Hunter Mill Road and Sunset Hills Road Study
Community Meeting #5Progress Update
September 15, 2016
Kristin CalkinsFairfax County Department of Transportation
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Presentation Agenda• Project Objectives• Summary of Prior Community Involvement• Review of Alternatives Considered • Traffic Analysis Results • Detailed Evaluation of a 5-leg Roundabout• Evaluation of Sunset Hills Road Relocation• Next Steps• Questions and Answers
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Project Objectives• Address existing congestion• Plan for future traffic• Address queuing along Hunter Mill Road and
Sunset Hills Road• Improve access to the Dulles Toll Road by
minimizing congestion• Maintain Hunter Mill Road’s character by
applying context sensitive solutions
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Project Study AreaIntersection ID Intersection
CurrentIntersection Control Type
1Hunter Mill Road at Sunrise Valley Drive
Signalized
2Hunter Mill Road at
DTR EB RampsSignalized
3Hunter Mill Road at
DTR WB RampsSignalized
4Hunter Mill Road at
Sunset Hills RoadSignalized
5Hunter Mill Road at
Crowell RoadUnsignalized
(All-Way Stop)
6Hunter Mill Road at Hunting Crest Lane
Unsignalized(Two-Way Stop)
7Hunter Mill Road at
Lake Fairfax ParkUnsignalized
(Two-Way Stop)
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6
5
4 32
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Project Background• Board of Supervisors authorized study as a follow-on study to
the Reston Phase I Plan Amendment• Meetings held on:
• December 8, 2014: Kick-Off • February 24, 2015: Existing & No-Build conditions and community
input on alternatives• May 20, 2015: Analysis Findings
• July 2015: Project put on hold at request of community to allow for new capacity analysis methodologies for roundabouts to be adopted by the Transportation Research Board
• Meeting held on: June 30, 2016: Roundabout capacity results
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Project ProcessKi
ck O
ff M
eetin
gEx
isting
Co
nditi
ons
Futu
re
Cond
ition
s
Com
mun
ity
Mee
ting #
2
Deve
lopm
ent o
f Al
tern
ative
s
Com
mun
ity
Mee
ting #
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Proj
ect p
ut
on H
old
Com
mun
ity
Mee
ting
#4
Anal
ysis
of
Alte
rnati
ves
Com
mun
ity
Mee
ting #
5
Sele
ction
of
Pref
erre
d Al
tern
ative
Final
Repo
rt
Com
mun
ity
Mee
ting #
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Inco
rpor
ation
into
Com
p Pl
an
24 MONTHS
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We are Here
Summary of Community Comments• Concern that traffic from Wiehle Avenue may be
diverted to Hunter Mill Road• Concern that the signal at Crowell Road may
increase delays in the off-peak• Maintain the character of Hunter Mill Road• Main goal of study is to improve Level of Service
(LOS) on Hunter Mill Road
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Summary of Community Comments (Cont.)• Roundabouts preferred at Dulles Toll Road ramps• Widen Hunter Mill Road from eastbound Dulles
Toll Road to Sunrise Valley Drive• Concern that improvements may attract more
development• Community wants an in-depth review of
roundabouts• There should be a mix and match of alternatives
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Alternatives Considered
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Crowell Road
Sunset Hills Road
Sunrise Valley Drive
Hunt
er M
ill R
oad
WB DTR
EB DTR
No-BuildCrowell Road
Sunset Hills Road
Sunrise Valley Drive
Hunt
er M
ill R
oad
WB DTR
EB DTR
Alt. 1ACrowell Road
Sunset Hills Road
Sunrise Valley Drive
Hunt
er M
ill R
oad
WB DTR
EB DTR
Alt. 1B
Roundabout
Signal Proffered
Alternatives Considered (Cont.)
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Crowell Road
Sunset Hills Road
Sunrise Valley Drive
Hunt
er M
ill R
oad
WB DTR
EB DTR
No-BuildCrowell Road
Sunset Hills Road
Sunrise Valley Drive
Hunt
er M
ill R
oad
WB DTR
EB DTR
Alt. 2Crowell Road
Sunset Hills Road
Sunrise Valley Drive
Hunt
er M
ill R
oad
WB DTR
EB DTR
Alt. 3
Signal Proffered
Alternatives Considered (Cont.)
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Crowell Road
Sunset Hills Road
Sunrise Valley Drive
Hunt
er M
ill R
oad
WB DTR
EB DTR
No-BuildCrowell Road
Sunset Hills Road
Sunrise Valley Drive
Hunt
er M
ill R
oad
WB DTR
EB DTR
Alt. 4ACrowell Road
Sunset Hills Road
Sunrise Valley Drive
Hunt
er M
ill R
oad
WB DTR
EB DTR
Alt. 4B
Signal Proffered
Traffic Analysis Results
Traffic Analysis:• Performed for both 2030 and 2050• Consistent with VDOT Policies and Procedures • Used new Roundabout Methodology
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New Roundabout Methodology• New research resulted in:
• Re-assessment of Roundabout Capacity Models for the Highway Capacity Manual
• New methodology (adopted January 2016) resulted in an approximate 10-12% increase in roundabout capacity
• New model prioritizes movements with higher volumes• Resulting in improved LOS for heavier movements and overall
LOS• This study is an operational assessment, not an engineering design.
Roundabouts generally have greater ROW impacts• The best operating roundabout might have a tradeoff of a larger ROW
footprint
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2030 Traffic Analysis
• Utilized Future Year Projections from the Reston Phase I Plan Amendment.
• Included development potential associated with development of the Reston Transit Station Areas.
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2030 Traffic Analysis Results
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Crowell Road
Sunrise Valley Drive
Hunt
er M
ill R
oad
WB DTR
EB DTR
No-BuildCrowell Road
Sunset Hills Road
Sunrise Valley Drive
Hunt
er M
ill R
oad
WB DTR
EB DTR
Alt. 1A (Roundabouts)Crowell Road
Sunrise Valley Drive
Hunt
er M
ill R
oad
WB DTR
EB DTR
Alt. 1B (Roundabouts)
Signal Proffered C C
D D
C E
C C
D D
E C
D D
B B
C D C D
B B
B D
C B
LOS: A, B, C
LOS: D
LOS: E
LOS: F
AM/PM LOS
Key for Levels of Service
Sunset Hills Road
Sunset Hills Road
24 sec./26 sec.
41 sec./53 sec.
29 sec./73 sec.
30 sec./25 sec.
38 sec./48 sec.
37 sec./18 sec.
45 sec./49 sec.
29 sec./47 sec.
17 sec./17 sec.
23 sec./12 sec.
14 sec./42 sec.
29 sec./47 sec.
17 sec./17 sec.
2030 Traffic Analysis Results
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Crowell Road
Sunrise Valley Drive
WB DTR
EB DTR
No-BuildCrowell Road
Sunset Hills Road
Sunrise Valley Drive
WB DTR
EB DTR
Alt. 2 (Signals)Crowell Road
Sunrise Valley Drive
WB DTR
EB DTR
Alt. 3 (Signals)
Signal Proffered C C
D D
C E
C C
D D
C C
C D
C C
D D
D C
D C
D D
C D
Sunset Hills Road
Sunset Hills RoadHu
nter
Mill
Roa
d
Hunt
er M
ill R
oad
Hunt
er M
ill R
oad
LOS: A, B, C
LOS: D
LOS: E
LOS: F
AM/PM LOS
Key for Levels of Service
22 sec./27 sec.
21 sec./45 sec.
55 sec./37 sec.
33 sec./31 sec.
39 sec./44 sec.
42 sec./34 sec.
19 sec./41 sec.
36 sec./35 sec.
35 sec./44 sec.
24 sec./26 sec.
41 sec./ 53 sec.
29 sec./73 sec.
30 sec./25 sec.
38 sec./48 sec.
B D
2030 Traffic Analysis Results
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Crowell Road
Sunrise Valley Drive
WB DTR
EB DTR
No-BuildCrowell Road
Sunset Hills Road
Sunrise Valley Drive
WB DTR
EB DTR
Alt. 4A (Roundabouts at Ramps)Crowell Road
Sunrise Valley Drive
WB DTR
EB DTR
Alt. 4B (Signals at Ramps)
Signal Proffered C C
D D
C E
C C
D D
C C
D D
B B
F F
E C
D C
C B
C D
Sunset Hills Road
Sunset Hills RoadHu
nter
Mill
Roa
d
Hunt
er M
ill R
oad
Hunt
er M
ill R
oad
LOS: A, B, C
LOS: D
LOS: E
LOS: F
AM/PM LOS
Key for Levels of Service
29 sec./47 sec.
45 sec./50 sec.
123 sec./143 sec.
29 sec./27 sec.
17 sec./17 sec.
23 sec./12 sec.
39 sec./32 sec.
66 sec./27 sec.
24 sec./26 sec.
41 sec./ 53 sec.
29 sec./73 sec.
30 sec./25 sec.
38 sec./48 sec.
2030 Traffic Analysis Summary
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LOS Standard = LOS D* Alt 2 in new location ** No Build includes the proffered signal at Crowell Road
IntersectionRoundabouts Signals Mix & Match
No Build Alt. 1A Alt. 1B Alt. 2 Alt. 3 Alt. 4A Alt. 4BOVERALL LOS AM (PM)
Hunter Mill Rd. @Crowell Rd. / Sunset Hills Rd. - - C (B) - D (C) - C (B)
Hunter Mill Rd. @Crowell Rd.** C (C) E (C) - C (C) - C (C) -
Hunter Mill Rd. @Sunset Hills Rd.* D (D) - - D (D) - - -
Hunter Mill Rd. @DTR WB Ramps & Sunset Hills Rd. - D (D) - - - D (D) -
Hunter Mill Rd. @DTR WB Ramps C (E) - B (D) C (D) B (D) - D (C)
Hunter Mill Rd. @DTR EB Ramps C (C) B (B) B (B) C (C) D (C) B (B) E (C)
Hunter Mill Rd. @Sunrise Valley Dr. D (D) C (D) C (D) D (D) C (D) F (F) C (D)
2050 Traffic Analysis Results
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Crowell Road
Sunrise Valley Drive
WB DTR
EB DTR
No-BuildCrowell Road
Sunset Hills Road
Sunrise Valley Drive
WB DTR
EB DTR
Crowell Road
Sunrise Valley Drive
WB DTR
EB DTR
Signal Proffered B C
C B
D C
E C
E D
F F
F F
D B
C C
F B
D B D B
D B
Sunset Hills Road
Sunset Hills RoadHu
nter
Mill
Roa
d
Hunt
er M
ill R
oad
Hunt
er M
ill R
oad
LOS: A, B, C
LOS: D
LOS: E
LOS: F
AM/PM LOS
Key for Levels of Service
50 sec./14 sec.
137 sec./58 sec.
82 sec./82 sec.
37 sec./13 sec.
104 sec./14 sec.
26 sec./35 sec.
37 sec./13 sec.
50 sec./14 sec.
17 sec./23 sec.
25 sec./17 sec.
42 sec./32 sec.
60 sec./21 sec.
58 sec./48 sec.
Alt. 1A (Roundabouts) Alt. 1B (Roundabouts)
2050 Traffic Analysis Results
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Crowell Road
Sunrise Valley Drive
WB DTR
EB DTR
No-BuildCrowell Road
Sunset Hills Road
Sunrise Valley Drive
WB DTR
EB DTR
Crowell Road
Sunrise Valley Drive
WB DTR
EB DTR
Signal Proffered B C
C B
D C
E C
E D
C B
D C
E C
C C
F C
E D
E D
E D
E C
Sunset Hills Road
Sunset Hills RoadHu
nter
Mill
Roa
d
Hunt
er M
ill R
oad
Hunt
er M
ill R
oad
LOS: A, B, C
LOS: D
LOS: E
LOS: F
AM/PM LOS
Key for Levels of Service
21 sec./14 sec.
71 sec./38 sec.
40 sec./29 sec.
58 sec./22 sec.
118 sec./24 sec.
34 sec./31 sec.
55 sec./22 sec.
59 sec./48 sec.57 sec./48 sec.
17 sec./23 sec.
25 sec./17 sec.
42 sec./32 sec.
60 sec./21 sec.
58 sec./48 sec.
Alt. 2 (Signals) Alt. 3 (Signals)
2050 Traffic Analysis Results
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Crowell Road
Sunset Hills Road
Sunrise Valley Drive
WB DTR
EB DTR
No-BuildCrowell Road
Sunset Hills Road
Sunrise Valley Drive
WB DTR
EB DTR
Crowell RoadSunset Hills Road
Sunrise Valley Drive
WB DTR
EB DTR
Signal Proffered B C
C B
D C
E C
E D
C B
F F
D B
D C
F B
F E
E C
D B
Hunt
er M
ill R
oad
Hunt
er M
ill R
oad
Hunt
er M
ill R
oad
LOS: A, B, C
LOS: D
LOS: E
LOS: F
AM/PM LOS
Key for Levels of Service
117 sec./57 sec.
22 sec./20 sec.
82 sec./82 sec.
37 sec./13 sec.
104 sec./14 sec.
39 sec./32 sec.
66 sec./27 sec.
50 sec./14 sec.
60 sec./21 sec.
42 sec./32 sec.
25 sec./17 sec.
17 sec./23 sec.
58 sec./48 sec.
Alt. 4A (Roundabouts at Ramps) Alt. 4B (Signals at Ramps)
2050 Traffic Analysis Summary
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IntersectionRoundabouts Signals Mix & Match
No Build Alt. 1A Alt. 1B Alt. 2 Alt. 3 Alt. 4A Alt. 4BOVERALL LOS AM (PM)
Hunter Mill Rd. @Crowell Rd. / Sunset Hills Rd. - - F (B) - F (C) - F (B)
Hunter Mill Rd. @Crowell Rd.** B (C) F (F) - C (B) - C (B) -
Hunter Mill Rd. @Sunset Hills Rd.* C (B) - - E (D) - - -
Hunter Mill Rd. @DTR WB Ramps & Sunset Hills Rd. - F (F) - - - F (F) -
Hunter Mill Rd. @DTR WB Ramps D (C) - C (C) D (C) C (C) - D (C)
Hunter Mill Rd. @DTR EB Ramps E (C) D (B) D (B) E (C) E (C) D (B) E (C)
Hunter Mill Rd. @Sunrise Valley Dr. E (D) D (B) D (B) E (D) E (D) F (E) D (B)
LOS Standard = LOS D* Alt 2 in new location ** No Build includes the proffered signal at Crowell Road
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Detailed Evaluation of 5-leg Roundabout • Intersection at Hunter Mill Road, Dulles
Toll Road (WB) and Sunset Hills Road• This evaluation is being done at the
request of the community• Designed per VDOT and FHWA standards• Evaluated for safe speeds, turning radii and
vehicle paths
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5-Leg Roundabout: Hunter Mill Defense League
5-Leg Roundabout Summary: Hunter Mill Defense League
• Design:– Utilized Bypass lanes to limit circle size– No impact on toll plaza
• Concerns– Additional conflict points due to bypass lanes– Not designed to VDOT standards – Requires widening under the bridge
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5-Leg Roundabout: Elongated Oval
5-Leg Roundabout Summary: Elongated OvalElongated Oval• Design:
– Minimized Impact on adjacent buildings– No impact on toll plaza
• Concerns– High speeds in circle– Reduced sight distance across circle– VDOT unlikely to approve design
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5-Leg Roundabout: Tight Circle
5-Leg Roundabout Summary: Tight CircleTightest Circle• Design
– Smallest total footprint allowable– Provides minimal change to existing facilities
• Concerns– Impacts Dulles Toll Road Ramp Plazas – would require relocation– Considerable right-of-way impacts on the east side of Hunter Mill Road– Approach angles violate NCHRP 672 guidance
• Would not be considered an allowable and constructible design
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5-Leg Roundabout: Feasible Design
5-Leg Roundabout Summary:Feasible DesignFeasible Design• Design is reflected in Alternatives 1A and 4A
– Only alternative that meets all VDOT and NCHRP design criteria– Minimizes impact on toll plaza
• Concerns– Impacts the Reston Presbyterian Church – Cultural and structural impacts associated with the design– Difficult Constructability
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5-Leg Roundabout: Alternatives 1A and 4A
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Sunset Hills Road Realignment
• Purpose of Sunset Hills Road Realignment:– To create distance from the Dulles Toll Road– To improve intersection efficiency along Hunter
Mill Road– Improve queuing conditions along Hunter Mill
Road
• Two potential alignments have been developed
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Realignment Option A
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Realignment Option B
Sunset Hills Realignment Summary• Option A
– Most natural geometry– Longest natural queuing area at Hunter Mill Road– Most separation to the Dulles Toll Road– Closest alignment to Hunting Crest neighborhood
• Option B– Utilizes more of the existing facility– Provides back access to parcels along Hunter Mill Road– Has unusual curvature on breakaway point from existing– Less queuing area along straightaway at Hunter Mill Road– Separates school and soccer field
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Next Steps • Evaluate Community Feedback• Review Analysis Results• Select a Preferred Alternative based on:
• Community Feedback• Traffic Analysis• Impacts • Select the Best Performing, Least Impactful Alternative
• Final Recommendations and Report• Public meeting to present preferred alternative
• Thursday, November 17 (Location TBD)
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Question & Answers
30 MinutesPlease limit yourself to one question so others
have an opportunity to ask
http://www.fairfaxcounty.gov/fcdot/huntermillstudy.htm