Multilevel models for evaluating the risk of pedestrian-motor vehicle collisions at intersections and mid-blocks.
Walking is a popular form of physical activity associated with clear health benefits. Promoting safe walking for pedestrians requires evaluating the risk of pedestrian-motor vehicle collisions at specific roadway locations in order to identify where road improvements and other interventions may be needed. The objective of this analysis was to estimate the risk of pedestrian collisions at intersections and mid-blocks in Seattle, WA. The study used 2007-2013 pedestrian-motor vehicle collision data from police reports and detailed characteristics of the microenvironment and macroenvironment at intersection and mid-block locations. The primary outcome was the number of pedestrian-motor vehicle collisions over time at each location (incident rate ratio [IRR] and 95% confidence interval [95% CI]). Multilevel mixed effects Poisson models accounted for correlation within and between locations and census blocks over time. Analysis accounted for pedestrian and vehicle activity (e.g., residential density and road classification). In the final multivariable model, intersections with 4 segments or 5 or more segments had higher pedestrian collision rates compared to mid-blocks. Non-residential roads had significantly higher rates than residential roads, with principal arterials having the highest collision rate. The pedestrian collision rate was higher by 9% per 10 feet of street width. Locations with traffic signals had twice the collision rate of locations without a signal and those with marked crosswalks also had a higher rate. Locations with a marked crosswalk also had higher risk of collision. Locations with a one-way road or those with signs encouraging motorists to cede the right-of-way to pedestrians had fewer pedestrian collisions. Collision rates were higher in locations that encourage greater pedestrian activity (more bus use, more fast food restaurants, higher employment, residential, and population densities). Locations with higher intersection density had a lower rate of collisions as did those in areas with higher residential property values. The novel spatiotemporal approach used that integrates road/crossing characteristics with surrounding neighborhood characteristics should help city agencies better identify high-risk locations for further study and analysis. Improving roads and making them safer for pedestrians achieves the public health goals of reducing pedestrian collisions and promoting physical activity.
Harborview Injury Prevention & Research Center, University of Washington, 325 Ninth Avenue, Box 359960, Seattle, WA 98104-2499, USA; Department of Pediatrics, University of Washington, 1959 NE Pacific Street, Box 356320, Seattle, WA 98195-6320, USA. Electronic address: aquistbe@uw.edu.
D Alex
DA
Quistberg
Urban Form Lab, University of Washington, Box 354802,1107 NE 45th Street, Suite 535, Seattle, WA 98105-4631, USA; Department of Urban Design and Planning, University of Washington, Box 355740, 3950 University Way NE, Seattle, WA 98195-5740, USA.
Eric J
EJ
Howard
Harborview Injury Prevention & Research Center, University of Washington, 325 Ninth Avenue, Box 359960, Seattle, WA 98104-2499, USA; Department of Pediatrics, University of Washington, 1959 NE Pacific Street, Box 356320, Seattle, WA 98195-6320, USA; Department of Epidemiology, University of Washington, 1959 NE Pacific Street, Box 357236, Seattle, WA 98195-7236, USA; Seattle Children's Research Institute, Seattle Children's Hospital, 4800 Sand Point Way NE, Seattle, WA 98105, USA.
Beth E
BE
Ebel
Urban Form Lab, University of Washington, Box 354802,1107 NE 45th Street, Suite 535, Seattle, WA 98105-4631, USA; Department of Urban Design and Planning, University of Washington, Box 355740, 3950 University Way NE, Seattle, WA 98195-5740, USA.
Anne V
AV
Moudon
Department of Pediatrics, University of Washington, 1959 NE Pacific Street, Box 356320, Seattle, WA 98195-6320, USA; Seattle Children's Research Institute, Seattle Children's Hospital, 4800 Sand Point Way NE, Seattle, WA 98105, USA.
Brian E
BE
Saelens
Urban Form Lab, University of Washington, Box 354802,1107 NE 45th Street, Suite 535, Seattle, WA 98105-4631, USA; Department of Urban Design and Planning, University of Washington, Box 355740, 3950 University Way NE, Seattle, WA 98195-5740, USA.
Philip M
PM
Hurvitz
Seattle Department of Transportation, Seattle Municipal Tower, P.O. Box 34996, 700 Fifth Avenue, Suite 3800, Seattle, WA 98124-4996, USA.
James E
JE
Curtin
Harborview Injury Prevention & Research Center, University of Washington, 325 Ninth Avenue, Box 359960, Seattle, WA 98104-2499, USA; Department of Pediatrics, University of Washington, 1959 NE Pacific Street, Box 356320, Seattle, WA 98195-6320, USA; Department of Epidemiology, University of Washington, 1959 NE Pacific Street, Box 357236, Seattle, WA 98195-7236, USA; Seattle Children's Research Institute, Seattle Children's Hospital, 4800 Sand Point Way NE, Seattle, WA 98105, USA.
Frederick P
FP
Rivara
D000063:Accidents, Traffic / Q000706:statistics & numerical data*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D004779:Environment Design; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D055361:Multilevel Analysis; D000069636:Pedestrians / Q000706:statistics & numerical data*; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D012449:Safety / Q000706:statistics & numerical data*; D014861:Washington; D055815:Young Adult
Built environment; Collision risk; Multilevel model; Pedestrians