title: Pedestrian signalization and the risk of pedestrian-motor vehicle collisions in Lima, Peru.
abstract: Safe walking environments are essential for protecting pedestrians and promoting physical activity. In Peru, pedestrians comprise over three-quarters of road fatality victims. Pedestrian signalization plays an important role managing pedestrian and vehicle traffic and may help improve pedestrian safety. We examined the relationship between pedestrian-motor vehicle collisions and the presence of visible traffic signals, pedestrian signals, and signal timing to determine whether these countermeasures improved pedestrian safety. A matched case-control design was used where the units of study were crossing locations. We randomly sampled 97 control-matched collisions (weighted N=1134) at intersections occurring from October, 2010 to January, 2011 in Lima. Each case-control pair was matched on proximity, street classification, and number of lanes. Sites were visited between February, 2011 and September, 2011. Each analysis accounted for sampling weight and matching and was adjusted for vehicle and pedestrian traffic flow, crossing width, and mean vehicle speed. Collisions were more common where a phased pedestrian signal (green or red-light signal) was present compared to no signalization (odds ratio [OR] 8.88, 95% Confidence Interval [CI] 1.32-59.6). A longer pedestrian-specific signal duration was associated with collision risk (OR 5.31, 95% CI 1.02-9.60 per 15-s interval). Collisions occurred more commonly in the presence of any signalization visible to pedestrians or pedestrian-specific signalization, though these associations were not statistically significant. Signalization efforts were not associated with lower risk for pedestrians; rather, they were associated with an increased risk of pedestrian-vehicle collisions.
authors.affiliation: Harborview Injury Prevention & Research Center, University of Washington, 325 Ninth Ave, Box 359960, Seattle, WA 98104-2499, USA; Department of Pediatrics, School of Medicine, University of Washington, 1959 NE Pacific St., Box 356320, Seattle, WA 98195-6320, USA; Department of Epidemiology, School of Public Health, University of Washington, 1959 NE Pacific St., Box 357236, Seattle, WA 98195-7236, USA. Electronic address: aquistbe@uw.edu.
authors.forename: D Alex
authors.initials: DA
authors.lastname: Quistberg
authors.affiliation: Harborview Injury Prevention & Research Center, University of Washington, 325 Ninth Ave, Box 359960, Seattle, WA 98104-2499, USA; Department of Epidemiology, School of Public Health, University of Washington, 1959 NE Pacific St., Box 357236, Seattle, WA 98195-7236, USA.
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Koepsell
authors.affiliation: Harborview Injury Prevention & Research Center, University of Washington, 325 Ninth Ave, Box 359960, Seattle, WA 98104-2499, USA; Department of Industrial and Systems Engineering, University of Washington, Box 352650, Seattle, WA 98195-2650, USA.
authors.forename: Linda Ng
authors.initials: LN
authors.lastname: Boyle
authors.affiliation: School of Medicine, Universidad Peruana Cayetano Heredia, Av. Honorio Delgado 430, Urb. Ingeniería, San Martin de Porres, Lima, Peru; CRONICAS Center of Excellence in Chronic Diseases, Universidad Peruana Cayetano Heredia, Av. Armendáriz 497, 2do Piso, Miraflores, Lima, Peru.
authors.forename: J Jaime
authors.initials: JJ
authors.lastname: Miranda
authors.affiliation: Harborview Injury Prevention & Research Center, University of Washington, 325 Ninth Ave, Box 359960, Seattle, WA 98104-2499, USA; Department of Pediatrics, School of Medicine, University of Washington, 1959 NE Pacific St., Box 356320, Seattle, WA 98195-6320, USA.
authors.forename: Brian D
authors.initials: BD
authors.lastname: Johnston
authors.affiliation: Harborview Injury Prevention & Research Center, University of Washington, 325 Ninth Ave, Box 359960, Seattle, WA 98104-2499, USA; Department of Pediatrics, School of Medicine, University of Washington, 1959 NE Pacific St., Box 356320, Seattle, WA 98195-6320, USA; Department of Epidemiology, School of Public Health, University of Washington, 1959 NE Pacific St., Box 357236, Seattle, WA 98195-7236, USA; Seattle Children's Hospital and Seattle Children's Research Institute, 4800 Sand Point Way NE, Seattle, WA 98105, USA.
authors.forename: Beth E
authors.initials: BE
authors.lastname: Ebel
mesh_terms: D000056:Accident Prevention / Q000379:methods*; D000063:Accidents, Traffic / Q000517:prevention & control* / Q000706:statistics & numerical data; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D002947:Cities; D004779:Environment Design; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010568:Peru; D018570:Risk Assessment; D012307:Risk Factors; D016138:Walking; D055815:Young Adult
keywords: Built environment; Pedestrian signals; Pedestrian-motor vehicle collisions; Pedestrians; Peru; Traffic signals