Reston Network Analysis: Existing Phasing Analysis and 2050 Tier 3

County of Fairfax, Virginia

Reston Network AnalysisExisting Phasing Analysis & 2050 Tier 3

August 8 & 10, 2016Advisory Group & Stakeholders Meeting

Kristin CalkinsFairfax County Department of Transportation


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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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• Prioritizatio

n of larger projects

Network Analysis Project Process

Advisory Group input, Stakeholder input, Community input


Phasing AnalysisExisting Conditions

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Existing Conditions Phasing Analysis

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• This process will help the prioritize roadway improvements in the Reston TSAs

• Based on greatest improvement in congestion compared the network without the project

• When Tier 3 is finalized a 2050 phasing analysis will be completed to determine long term importance



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Reston Phasing Analysis Projects

Grid of StreetsDTR Crossing at Soapstone Overpass – Sunrise Valley Dr to Sunset Hills RdDTR Town Center Parkway Underpass – Sunrise Valley Dr to Sunset Hills RdFox Mill Road Widening – Reston Parkway to Monroe StreetMonroe Street Widening – West Ox Road to Town of HerndonPinecrest Road Extension – South Lakes Dr to Sunrise Valley DrReston Parkway Widening – South Lakes Drive to DTRFairfax County Parkway - DTR to West Ox HOVFairfax County Parkway at Sunrise Valley Drive (Interchange)South Lakes Drive Overpass – Sunrise Valley Drive to Sunset Hills RdWest Ox Road Widening – Lawyers Road to Centreville RoadSunset Hills Road Widening – Fairfax County Parkway to Wiehle (6) and Wiehle to Hunter Mill Road (4)



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Phasing Analysis Process• The base year (2015) VISUM AM and

PM peak hour models were the starting point for the phasing analysis.

• Each planned improvement was added to the base year VISUM model.

• Vehicle hours travelled (VHT) were used to measure traffic congestion and benefit of each improvement.

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Results – Existing Phasing Analysis

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Improvement Ranking Hours of Delay w/ Project vs. Existing Conditions

Grid of Street Grid of Streets 1 -1,216

Town Center Town Center Parkway Underpass 2 -374

Soapstone Soapstone Overpass 3 -300

FCP/HOV Fairfax County Parkway - 6 lanes with High Occupancy Vehicle (HOV) lane(s) 4 -299

Sunset Hills Widen Sunset Hills Road – 6 lanes from Wiehle Ave to Fairfax County Pkwy, and 4 lanes from Wiehle Ave to Hunter Mill Road 5 -257

South Lakes South Lakes Overpass 6 -240

FCP/SRV Fairfax County Parkway and Sunrise Valley Drive Interchange 7 -184

Reston Pkwy Widen Reston Parkway - 6 lanes from South Lakes Drive to the DAAR 8 -82

Monroe Widen Monroe Street - 4 lanes from West Ox Road to the Town of Herndon 9 -27

Pinecrest Extend Pinecrest Road from South Lakes Drive to Sunrise Valley Drive 10 -2

Fox Mill Widen Fox Mill Road - 4 lanes from Reston Parkway to Monroe Street 11 0

West Ox Widen West Ox Road - 4 lanes from Lawyers Road to Centreville Road 12 28


Tier 3

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Mitigation Options• Mitigation Measures - Tiered Approach

– Tier 1: No right of way (ROW) impact – Tier 2: Some right of way impact– Tier 3: Large scale mitigations if needed

– Consultation with Advisory Group and Stakeholders

• Each grid link is initially assumed to be one lane in each direction (with bike/ped facilities as specified in the Comprehensive Plan)

– No turn lanes were initially assumed at new intersections

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2050 2nd Tier Problem Locations

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• Unmitigated had 22 Problem Locations• After Tier 1: 13 Problem Locations• After Tier 2: 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.


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2050 2nd Tier Problem Locations


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Network Analysis Follow-On Tasks

Fairfax County Pkwy. & Spring St.

Reston Pkwy. Capacity Improvements

Fairfax County Pkwy. & Sunrise Valley Dr.


Fairfax County Parkway & Spring Street

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FCP & Spring Street No Build

Lane Configuration & PM LOS

IntersectionNo-build LOS (PM)

Fairfax County Parkway & Spring Street Ramp B

Spring Street & Fairfax County Parkway Ramp F

Spring Street & Herndon Parkway C

Pros Cons• Improves conditions on Spring

Street and Herndon Parkway• Removes slip ramp to southbound

Fairfax County Parkway

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F

BFa

irbro

ok D

rive

Spring Street

FCP & Spring Street Option 1: Fairbrook Drive Ramp

Pros Cons• Maintains existing traffic patterns• Operating conditions are acceptable

• Geometry for ramp curvature will need to be investigated



Option 1 LOS (PM)

Fairfax County Parkway & Spring Street Ramp B B

Spring Street & Fairfax County Parkway Ramp F D

Spring Street & Herndon Parkway C C

Fairbrook Dr & Fairfax County Parkway Ramp - B17

D

B

B

Fairb

rook

Driv

e

Spring Street

FCP & Spring Street Option 2: Bi-Directional Ramp

Pros Cons• Eliminates traffic

signal along Fairfax County Parkway for improved operating conditions over no-build scenario

• Installation of a traffic signal on Spring Street on the west side of Fairfax County Parkway

• Construction of loop ramp requires large property takings

• Operating conditions at the new signalized intersection are at capacity during the AM peak hour.

• Creating a direct connection from the toll road may be confusing for drivers.



Option 2 LOS (PM)

Spring Street & Fairfax County Parkway Ramp F D


Sunset Hills Road & Fairfax County Parkway NB exit ramp - D

D

DFairb

rook

Driv

e

Spring Street

FCP & Spring Street Option 3: Ramp to NB FCP

Pros Cons• Eliminates traffic signal along Fairfax

County Parkway for improved operating conditions over No-build

• Smaller area of impact over loop ramps• Individual intersections provide for less

delay with all intersections operating at LOS D or better during the peak hours.

• Installation of a traffic signal on Spring Street on the west side of Fairfax County Parkway

• A new weave is created along Fairfax County Parkway between the Toll Road and Spring Street.



Option 3 LOS (PM)

Spring Street & Fairfax County Parkway Ramp F C


Sunset Hills Road & Fairfax County Parkway NB exit ramp - C

C

CFairb

rook

Driv

e

Spring Street


Fairfax County Parkway & Sunrise Valley Drive

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FCP & Sunrise Valley Drive No Build

Intersection No-build LOS (PM)

Fairfax County Parkway & Sunrise Valley Drive F

Pros Cons• Does not require construction or

new right-of-way• Travelers will experience delays in

excess of 100 seconds

No Build Assumes Fairfax County Parkway is Widened to 6 lanes

F

FCP & SRVD Option 1: Single Point Urban Interchange (SPUI)

Pros Cons• Provides improved operating

conditions over No-build • One signalized intersection• Queuing does not impact adjacent

intersections

• Large area of impact compared to a tight diamond for the approach ramps

• Larger crossing distances for pedestrians


Option 1 LOS (PM)

Fairfax County Parkway & Sunrise Valley Drive F D

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D

Fairfax County Parkway Bridge over Sunrise Valley Drive

FCP & SRVD Option 2: Tight Diamond Interchange

Pros Cons• Provides improved operating

conditions over No-build• Potentially smaller area of impact

over SPUI

• Queues impact adjacent intersections• Requires an additional signalized

intersection• Signal coordination between

intersections can be a concern and lead to vehicles getting “trapped” between intersections and creating additional delay


Option 2 LOS (PM)

Fairfax County Parkway & Sunrise Valley Drive F -

Fairfax County Parkway (NB) & Sunrise Valley Drive - D

Fairfax County Parkway (NB) & Sunrise Valley Drive - D23

DD

Fairfax County Parkway Bridge over Sunrise Valley Drive

Graphic is illustrative, intersections would be constructed closer together


Reston Parkway

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Reston Parkway

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• Option 1: Super Streets– Restricted left turns at:

• Spectrum Drive• Bowman Towne/Green Drive• New Dominion Parkway• Bluemont Way/Stratford Park Place• South Lakes Drive• Glade Drive• Fox Mill Road

– U-Turns at: • Between Bowman Towne Drive and Baron Cameron• Market Street/Stratford House Place• Sunrise Valley Drive• Between South Lakes Drive and Glade Drive• Between Glade Drive and Colts Neck Road• Colts Neck Road

• Option 2– Flyover from WB Sunset Hills Road to SB Reston Parkway– New Road connecting Lawyers Road to Fox Mill Road behind Park &

Ride


Bowman Towne Drive

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Reston Parkway Alternatives

Stratford House PlaceMarket Street

Baron Cameron Avenue

No-Build Super Street

New Dominion Parkway

*Pedestrian Signal

Bluemont Way

Sunset Hills Road

WB DTR

EB DTR

Bowman Towne Drive

Stratford House Place

Market Street


Convert to Median U-Turns

Bluemont Way

Sunset Hills Road

WB DTR

EB DTR

Dual WB Left Turns

Median U-Turns

No Left Turns

New Dominion Parkway No Left Turns

No Left Turns

Bowman Towne Drive


Market Street


Sunset Fly Over & Lawyers Bypass


*Pedestrian Signal

Bluemont Way

Sunset Hills Road

WB DTR

EB DTR

Dual WB Left Turns

WB Left Flyover Ramp


Colts Neck Road Colts Neck Road

Fox Mill RoadFox Mill Road

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Reston Parkway Alternatives (Cont.)No-Build

WB DTR

EB DTR

Sunrise Valley Drive

Right In/Right Out

South Lakes Drive

Glade Drive

Lawyers Road

WB DTR

EB DTR

Right In/Right Out

No Left Turns


South Lakes Drive

Glade Drive

Lawyers Road

NB U-Turn

No NB/SB Left Turns

Median U-Turns

Median U-Turns

U-Turns

No NB Lefts

Colts Neck Road

Fox Mill Road

WB DTR

EB DTR


Right In/Right Out

South Lakes Drive

Glade Drive

No NB Lefts

Super Street Sunset Fly Over & Lawyers Bypass


Bowman Towne Drive

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Reston Parkway LOS Results

Stratford House PlaceMarket Street


No-Build


*Pedestrian Signal

Bluemont Way

Sunset Hills Road

WB DTR

EB DTR

Bowman Towne Drive


Market Street


Median U-Turns

Bluemont Way

Sunset Hills Road

WB DTR

EB DTR

Dual WB Left Turns

Median U-Turns

No Left Turns

New Dominion Parkway No Left Turns

No Left Turns

Bowman Towne Drive


Market Street



*Pedestrian Signal

Bluemont Way

Sunset Hills Road

WB DTR

EB DTR

Dual WB Left Turns

WB Left Flyover Ramp

96 Seconds 66 Seconds 66 Seconds









13.7 Seconds


Colts Neck Road Colts Neck Road

Fox Mill RoadFox Mill Road

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Reston Parkway LOS Results (Cont.)No-Build

WB DTR

EB DTR


Right In/Right Out

South Lakes Drive

Glade Drive

Lawyers Road

WB DTR

EB DTR

Right In/Right Out

No Left Turns


South Lakes Drive

Glade Drive

Lawyers Road

NB U-Turn

No NB/SB Left Turns

Median U-Turns

Median U-Turns

U-Turns

No NB Lefts

Colts Neck Road

Fox Mill Road

WB DTR

EB DTR


Right In/Right Out

South Lakes Drive

Glade Drive

No NB Lefts







152 Seconds 159 Seconds 151 SecondsLawyers Road


5 Seconds

47 Seconds

25 Seconds


Reston Parkway Volumes

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• Reston Parkway is projected to carry similar volumes to Fairfax County Parkway (FCP)

2050 PM Peak Hour VolumesFairfax County

Pkwy Reston Pkwy Comparison


NB Approach 2071 1968 -103SB Approach 2586 2665 +79

Between DTR Ramps

NB 2510 2386 -124

SB 2775 3010 +235

Sunset Hills Road

NB Approach 2343 2543 +200

SB Approach 2062 2154 +92


NB Approach 2746 1650 -1096

SB Approach 1163 458 -705


Reston Parkway Take Away

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• Reston Parkway carries a significant portion of north/south traffic in the area

• At grade mitigation to LOS E is challenging• Grade separations are not appropriate for the

area’s character• Discuss possibility of accepting locations with

LOS F along Reston Parkway• Fairfax County Parkway improvements could

improve Reston Parkway


Next Steps• Advisory Group Meeting Monday, September 12• Tier 3 VISUM Analysis

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Schedule

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Task Description 2015 May 15 June 15 July 15 Aug 15 Sep 15 Oct 15 Nov 15 Dec 15 Jan 16 Feb 16 Mar 16 April 16 May 16 June 16 July 16 Aug 16 Sep 15 Oct 15 Nov 16 Dec 16 Jan 17

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) - Task complete advance to Tier 3 Mitigation

3A1 Analyze Future Conditions (2030)

3B Simulation of the Dulles Toll Road

4A Meetings/Presentations

5A Phasing Analysis - Existing Conditions- Ths Task is complete

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

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08/8/16


Discussion• Fairfax County Parkway & Spring Street

– Staff recommends Option 1• Fairfax County Parkway & Sunrise Valley Drive

– Alternatives are Comparable• Reston Parkway

– Discussion of alternatives and possible approach– Possible ideas on how to improve Reston Parkway

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Questions & Comments

For questions and comments about the study please contact:

Kristin Calkins: [email protected](703) 877-5710

http://www.fairfaxcounty.gov/fcdot/restonnetworkanalysis/

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Reston Network Analysis: Existing Phasing Analysis and 2050 Tier 3

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