairfax, Virginia
Methodology
• County Model
– Seed trip tables
• VISUM
– Model development at mesoscopic (local roadway system
& driveway ) level.
• VISUM model input
– Traffic volumes and O-D trip tables
– SYNCHRO for signal timing optimization
• VISUM model output
– Seamlessly translated to the VISSIM simulation model at
the microscopic (roadway intersection) level.
• VISSIM model – DTR Only
– Microscopic analyses – adds intersection and driveway
level details
Department of Transportation
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17. County of Fairfax, Virginia
Land Use & Transportation
• Test transportation improvements needed to support the
land use potential approved in the Reston Phase I
Comprehensive Plan
Department of Transportation
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18. County of Fairfax, Virginia
MWCOG Regional Model
Tyson
sReston
Department of Transportation
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19. County of Fairfax, Virginia
Reston VISUM Model
Tysons
Reston
Department of Transportation
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20. County of Fairfax, Virginia
TAZ Zonal Split – Block Level
Department of Transportation
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21. County of Fairfax, Virginia
TAZ Zonal Split – Driveway Entrances
Department of Transportation
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22. County of Fairfax, Virginia
Base Calibration Procedure
Network Model
Demand Matrix
Assignment
TFlowFuzzy
Count Data
VISSIM
Department of Transportation
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23. County of Fairfax, Virginia
Calibration Parameter/Procedure
• VISUM/VISSIM
– Field Observed Volume
– Field Observed Queue
– Field Observed Corridor Travel Time
• VISSIM (DTR only)
– VDOT Traffic Operation Tool Guidebook
– Formula
– Number of Model Runs
– Confidence Level
– Tolerance Level
Department of Transportation
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24. County of Fairfax, Virginia
Analysis and Results
• Measure of Effectiveness (MOE) from VISSIM
– Field Observed vs. Model Volume
– Field Observed vs. Model Queue
– Field Observed vs. Model Corridor Travel Time
• Measure of Effectiveness (MOE) from VISUM
– Network Wide R2 Value
– Field Observed vs. Model Volume
– Intersection LOS
Department of Transportation
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25. County of Fairfax, Virginia
VISSIM Results
Department of Transportation
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26. County of Fairfax, Virginia
Dulles Toll Road AM Mainline Volumes
0
2000
4000
6000
8000
7:00-8:00 6:00-9:00
WB DTR Mainline east of Route 28
split
Field Vissim
0
5000
10000
15000
7:00-8:00 6:00-9:00
WB DTR Mainline east of Hunter Mill
Road off ramp
Field Vissim
0
5000
10000
15000
20000
7:00-8:00 6:00-9:00
EB DTR Mainline east of
Route 28/Airport merge
Field Vissim
0
5000
10000
15000
20000
25000
7:00-8:00 6:00-9:00
EB DTR Mainline east of Hunter Mill
Road on ramp
Field Vissim
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27. County of Fairfax, Virginia
Dulles Toll Road Exit Ramp Queues
7:00 AM – 8:00 AM
ID Westbound Exit Ramp
VISSIM
Volume
Field
Volume
GEH
VISSIM Max
Queue
Field Max Queue Ramp
Length
(ft)
Vehicle
s
Feet
Vehicle
s
Feet
2 Centreville Road & DTR WB ramps 703 700 0.1 12 298 15 375 1460
16
Fairfax County Parkway & WB DTR
ramps
552 575 1.0 7 167 6 150 1315
27 Reston Parkway & WB DTR ramps 717 815 3.5 8 190 7 175 1700
36 Wiehle Avenue & WB DTR ramps 312 405 4.9 8 195 9 225 1175
40 Hunter Mill Road & WB DTR ramps 354 360 0.3 11 251 8 200 1520
ID Eastbound Exit Ramp
VISSIM
Volume
Field
Volume
GEH
VISSIM Max
Queue
Field Max Queue Ramp
Length
(ft)
Vehicle
s
Feet
Vehicle
s
Feet
3 Centreville Road & DTR EB ramps 397 450 2.6 12 282 11 275 1515
17
Fairfax County Parkway & EB DTR
ramps
919 875 1.5 22 539 9 225 1230
28 Reston Parkway & EB DTR ramps 521 540 0.8 10 240 5 125 1160
37 Wiehle Avenue & EB DTR ramps 680 535 5.9 14 332 17 425 850
41 Hunter Mill Road & EB DTR ramps 355 360 0.3 15 352 5 125 975
Department of Transportation
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28. County of Fairfax, Virginia
Dulles Toll Road AM Travel Times
Direction Field VISSIM Difference
Westbound 06:33 05:44 -00:49
Eastbound 08:32 08:30 00:03
Centreville Road – Hunter Mill Road
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29. County of Fairfax, Virginia
Dulles Toll Road AM Animation
Department of Transportation
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30. County of Fairfax, Virginia
Dulles Toll Road PM Mainline Volumes
0
5000
10000
15000
20000
17:00-18:00 16:00-19:00
WB DTR Mainline east of Route 28
split
Field Vissim
0
5000
10000
15000
20000
25000
17:00-18:00 16:00-19:00
WB DTR Mainline east of Hunter Mill
Road off ramp
Field Vissim
0
2000
4000
6000
8000
10000
17:00-18:00 16:00-19:00
EB DTR Mainline east of
Route 28/Airport merge
Field Vissim
0
5000
10000
15000
17:00-18:00 16:00-19:00
EB DTR Mainline east of Hunter Mill
Road on ramp
Field Vissim
Department of Transportation
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32. County of Fairfax, Virginia
Dulles Toll Road PM Travel Times
Direction Field VISSIM Difference
Westbound 07:00 7:24 00:24
Eastbound 05:26 05:49 00:23
Centreville Road – Hunter Mill Road
Department of Transportation
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33. County of Fairfax, Virginia
Dulles Toll Road PM Animation
Department of Transportation
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34. County of Fairfax, Virginia
VISUM Results
Department of Transportation
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35. County of Fairfax, Virginia
Link Base Confidence Level
AM Peak (7:00 – 8:00) Area-wide
Department of Transportation
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36. County of Fairfax, Virginia
Link Base Confidence Level
PM Peak (5:00 – 6:00) Area-wide
Department of Transportation
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37. County of Fairfax, Virginia
Turning Movement Confidence Level
AM Peak (7:00 – 8:00) Area-wide
Department of Transportation
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38. County of Fairfax, Virginia
Turning Movement Confidence Level
PM Peak (5:00 – 6:00) Area-wide
Department of Transportation
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39. County of Fairfax, Virginia
0
2000
4000
6000
8000
10000
12000
Field Count vs. Assigned Volumes
EB DTR Mainline & Ramps (7:00 - 8:00 AM)
Field Count (7:00-8:00 AM)
Assignment Volumes (7:00-8:00 AM)
Department of Transportation
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40. County of Fairfax, Virginia
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
Field Count vs. Assigned Volumes
WB DTR Mainline & Ramps (5:00 - 6:00 PM)
Field Count (5:00 - 6:00 PM)
Assignment Volumes (5:00 - 6:00 PM)
Department of Transportation
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41. County of Fairfax, Virginia
0
500
1000
1500
2000
2500
3000
Fox Mill
Road
Sunrise
Valley Drive
South of
DTR EB
Ramps
Between
DTR
Ramps
North of
DTR WB
Ramps
Ramp to
Spring
Street
New
Dominion
Parkway
Baron
Cameron
Avenue
Field Count vs. Assigned Volumes
NB Fairfax County Pkwy (7:00 - 8:00 AM)
Field Count (7:00-8:00 AM)
Assignment Volumes (7:00-8:00 AM)
Department of Transportation
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42. County of Fairfax, Virginia
0
500
1000
1500
2000
2500
3000
Baron
Cameron
Avenue
New
Dominion
Parkway
Ramp to
Spring
Street
Fairfax
County
Pkwy SB -
North of
DTR WB
Ramps
Fairfax
County
Pkwy SB -
between
DTR
Ramps
Fairfax
County
Pkwy SB -
South of
DTR EB
Ramps
Sunrise
Valley
Drive
Fox Mill
Road
Field Count vs. Assigned Volumes
SB Fairfax County Pkwy (5:00 - 6:00 PM)
Field Count (5:00 - 6:00 PM)
Assignment Volumes (5:00 - 6:00 PM)
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43. County of Fairfax, Virginia
0
500
1000
1500
2000
2500
Field Count vs. Assigned Volumes
NB Reston Pkwy (7:00 - 8:00 AM)
Field Count (7:00-8:00 AM)
Assignment Volumes (7:00-8:00 AM)
Department of Transportation
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44. County of Fairfax, Virginia
0
500
1000
1500
2000
2500
3000
3500
Field Count vs. Assigned Volumes
SB Reston Pkwy (5:00 - 6:00 PM)
Field Count (5:00 - 6:00 PM)
Assignment Volumes (5:00 - 6:00 PM)
Department of Transportation
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45. County of Fairfax, Virginia
Existing Conditions
Department of Transportation
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46. County of Fairfax, Virginia
Existing Intersection LOS
Individual Movements may have a lower Level of Service
Department of Transportation
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47. County of Fairfax, Virginia
Existing Intersection LOS (Cont’d)
Individual Movements may have a lower Level of Service
Department of Transportation
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48. County of Fairfax, Virginia
Existing Intersection LOS (Cont’d)
Individual Movements may have a lower Level of Service
Department of Transportation
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49. County of Fairfax, Virginia
Existing Wiehle-Reston East Walkshed
Department of Transportation
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50. County of Fairfax, Virginia
Existing Reston Town Center Walkshed
Department of Transportation
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51. County of Fairfax, Virginia
Existing Herndon Walkshed
Department of Transportation
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52. County of Fairfax, Virginia
Existing Reston TSA Walk-shed
Department of Transportation
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53. County of Fairfax, Virginia
Development
Peak Hour – Future Trips
0-1/4 Mile ¼ to ½ Mile
Beyond ½
Mile
2030 2050 2030 2050 2030 2050
Office 40% 45% 35% 40% 30% 35%
Residential 40% 45% 35% 40% 20% 25%
Technological
Advancement for all Trips
- 7.5% - 7.5% - 7.5%
TDM Vehicle Trip Reduction Goals
Reductions based off of ITE Trip Generation Rates
Department of Transportation
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54. County of Fairfax, Virginia
Information Available at Request
• 2030 Land use
• 2050 Land use
• 2050 Grid - # lanes
• 2014 Trip Generation
• 2030 Trip Generation
• 2050 Trip Generation
Department of Transportation
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55. County of Fairfax, Virginia
2050 Model Runs
• Test 2050 Comp Plan Build Out
• Mitigation Measures - Tiered Approach
• No right of way impact
– Trip Re-assignment
– Optimize Signal Timing and Phasing
– Modify the Lane Configuration
– Evaluate 4-way Stop vs. 2-way Stop
– Traffic Signal Addition
• Some right of way impact
– Turn lanes
– Additional through lane
– Additional grid link
• Large scale mitigations if needed
– Discussion with Advisory Group and Stakeholders Group
Department of Transportation
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56. County of Fairfax, Virginia
Next Steps
• 2030 Model Runs
• DRPT Guidelines Roadway Classification
• Phasing Analysis
• Reston Comprehensive Plan Amendment
• If needed to integrate finalized grid of streets
• Four Specific Study Locations
• Reston Parkway
• Fairfax County Parkway at Spring Street
• Fairfax County Parkway at Sunrise Valley Drive
• Rock Hill Bridge
Department of Transportation
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57. County of Fairfax, Virginia
Schedule
Department of Transportation
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Task Description
1A Land Use and Networks - Task is Complete
1B Traffic Counts - Task is Complete
2A Establish Existing Conditions - Task is Complete
2B Calibrate Against Existing Conditions - Task is Complete
3A2 Analyze Future Conditions (2050)
3A1 Analyze Future Conditions (2030)
3B Simulation of the Dulles Toll Road
3C Microsimulation - Optional
4A Meetings/Presentations
5A Phasing Analysis - Existing Conditions
5B Phasing Analysis - 2050 - Optional
6 Determination of DRPT Guidelines Roadway
Classification
7 Documentation
8 Reston Parkway Capacity Improvements
9 Fairfax County Parkway & Spring Street Interchange
10 Fairfax County Parkway & Sunrise Valley Drive
11 Rock Hill Bridge at Sunrise Valley Drive
12A Meetings/Presentations
Feb-15May-15 Jun-15 Jul-15 Aug-15 Sep-15 Oct-15 Nov-15 Dec-15 Jan-16 Sep-16 Oct-16Mar-16 Apr-16 May-16 Jun-16 Jul-16 Aug-16
11/17/15
58. County of Fairfax, Virginia
Questions & Comments
For questions and comments about the study please
contact:
Kristin Calkins: Kristin.Calkins@fairfaxcounty.gov
(703) 877-5710
Department of Transportation
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Notas do Editor
The intent of this slide is to provide an overview of how the various models used in this process related to each others. Each model will be able to ‘talk’ back and forth with each other. Therefore, the data produced by one model is not a one-way linear process. For instance, the VISUM models can be used to produce data that can be used in the Fairfax County model.
The intent of this slide is to provide an overview of how the various models used in this process related to each others. Each model will be able to ‘talk’ back and forth with each other. Therefore, the data produced by one model is not a one-way linear process. For instance, the VISUM models can be used to produce data that can be used in the Fairfax County model.
As noted, VISUM is the primary tool used in this exercise. It accounts for the transportation network changes– and is directly compatible with the VISSIM microsimulation analysis.
The model is capable of estimating re-routing or diversion that may be experienced by the changing / addition of transportation network linkages.
This is an overview of the entire MWCOG model. The entire model is heavily concentrated in the Metro Washington area which includes a great level of detail in Fairfax County. The red polygon shoes the full extent of the VISUM model while the smaller red polygon represents the Tysons East study area.
This is a “zoomed-in” version of the last slide. The red polygon shows the full extent of the VISUM network. The blue lines are network links for the MWCOG / County model. The smaller stub links represent “centroid connectors” which represent access from the traffic analysis zones to the transportation network.
In order to better represent the land use changes in the VISUM model, traffic analysis zones (TAZs) in the MWCOG / County model will be split. The yellow lines represent the current TAZs. The orange lines represent the zone splits. The slide show provides an example of how one particular zone will be split into three zones.
The benefit of splitting zones enables the model to include a higher level of detail for driveway and access points. If the zones were not split, the traffic assignment at the driveways would appear more “lumpy” and would account for realistic distribution of trips to each access point.
Fuzzy logic began with the 1965 proposal of fuzzy set theory by Lotfi Zadeh.[2][3] The fuzzy logic has been applied to many fields, from control theory to artificial intelligence,
O/D trip tables are adjusted to match field count via a loop feed back process, shown in next slide.
Rules are usually expressed in the form:IF variable IS property THEN action
For example, a field observed screen Link Volume as a regulator to adjust that O/D at entry point might look like this:
IF Link Trip Production IS same as Link Volume THEN No AdjustmentIF Link Trip Production IS Greater Link Volume THEN decrease Trip ProductionIF Link Trip Production IS Less Than Link Volume THEN increase Trip Production
The results from VISUM include many of the results you might obtain from a microsimulation analysis (minus queues). For instance, a LOS based on Highway Capacity Manual can be calculated in addition to other system results.
The results from VISUM include many of the results you might obtain from a microsimulation analysis (minus queues). For instance, a LOS based on Highway Capacity Manual can be calculated in addition to other system results.
The results from VISUM include many of the results you might obtain from a microsimulation analysis (minus queues). For instance, a LOS based on Highway Capacity Manual can be calculated in addition to other system results.
The results from VISUM include many of the results you might obtain from a microsimulation analysis (minus queues). For instance, a LOS based on Highway Capacity Manual can be calculated in addition to other system results.