Crosswalk markings and the risk of pedestrian-motor vehicle collisions in older pedestrians.

CONTEXT Motor vehicles struck and killed 4739 pedestrians in the United States in the year 2000. Older pedestrians are at especially high risk. OBJECTIVE To determine whether crosswalk markings at urban intersections influence the risk of injury to older pedestrians. DESIGN Case-control study in which the units of study were crossing locations. SETTING Six cities in Washington and California, with case accrual from February 1995 through January 1999. PARTICIPANTS A total of 282 case sites were street-crossing locations at an intersection where a pedestrian aged 65 years or older had been struck by a motor vehicle while crossing the street; 564 control sites were other nearby crossings that were matched to case sites based on street classification. Trained observers recorded environmental characteristics, vehicular traffic flow and speed, and pedestrian use at each site on the same day of the week and time of day as when the case event had occurred. MAIN OUTCOME MEASURE Risk of pedestrian-motor vehicle collision involving an older pedestrian. RESULTS After adjusting for pedestrian flow, vehicle flow, crossing length, and signalization, risk of a pedestrian-motor vehicle collision was 2.1-fold greater (95% confidence interval, 1.1-4.0) at sites with a marked crosswalk. Almost all of the excess risk was due to 3.6-fold (95% confidence interval, 1.7-7.9) higher risk associated with marked crosswalks at sites with no traffic signal or stop sign. CONCLUSIONS Crosswalk markings appear associated with increased risk of pedestrian-motor vehicle collision to older pedestrians at sites where no signal or stop sign is present to halt traffic.