Evaluation of Bike Boxes at Signalized Intersections [Presentation]

Transcription

1 Portland State University PDXScholar Urban Studies and Planning Faculty Publications and Presentations Nohad A. Toulan School of Urban Studies and Planning Evaluation of Bike Boxes at Signalized Intersections [Presentation] Jennifer Dill Portland State University, Christopher M. Monsere Portland State University, Let us know how access to this document benefits you. Follow this and additional works at: Part of the Urban Studies and Planning Commons Citation Details Dill, Jennifer and Monsere, Christopher M., "Evaluation of Bike Boxes at Signalized Intersections [Presentation]" (2010). Urban Studies and Planning Faculty Publications and Presentations This Presentation is brought to you for free and open access. It has been accepted for inclusion in Urban Studies and Planning Faculty Publications and Presentations by an authorized administrator of PDXScholar. For more information, please contact

2 An Evaluation of Bike Boxes at Signalized Intersections in Portland, OR Christopher Monsere, Ph.D., P.E. Civil & Environmental Engineering Jennifer Dill, Ph.D. Urban Studies & Planning Nathan McNeil Center for Transportation Studies

3 Bike Boxes in Portland 9 - Green Bike Boxes 3 - Uncolored Bike Boxes

4 Typical Design

5 Our Research Questions Do road users (motorists and cyclists) understand the markings? Do road users behave as intended? Are the markings improving safety? Does color (green vs. no color) matter?

6 Methods: Video Data Pre & Post video 10 bike box (7 green, 3 uncolored) 2 control 2 peak and 1 off-peak hours analyzed per location +56 more hours for conflict analysis Before video: Jan to March 2008 After video: April to June 2009

7 Methods: Surveys Intercept survey of bicyclists 5 bike box intersections 47% response rate (468 of 997) On-line survey of motorists 24% response rate (717 of 3,020)

8 Do Users Understand the Markings?

9 Motorist Survey If you approached an intersection with a red light where should you stop your car? 9% in box <1% either 1% don t know 89% 2% in box 1% either 3% don t know 94%

10 Do Users Behave as Intended?

11 Motorist Encroachment in the Bike Box % of motor vehicles arriving on red signal encroaching in the bike box All Encroachments 23% 28% Minor Moderate 5% 3% 13% 12% Color No Color Major 10% 8%

12 Comparing Encroachments of Motor Vehicles in Bike Boxes (Post) vs. Crosswalks (Pre) % of motor vehicles arriving on red signal encroaching All Intersections p= % 27% Bike Box Crosswalk Color p= % 28% No Color p= % 23%

13 Location of Stopped Cyclist in Box B (in box, bike lane area) A (in box, in front of MV lane) C (bike lane behind box) D (other) No other bike present A (in box, in front of MV lane) C (bike lane behind box) Bike in Location B 73% of cyclists stop ahead of motor vehicle (A or B), though only 9% in front (area A)

14 Are the markings improving safety? Video data Motor vehicle encroachment into crosswalk Cyclist encroachment into crosswalk Motor vehicle encroachment into bike lane Yielding behavior Conflicts Survey data Perceptions of safety (motorists and cyclists)

15 Motor Vehicle Encroachment in Crosswalk % of motor vehicles arriving on red signal encroaching in the crosswalk Control p= % 13% Before After No Color p= % 19% Color p= % 25%

16 Cyclist Encroachment in Crosswalk % of cyclists arriving on red signal encroaching in the crosswalk Control p= % 23% Before After No Color p= % 23% Color p= % 41%

17 Motorist Encroachment in Bike Lane 90% % of right-turning motor vehicles encroaching in the bike lane 80% 70% 60% Before After * sig. p < % 40% 30% 20% 10% 0% Color * No Color Control * Color * No Color Control Color * No Color * Control * Prior to Arriving at Intersection While Stopping at Red Signal While Making a Right Turn

18 Bicycles Rt. Turning Cars Car to Cyclist Car Fails to Yield Yielding Behavior Counts Yielding Events NE Weidler & NE 7th After Before After Before SE Hawthorne & SE 7th NW Broadway & NW Hoyt After After Before Before Number of vehicles observed Number of Events

19 Number of Conflicts Conflicts between motor vehicles and bicycles Before After % bicycle volumes +15% right turning cars Overall, decrease from 29 to 20 (-31%) conflicts NW Bway & Hoyt NW Everett & 16th SE 11th & Hawthorne SE 7th & Hawthorne SW 3rd & Madison SW Bway & Taylor No conflicts before or after at three bike box intersections and both control intersections. W Burnside & 14th Ave

20 Motorist Survey Do you think the bike box has made driving safer or more dangerous at the intersections? All motorists Motorists who are not cyclists A lot safer 16% 13% A little safer 36% 29% No difference 18% 17% A little more dangerous 9% 11% A lot more dangerous 3% 4% Don t know 18% 27% n %

21 Motorist Survey Of the motorists who are not cyclists 41% think the bike boxes make driving less convenient at the intersections 33% feel more comfortable driving through the intersections (16% less comfortable) 52% think the bike boxes make drivers more aware of bicyclists generally 38% think the City should install more boxes 11% think the City should remove some or all

22 Bicyclist Survey Do you think the bike box has made the intersection safer for you as a cyclist? A little more dangerous 2% I don't know 8% No difference 13% A lot safer 20% A little safer 57%

23 Does Color Matter?

24 Video Observation Two of the three non-color locations have far fewer cyclists and motor vehicles Higher level of total motor vehicle encroachment in colored boxes Also had higher level of encroachment before boxes Higher rate of cyclists using box as intended in colored boxes

25 Motorist Survey As a driver, do you think one of the pavement marking designs is better than the other? 6% 89%

26 Conclusions Findings that support bike boxes Compliance and understanding is high Pedestrians are benefitting from reduced crosswalk encroachment Conflicts fell Yielding behavior increased Improved perceptions of safety Unclear findings Increase in bike lane encroachment Benefits of color

27 Phase 2 Longer video collection at 14 locations. Includes view of signal indications to look at conflicts and arrival patterns on green.

28 Acknowledgements City of Portland Rob Burchfield Tom Jensen Matthew Machado Roger Geller Student Research Assistants Nathan McNeil Bob Kellett Will Farley OTREC

29 Questions? Christopher Monsere Find the full report: Accident Analysis & Prevention article online