Pedestrian environment and behavior in Karachi, Pakistan.

Pedestrian road traffic accidents (RTAs) are responsible for a substantial number of injuries and deaths in Karachi. To better understand the situations facing pedestrians we selected ten of Karachi's highest risk locations for pedestrian RTAs and observed 250 pedestrians for each of three activities--crossing the street, walking on the street, and walking on the sidewalk. We also observed the extent and effect of street and sidewalk encroachments. A total of 35% of the pedestrians crossing the street caused traffic to swerve to avoid them. Pedestrians crossing one lane at a time were 2.9 times more likely to cause the traffic to swerve than pedestrians who crossed the whole street at once (53 vs. 18%, RR = 2.9, 95% CI = 1.9-4.3). Pedestrians crossing in a group were 1.8 times more likely to cause traffic to swerve compared to those crossing singly (49 vs. 28%, RR = 1.8, 95% CI = 1.3-2.5, P = 0.001). A total of 36% ran while crossing and were 1.8 times more likely to cause traffic to swerve than those who walked (48 vs. 27%, RR = 1.8, 95% CI = 1.3-2.5). An average of 77% of the sidewalk width was blocked by encroachments which forced pedestrians to step on the road resulting in vehicles swerving. An average 33% of the street width was blocked by illegally parked vehicles. Pedestrians in Karachi indulge in risky behaviors. Encroachments on streets and sidewalks compound the problem. Piloting efforts to modify pedestrian behavior and the environment they negotiate should be considered to reduce pedestrian deaths.