Introduction:
Cycling is nowadays a crucial recreational activity and the most common transportation mode in the world. Numerous risk factors, such as road conditions, poor visibility, unlit conditions, and other geometric factors, contribute to bicycle crashes. While a vast majority of past studies focused on bicycle crashes that occurred at junctions, relatively little research has examined segment crashes.

Objectives This study aims to examine the risk factor for three common crash types on segments: overtaking, rear-end, and door crashes.

Methods:
By analysing British Stats19 accident data (1991-2020), our study evaluated bicycle overtaking, rear-end, and door crashes on segments. Independent variables of interest include age and sex of cyclist and crash partner, lighting condition, speed limit, crash partner’s vehicle type, crash day, and crash time. Multivariate logistic regression models were employed to estimate adjusted odds ratios (AORs) between potential risk factors. We further investigate joint effects of the variables with statistical significance. 4. Results A total of 127,637 bicycle segment crashes were analyzed, of which 18,350 (14.4%) were overtaking crashes, 44,962 (35.2%) were rear-end crush, and 6,363 (5.0%) were door crush. In overtaking crashes, bus/heavy good vehicles as crash partner was found to be a contributory factor (AORs = 2.87; 95% CI = 2.47 -- 3.23). Other risk factors include elderly crash partners (AORs = 2.01; 95% CI = 1.94 -- 2.09) and rural areas with speed limit ≥ 40mph (AORs =2.34; 95% CI = 2.16 -- 2.32). For rear-end crashes, darkness and unlit conditions (AORs = 1.49; 95% CI = 1.40 -- 1.57) and rural areas (AORs = 1.32; 95% CI = 1.28 -- 1.35) increase crash risks. As for door crashes, urban areas with speed limits up to 30 mph (AORs = 16.19; 95% CI = 13.51 -- 19.38) and taxi as crash partner (AORs = 2.69; 95% CI =2.31 --3.15) were risk factors. Several joint effects were identified to be significant, including rural area and elderly crash partner (AORs = 2.93; 95% CI = 2.79 -- 3.08) in overtaking crashes and darkness and rural area (AORs = 2.15; 95% CI = 2.01 -- 2.31) for rear-end crashes.

Conclusions:
Crucial risk factors include bus/heavy good vehicles, elderly drivers of crash partner, and rural areas for overtaking crashes; darkness with unlit conditions and rural areas for rear-end crashes; urban areas and taxi as crash partner for door crashes

Keywords: Cyclists

Other info: Graduate Institute of Injury Prevention and Control of Taipei Medical University - ROC, Taipei