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.

Keywords: Built environment; Pedestrian signals; Pedestrian-motor vehicle collisions; Pedestrians; Peru; Traffic signals.

Figure 1. Pedestrian Signal Types

There are a variety of pedestrian signals in Lima, but can be classified into two groups: stationary and countdown. A) Stationary pedestrian signal; B) Countdown pedestrian signal with a moving figure. C) Another example of countdown pedestrian signal with a moving figure.

Figure 2. Road Geometry Definitions

The index crossing area was the area under study observation at an in intersection. A leg was an intersecting road at an intersection. A refuge was an area that provided a space for pedestrians to pause their crossing. A segment was a subdivision of the crossing area created by a refuge.

Figure 3. Flowchart of Pedestrian-Motor Vehicle Collisions at Intersections for Study Inclusion