Population-based case-control study of the effect of sun glare on pedestrian fatalities in Taiwan

Objectives Sun glare is a serious driving hazard and increases crash risks. Relatively few studies have examined the effects of sun glare on pedestrian fatalities, given that a crash has occurred. The primary objective of this study was to investigate the effect of sun glare on pedestrian fatalities. Design A population-based case-control study. Setting Taiwan. Participants Using the Taiwan National Traffic Crash Data and sunrise and sunset data from the National Oceanic and Atmospheric Administration for the period 2003 to 2016, 100 411 pedestrians involved in crashes were identified. Of these crashes, 13 355 and 87 056 were glare-related (case) and non-glare-related (control) crashes, respectively. Methods To account for unobserved heterogeneity, mixed logit models were estimated to identify the determinants of pedestrian fatalities. Main outcome measures Pedestrian fatalities. Results Pedestrians involved in glare-related crashes were more likely to be fatally injured than those in non-glare-related crashes (β=0.527; t=3.21). Other contributory factors to fatal injuries among pedestrians were older pedestrians (β=0.553; t=2.33), male drivers (β=0.324; t=2.33), older drivers (β=0.218; t=2.14), intoxicated motorists (β=0.606; t=2.85), rural roadways (β=0.985; t=3.92), overtaking manoeuvres (β=0.472; t=3.58), heavy vehicle crash partners (β=0.248; t=2.78) and sunset hours (β=0.274; t=3.08). Walking against traffic appeared beneficial for decreasing injury severity (β=-0.304; t=-2.76). Conclusions Sun glare is associated with pedestrian fatalities. Older pedestrians, male drivers, older drivers and intoxicated motorists are prevalent determinants of pedestrian fatalities in glare-related crashes.