Background Research has suggested that sun glare poses serious driving hazards and increases accident risks. Relatively few studies, however, have been conducted to examine the effects of sun glare on motorcyclist injury severity, given that an accident has occurred.

Objectives This study attempts to investigate whether sun glare results in an increased injury severity sustained by motorcyclists. Method Using UK Stats19 accident data (1990–2010), the investigation was conducted by comparing and contrasting crashes that are possibly affected by sun glare (face-sun) with those not affected by sun glare (back-to-sun). A pooled binary logit model was estimated to identify whether face-sun crashes were more injurious than back-to-sun crashes, while controlling for other variables. One additional binary logit model by face-sun crashes was then estimated to identify the contributory factors to KSIs (killed or seriously injured).

Results A total of 5 30 291 motorcycle crashes were extracted from the Stats19 for the period 1990–2010. It was found that drivers in face-sun crashes were 1.11 times more likely to sustain KSI (AOR=1.11; CI: 1.082–1.134), compared to those in back-to-sun crashes. The face-sun logistic model reveals several important determinants of KSI: for instance, male riders, elderly riders, urban roadways, and those riding heavier motorcycles.

Conclusions We conclude that sun glare is associated with an increased injury severity sustained by motorcyclists. To reduce injury severity, intervention points are discussed finally.