Thinking Inside the Box: Best Practies on an Innovation to Improve Traffic Intersections

1. Bike Boxes
in San Francisco
ProWalk/ProBike
9 | 14 | 2010 | Chattanooga, TN

2. San Francisco in Context
• 2nd highest population
density in the U.S.
• 47 square miles
• Mild climate
• Population ~ 815,000
• Hilly (steepest hill 31.5%)

3. Bike Network in 2012
Increase to 79 miles (126 km) of bike lanes
Increase to 98 miles (157 km) of streets with sharrows
Downtown

4. Cycling Volumes in San Francisco
53% increase in cycling between 2006-2009

5. Ultimate Goal – A Positive Feedback Loop
More bike More demand
facilities (to accommodate bikes)
MORE CYCLISTS
More awareness Increase
of cyclists safety

6. San Francisco Practice
• Current Use
– Help cyclists merge to
left-side of road
• Bike Box Design
– Limit line (24” wide, 6’-
12’ before crosswalk)
– Bicycle symbol
– “No Turn on Red” at
signalized intersections
– “Stop Here on Red,
Except Bicycles”

7. Scott Bike Box Celebration

8. Scott-Oak Bike Box
• Help cyclists enter the left-turn only bike lane
• Scott Street
– 2 lane, two-way street with bike lane
– Bike left-turn only lane onto Fell Street bike lane

9. Scott/Oak Bike Box: Timeline
• May 2006
• Northbound bike lane and bike box installed
• December 2009
• Bike box painted green (no bike symbol) and left-turn
bike lane added north of the intersection
• December 31st, 2009
• Bike symbol added back

10. Scott/Oak Bike Box: Data Collection
• December 2009 (green but without bike symbol)
• 4 hours observing the evening peak
• February 2010 (green with bike symbol)
• 3 hours observing the evening peak
• Observations
• Vehicles – total stopped, stopping location (in bike
box, behind advanced stop bar)
• Bikes – total stopped, stopping location (bike box,
crosswalk, bike lane)

11. Scott/Oak Bike Box: Findings
Green “Bike Box” Green Bike Box w/
w/o Bike Symbol Bike Symbol
(December ‘09) (February ‘10)
Vehicle 50% 38%
encroachment (n=116) (n=119)
Bike stop Bike box 55% 61%
location Crosswalk 30% 25%
Bike lane 15% 14%
(n=276) (n=350)
• Use of bike box improved with installation of bike
symbol
• Some cars still encroach in the bike box
• Some bikes still stopping in crosswalk

12. 14th Street Bike Box
• Facilitates bike left turns from a one-way street to an
intersecting bike route
• 14th Street
– 2 lane, one-way street with bike lane
– Cars make double left turn from 14th
• Folsom Street
– 4 lane, two-way street with bike lane

13. 14th/ Folsom Bike Box: Data Collection
• Timeline:
• December 2004 - bike lane installed
• March 2005 - bike box installed
• Observations:
• September 2010
• 4 hours in each peak period (~240 cycles per peak)
• Vehicles – total stopped, stopping location (in bike
box, behind advanced stop bar)
• Bikes – total stopped, stopping location (bike box,
crosswalk, bike lane)

14. 14th/Folsom Bike Box: Findings
• 65% of the stopped bikes were turning left
Bike Box w/ Bike
Symbol
(September ‘10)
Vehicle encroachment 49%
(n=450)
Bike stop location (left- Bike box 34%
turning bikes) Crosswalk 15%
Bike lane 15%
Vehicle lane + 36%
ped xing (n=185)

15. 14th/Folsom Bike Box: Findings
Other observations:
• Many cyclists take advantage of a ped head start
• Some cyclists simply merged with traffic
• Conflicts persisted with right-turning cars
Conclusions:
• Bike box helps position bicyclists properly for left turns
• Some cars still encroaching in the bike box
• Some bikes still encroaching in crosswalk
• Need more work to discourage right on red

16. Synthesis
14th Street 14th Street – Scott St – Scott St –
– Advanced Advanced Advanced Advanced
stop bar stop bar + stop bar + stop bar +
Bike green green + bike
symbol symbol
Vehicle 55% 49% 50% 38%
encroachment
• Vehicle compliance with advanced stop bar was highest
with green paint and the bike symbol

17. State Route 227 in San Luis Obispo

18. Existing Intersection

19. Proposed Bike Box

20. Community Feedback
• Overwhelming support from local bike
advocacy groups and City of San Luis Obispo
• Overwhelming support from other advocacy
groups across the state and nation
• Support from several other California cities
including Santa Rosa, Long Beach, San
Francisco

21. Issues
• High auto volume creates need for refuge
area for cyclists
• No standard on bike boxes in CA MUTCD
• Experimental bike boxes in several CA cities
has created a need to codify bike box
standards to lessen confusion for road users
• Can there be separate stop lines for different
road users (motorists, cyclists)?

22. Response from California Traffic
Control Devices Committee
• Request to experiment denied by CTCDC
– Intersection has “non-typical” design
configuration due to refuge island
– Should consider a different intersection for
experimentation
• Caltrans instructed to apply to FHWA first and
then return to the CTCDC

23. Next Steps in San Francisco
• Follow-up work to improve effectiveness of bike boxes
• Engineering modifications
• Enforcement of no right on red
• Education of drivers and cyclists
• Synthesize evaluation methodology
• Identify additional pilot locations
• Monitor performance under various operating
conditions
• Finalize design guidelines on the use of bike boxes
• Support efforts to adopt bike box standards in California

24. Questions?
Contact information:
Jessica Manzi
Project Development
SFMTA-Livable Streets
jessica.manzi@sfmta.com
(415)701-4548
Adam Fukushima, Bike Coordinator
Caltrans – District 5
(805) 549-3131
Adam.fukushima@dot.ca.gov