Background: This study was designed to examine the characteristics of pedestrian and bicyclist collisions with motor vehicles within New York City's high-density hub. The primary objectives were to map crash locations and to identify hot spots within these injury clusters. The secondary objective was to quantify differences in injury severity based on road type and user behaviors.
Methods: Between December 2008 and June 2011, data were prospectively collected from pedestrians and bicyclists struck by motor vehicles and brought to Bellevue Hospital, a Level 1 trauma center in New York City. Behaviors by cohort (i.e., crossing patterns for pedestrians, riding patterns for bicyclists), Injury Severity Score (ISS), and collision locations were extracted from the database. Analyses of mean ISS were performed using a Student's t test with a p < 0.05 considered significant. Geomaps were created to identify clusters or "hot spots," where higher volumes of crashes occurred over time. Spatial analysis was performed to demonstrate whether these were random events.
Results: A total of 1,457 patients (1,075 pedestrians and 382 bicyclists) were enrolled. Collision locations were known for 97.5%. Of the injured pedestrians, those crossing avenues (n = 277) had higher ISSs than those crossing streets (n = 522) (p = 0.01) and were more likely to die (p = 0.002). Pedestrians crossing midblock (n = 185) had higher mean ISSs than those crossing with the signal in the crosswalk (n = 320) (8.12 vs. 5.01, p < 0.001). Based on density mapping, hot spots of pedestrian collisions were detected in midtown Manhattan, while hot spots for bicyclists were detected at bridge and tunnel portals. Spatial analysis indicates that these are not random events (p < 0.05).
Conclusion: Pedestrians injured on avenues sustained more serious injuries than those injured on narrower streets. A better understanding of collision locations and features may allow for tailored injury prevention strategies. Trauma centers serve an important role in public health surveillance within their local communities.
Level of evidence: Epidemiologic study, level III.