Hunter Mill Road and Sunset Hills Road Study: Community Meeting #5 - Sept. 15, 2016

1. Hunter Mill Road and Sunset Hills
Road Study
Community Meeting #5
Progress Update
September 15, 2016
Kristin Calkins
Fairfax County Department of Transportation

2. 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
2

3. 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
3

4. Project Study Area
4
Intersection ID Intersection
Current
Intersection
Control Type
1
Hunter Mill Road at
Sunrise Valley Drive
Signalized
2
Hunter Mill Road at
DTR EB Ramps
Signalized
3
Hunter Mill Road at
DTR WB Ramps
Signalized
4
Hunter Mill Road at
Sunset Hills Road
Signalized
5
Hunter Mill Road at
Crowell Road
Unsignalized
(All-Way Stop)
6
Hunter Mill Road at
Hunting Crest Lane
Unsignalized
(Two-Way Stop)
7
Hunter Mill Road at
Lake Fairfax Park
Unsignalized
(Two-Way Stop)
7
6
5
43
2
1

5. 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
5

6. Project Process
24 MONTHS
6
We are Here

7. 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
7

8. 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
8

9. Alternatives Considered
9
Crowell Road
Sunset Hills Road
Sunrise Valley Drive
HunterMillRoad
WB DTR
EB DTR
No-Build
Crowell Road
Sunset Hills Road
Sunrise Valley Drive
HunterMillRoad
WB DTR
EB DTR
Alt. 1A
Crowell Road
Sunset Hills Road
Sunrise Valley Drive
HunterMillRoad
WB DTR
EB DTR
Alt. 1B
Roundabout
Signal Proffered

10. Alternatives Considered (Cont.)
10
Crowell Road
Sunset Hills Road
Sunrise Valley Drive
HunterMillRoad
WB DTR
EB DTR
No-Build
Crowell Road
Sunset Hills Road
Sunrise Valley Drive
HunterMillRoad
WB DTR
EB DTR
Alt. 2
Crowell Road
Sunset Hills Road
Sunrise Valley Drive
HunterMillRoad
WB DTR
EB DTR
Alt. 3
Signal Proffered

11. Alternatives Considered (Cont.)
11
Crowell Road
Sunset Hills Road
Sunrise Valley Drive
HunterMillRoad
WB DTR
EB DTR
No-Build
Crowell Road
Sunset Hills Road
Sunrise Valley Drive
HunterMillRoad
WB DTR
EB DTR
Alt. 4A
Crowell Road
Sunset Hills Road
Sunrise Valley Drive
HunterMillRoad
WB DTR
EB DTR
Alt. 4B
Signal Proffered

12. Traffic Analysis Results
Traffic Analysis:
• Performed for both 2030 and 2050
• Consistent with VDOT Policies and Procedures
• Used new Roundabout Methodology
12

13. 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
13

14. 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.
14

15. 2030 Traffic Analysis Results
15
Crowell Road
Sunrise Valley Drive
HunterMillRoad
WB DTR
EB DTR
No-Build
Crowell Road
Sunset Hills Road
Sunrise Valley Drive
HunterMillRoad
WB DTR
EB DTR
Alt. 1A (Roundabouts)
Crowell Road
Sunrise Valley Drive
HunterMillRoad
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.

16. 2030 Traffic Analysis Results
16
Crowell Road
Sunrise Valley Drive
WB DTR
EB DTR
No-Build
Crowell 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 RoadHunterMillRoad
HunterMillRoad
HunterMillRoad
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

17. 2030 Traffic Analysis Results
17
Crowell Road
Sunrise Valley Drive
WB DTR
EB DTR
No-Build
Crowell 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 RoadHunterMillRoad
HunterMillRoad
HunterMillRoad
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.

18. 2030 Traffic Analysis Summary
18
LOS Standard = LOS D
* Alt 2 in new location
** No Build includes the proffered signal at Crowell Road
Intersection
Roundabouts Signals Mix & Match
No Build Alt. 1A Alt. 1B Alt. 2 Alt. 3 Alt. 4A Alt. 4B
OVERALL 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)

19. 2050 Traffic Analysis Results
19
Crowell Road
Sunrise Valley Drive
WB DTR
EB DTR
No-Build
Crowell 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 RoadHunterMillRoad
HunterMillRoad
HunterMillRoad
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)

20. 2050 Traffic Analysis Results
20
Crowell Road
Sunrise Valley Drive
WB DTR
EB DTR
No-Build
Crowell 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 RoadHunterMillRoad
HunterMillRoad
HunterMillRoad
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)

21. 2050 Traffic Analysis Results
21
Crowell Road
Sunset Hills Road
Sunrise Valley Drive
WB DTR
EB DTR
No-Build
Crowell 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
HunterMillRoad
HunterMillRoad
HunterMillRoad
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)

22. 2050 Traffic Analysis Summary
22
Intersection
Roundabouts Signals Mix & Match
No Build Alt. 1A Alt. 1B Alt. 2 Alt. 3 Alt. 4A Alt. 4B
OVERALL 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

23. 23
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

24. 24
5-Leg Roundabout: Hunter Mill Defense League

25. 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
25

26. 26
5-Leg Roundabout: Elongated Oval

27. 5-Leg Roundabout Summary: Elongated Oval
Elongated 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
27

28. 28
5-Leg Roundabout: Tight Circle

29. 5-Leg Roundabout Summary: Tight Circle
Tightest 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
29

30. 30
5-Leg Roundabout: Feasible Design

31. 5-Leg Roundabout Summary:Feasible Design
Feasible 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
31

32. 32
5-Leg Roundabout: Alternatives 1A and 4A

33. 33
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

34. 34
Realignment Option A

35. 35
Realignment Option B

36. 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
36

37. 37
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)

38. 38
Question & Answers
30 Minutes
Please limit yourself to one question so others
have an opportunity to ask
Kristin.Calkins@Fairfaxcounty.gov
http://www.fairfaxcounty.gov/fcdot/huntermillstudy.htm