This document summarizes the results of the 2050 2nd Tier Mitigation analysis for the Reston Network study. Key points include: - 26 new signalized intersections were recommended in the 1st Tier analysis. - The 2nd Tier analysis proposed additional signals, turn lanes, and through lanes to further reduce congestion. After these improvements, 9 intersections were still projected to operate at unacceptable delays. - Follow-on tasks were identified to study remaining problem locations, including the Fairfax County Parkway corridor and sections of Reston Parkway. 3rd Tier mitigations like alternative intersections may also be considered. - The analysis found reductions in the number of intersections exceeding delay thresholds after applying the tiered

1. County of Fairfax, Virginia
Reston Network Analysis
2050 2nd Tier Mitigation Results
March 28 & 30, 2016
Advisory Group & Stakeholders Group
Kristin Calkins
Fairfax County Department of Transportation

2. County of Fairfax, Virginia
Agenda
• Study Purpose
• Project Progress Overview
• 2050 2nd Tier Mitigation Results
• Next Steps
• Questions and Answers
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3. County of Fairfax, Virginia
Purpose of Study
• Conduct a detailed analysis of the grid of streets
to determine:
– 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
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4. 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

5. County of Fairfax, Virginia
Reston VISUM Model
Tysons
Reston
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6. County of Fairfax, Virginia
Mitigation
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7. County of Fairfax, Virginia
Purpose of Mitigation
• Mitigation reduces vehicle congestion
• Mitigation reduces delays experienced at
intersections
• Mitigation improves the reliability of travel times
through an area (for both buses and vehicles)
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8. County of Fairfax, Virginia
Mitigation Options
• Mitigation Measures - Tiered Approach
– 1st Tier: No right of way (ROW) impact
– 2nd Tier: Some right of way impact
– 3rd Tier: Large scale mitigations if needed
– Consultation with Advisory Group and
Stakeholders
• Each grid link is initially assumed to be one
lane in each direction
– No turn lanes were initially assumed at new
intersections
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9. County of Fairfax, Virginia
2050 1st Tier Mitigation Measures
• No ROW Impact Mitigation Measures
– Modifications to lane configurations
– Signal timing and phasing optimization
– All-way stop vs. two-way stop evaluation
– Additional traffic signals
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10. County of Fairfax, Virginia
Mitigation Measures (Cont.)
1st Tier: No Right of Way Impact
10
•Existing and Potential Future Signals
– Adding/removing traffic signals
– Adding/modifying stop control
– Modifying Parking
Westwood Center Dr. @
Sheraton Tysons Dr. (2015)
Westwood Center Dr. @
Sheraton Tysons Dr. (2013)

11. County of Fairfax, Virginia
2050 1nd Tier
Recommendations
11

12. County of Fairfax, Virginia
2050 1st Tier Signal Recommendations
12
26 New Signalized Intersection Locations
Sunrise Valley Dr. @ Wood Oak Dr. Sunrise Valley Dr. @ Commerce Park Dr. East
Sunrise Valley Dr. @ Colts Brook Dr. Soapstone Overpass @ Indian Ridge Rd. Extension
Frying Pan Rd. @ Greg Roy Ln. Sunset Hills Rd. @ West of Town Center Pkwy.
Monroe St. @ Future Connection to Herndon Metro Town Center Pkwy. @ North of Sunset Hills
Glade Dr. @ Pinecrest Rd. Town Center Pkwy. @ Market St.
South Lakes Dr. @ Pinecrest Rd. Sunset Hills Rd. @ Library St.
Sunrise Valley Dr. @ Pinecrest Rd. Extended Sunset Hills Rd. @ Soapstone Overpass
Sunrise Valley Dr. @ Town Center Pkwy. Sunset Hills Rd. @ East of Soapstone Overpass
Town Center Pkwy. @ North of Sunrise Valley Dr. Sunset Hills Rd. @ South Lakes Overpass
West of Reston Pkwy. with grid street Reston Station Blvd. @ Metro Center Dr.
Sunrise Valley Dr. @ Roland Clarke Place Reston Station Blvd. @ Michael Faraday Dr.
Sunrise Valley Dr. @ Indian Ridge Rd. Isaac Newton Square S. @ Isaac Newton Square W.
Sunrise Valley Dr. @ Commerce Park Dr. West Wiehle Ave. @ Isaac Newton Square N.

13. County of Fairfax, Virginia
Problem Locations After Tier 1 Mitigation
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• Unmitigated had 22 Problem Locations
• 13 intersections with delay over 120 Seconds:
1. Frying Pan Road & Sunrise Valley Drive
2. Frying Pan Road & Centreville Road
3. Centreville Road & Coppermine Road
4. Centreville Road & Sunrise Valley Drive
5. Monroe Street & Fox Mill Road
6. Spring Street & Herndon Parkway
7. Fairfax County Parkway & Baron Cameron Avenue
8. Fairfax County Parkway & Sunrise Valley Drive
9. Town Center Parkway & Sunset Hills Road
10. Reston Parkway & Baron Cameron Avenue
11. Reston Parkway & Bowman Towne Drive
12. Reston Parkway & Sunrise Valley Drive
13. Reston Parkway & South Lakes Drive

14. County of Fairfax, Virginia
2050 2nd Tier
Recommendations
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15. County of Fairfax, Virginia
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Mitigation Measures
2nd Tier: Some Right of Way Impact
• Additional signals where needed
• Turn lanes
– New Left and Right turn lanes
• Additional through lane
• Additional grid link

16. County of Fairfax, Virginia
2050 2nd Tier Recommendations
16
New Signals
• New Dominion Pkwy. & Library St.
• Reston Station Blvd. & Soapstone Dr.
• Bracknell Dr. & Stevenage Rd.
• Reston Town Center West consolidated access

17. County of Fairfax, Virginia
2050 2nd Tier Intersection Control
17
Existing Signal
Signal Proposed by
different study
Signal Proposed

18. County of Fairfax, Virginia
2050 2nd Tier Intersection Control (Cont.)
18
Existing Signal
Signal Proposed by
different study
Signal Proposed
Signal Proposed in
Tier 2

19. County of Fairfax, Virginia
2050 2nd Tier Recommendations
19
Turn Lanes
• Monroe St. & Frying Pan Rd./Fox Mill Rd.
• Reston Pkwy. & Sunrise Valley Dr.
• Sunset Hills Rd. &Town Center Pkwy.
• Wiehle Ave. & Reston Station Blvd.
• Wiehle Ave. & N Isaac Newton Sq.
There are still locations with turning
movements with delays in excess 120 seconds
that will be looked at for possible turn-lanes

20. County of Fairfax, Virginia
2050 2nd Tier Recommendations
New Turn Lanes (Cont.)
20
Monroe St & Frying Pan Rd/Fox Mill Rd – new WB right
turn laneTier 1 Tier 2
AM WB Right: LOS F
(145 sec.)
AM WB Right: LOS E
(55 sec.)

21. County of Fairfax, Virginia
2050 2nd Tier Recommendations
New Turn Lanes (Cont.)
21
Reston Pkwy. & Sunrise Valley Dr. – modified WB approach
Tier 1 Tier 2
AM: 142 sec. AM: 117 sec.

22. County of Fairfax, Virginia
2050 2nd Tier Recommendations
New Turn Lanes (Cont.)
22
Town Center Pkwy. & Sunset Hills Rd. - SB & NB left turn lanes
Tier 1 Tier 2
TownCenter
Pkwy.
Sunset Hills Rd. Sunset Hills Rd.
TownCenter
Pkwy.
AM: 106 sec.
PM: 157 sec.
AM: 41 sec.
PM: 40 sec.

23. County of Fairfax, Virginia
2050 2nd Tier Recommendations
New Turn Lanes (Cont.)
23
Wiehle Ave. & Reston Station Blvd.- WB left turn lane
Tier 1 Tier 2
AM WB approach:
121 sec.
AM WB approach:
60 sec.

24. County of Fairfax, Virginia
2050 2nd Tier Recommendations
New Turn Lanes (Cont.)
24
Wiehle Ave. & N. Isaac Newton Sq.- EB left turn lane & WB right turn lane
Tier 1 Tier 2
PM: 103 sec.
PM: 65 sec.

25. County of Fairfax, Virginia
2050 2nd Tier Recommendations
Town of Herndon
25
Comprehensive Plan Improvements
• Fairbrook Drive Extension
• Worldgate Drive Extension
Comp. Plan Turn Lanes
• Spring St. & Ramp to Fairfax County Pkwy.
• Spring St. & Herndon Pkwy.
• Monroe St. & Worldgate Dr.
• Monroe St. & Herndon Pkwy.
Comp. Plan New Signals
• Worldgate Dr. Extension & Herndon Pkwy.
• Herndon Pkwy. & Fairbrook Dr.

26. County of Fairfax, Virginia
2050 2nd Tier Recommendations
Town of Herndon Comprehensive Plan Improvements
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27. County of Fairfax, Virginia
2050 2nd Tier Recommendations
Town of Herndon Comprehensive Plan Improvements (cont.)
27
Spring St. &
Herndon Pkwy.
Spring St. & Ramp to
Fairfax County Pkwy.

28. County of Fairfax, Virginia
2050 2nd Tier Recommendations
Town of Herndon Comprehensive Plan Improvements (cont.)
28
Worldgate Dr. &
Herndon Pkwy.
Monroe St. &
Worldgate Dr.
Monroe St. &
Herndon Pkwy.

29. County of Fairfax, Virginia
2050 2nd Tier Mitigation
Results
29

30. County of Fairfax, Virginia
2050 2nd Tier Mitigation Results
• Stop Controlled Intersections:
– Overall LOS
– Overall delay
• Signalized Intersections:
– Overall LOS
– Overall delay
– LOS by movement
– Delay by movement
– Volumes for each movement
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31. County of Fairfax, Virginia
Level of Service Standard
• LOS E (55 – 80 seconds of delay) is the standard
for the Reston Transit Station Areas
• VDOT and FCDOT have agreed on LOS E as the
standard for the Reston Transit Station Areas
• Documentation of the agreement on LOS is
underway
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32. County of Fairfax, Virginia
2nd Tier LOS Results
• Of 42 key signalized intersections in the study area,
the following are forecast operate at Level of
Service F:
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42 Key Intersections – LOS F
2050
Unmitigated
After
2050 1st Tier
After
2050 2nd Tier
AM Peak Hour 24 12 10
PM Peak Hour 26 12 12
AM & PM Peak Hour 22 9 9

33. County of Fairfax, Virginia
2050 1st Tier Peak Hour LOS (Page 1)
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34. County of Fairfax, Virginia
2050 2nd Tier Peak Hour LOS (Page 1)
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35. County of Fairfax, Virginia
2050 1st Tier Peak Hour LOS (Page 2)
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36. County of Fairfax, Virginia
2050 2nd Tier Peak Hour LOS (Page 2)
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37. County of Fairfax, Virginia
2050 1st Tier Peak Hour LOS (Page 3)
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38. County of Fairfax, Virginia
2050 2nd Tier Peak Hour LOS (Page 3)
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39. County of Fairfax, Virginia
2050 Problem Locations
39
Intersections – 120+ Seconds of Delay
Peak Hour
2050
Unmitigated
After 2050
1st Tier
After 2050
2nd Tier
AM 17 12 8
PM 19 7 5
AM & PM 14 5 4
With signal re-timings and the introduction
of signals there has been a reduction in the
number of intersections experiencing delays
in excess of 120 seconds

40. County of Fairfax, Virginia
2050 1st Tier Problem Locations
40
Innovation
Grid is Finalized
Innovation &
Herndon TSAs

41. County of Fairfax, Virginia
2050 2nd Tier Problem Locations
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42. County of Fairfax, Virginia
2050 1st Tier Problem Locations (cont.)
42
Reston &
Wiehle TSAs

43. County of Fairfax, Virginia
2050 2nd Tier Problem Locations (cont.)
43
Reston &
Wiehle TSAs

44. County of Fairfax, Virginia
2050 2nd Tier Problem Locations
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• Unmitigated had 22 Problem Locations
• After 1st Tier: 13 Problem Locations
• After 2nd Tier: 9 Problem Locations
– 3 are in Innovation TSA which has already been
finalized
– 6 are associated with identified follow-on tasks
• Fairfax County Parkway & Spring Street
• Fairfax County Parkway & Sunrise Valley Drive
• Reston Parkway: From Lawyers Road to Baron Cameron
Ave.

45. County of Fairfax, Virginia
2050 2nd Tier Problem Locations
45
• Intersections with Delay over 120 Seconds
1. Centreville Road & Frying Pan Road
2. Centreville Road & McNair Farms Drive
3. Centreville Road & Sunrise Valley Drive
4. Fairfax County Parkway & Spring Street
5. Fairfax County Parkway & Sunrise Valley Drive
6. Reston Parkway & Baron Cameron Avenue
7. Reston Parkway & Bowman Towne Drive
8. Reston Parkway & Sunrise Valley Drive
9. Reston Parkway & South Lakes Drive
FollowonTask
Intersections
Innovation
Intersections

46. County of Fairfax, Virginia
46
Network Analysis Follow-On Tasks
Fairfax County
Pkwy. & Spring St.
Reston Pkwy.
Capacity Improvements
Fairfax County Pkwy.
& Sunrise Valley Dr.

47. County of Fairfax, Virginia
3rd Tier Mitigation
47

48. County of Fairfax, Virginia
Mitigation Measures
3rd Tier: Alternative Intersection Treatment
• Median U-Turn/Superstreet
– Eliminates left turn movement for side streets
– Increases thru movement green time
– Additional needed ROW to provide turn radius
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49. County of Fairfax, Virginia
Mitigation Measures
3rd Tier: Large Mitigation Measures
• Underpass/Overpass
– Provides for an uninterrupted thru movement
• Only done in close coordination with Advisory
Group and Stakeholders after all other mitigation
measures have not worked
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50. County of Fairfax, Virginia
Next Steps
• Review Tier 2 mitigations with interested parties
• Advisory Group on Funding – Monday, April 11
• Public Meeting – late April/early May
• Present Tier 3 mitigation measures
• Phasing Analysis
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51. County of Fairfax, Virginia
Schedule
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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
Sep-16 Oct-16Mar-16 Apr-16 May-16 Jun-16 Jul-16 Aug-16Feb-15May-15 Jun-15 Jul-15 Aug-15 Sep-15 Oct-15 Nov-15 Dec-15 Jan-16
3/28/16

52. County of Fairfax, Virginia
Questions & Comments
For questions and comments about the study please
contact:
Kristin Calkins: Kristin.Calkins@fairfaxcounty.gov
(703) 877-5710
http://www.fairfaxcounty.gov/fcdot/restonnetworkanalysis/
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