Cyclist exposure to the risk of car door collisions in mixed function activity centers: A study in Melbourne, Australia.

OBJECTIVE: The objective of this study is to describe key risks related to dooring collisions on roads in mixed function activity centers by examining video footage recorded onboard the bicycles of cyclists riding through this road environment. The study aims to enhance our understanding of the risk associated with cyclist door collisions on these roads and to provide a focus for future studies that aim to identify measures that enhance cyclist safety. METHOD: The study measured 4 key risk exposures (per hour and kilometer), namely, on-street parked cars and 3 conditions associated with parked cars being accessed or egressed: door opened (a) after the cyclist passes (give-way event); (b) in the path of the cyclist without collision (obstruction event); and (c) in the path of the cyclist with collision (collision event). Exposure to the risk factors was measured using video footage recorded onboard the bicycles of adult cyclists (n = 25) as they rode through this road environment. The average speed of cyclists was also estimated from these video data and related to the measures of exposure. RESULTS: The cycling experiences of the participants were observed over 3 h 58 min and 84.0 km. On average, the sample was exposed to 1,166 parked car events per hour (55 per kilometer), 6.9 give-way events per hour (0.3 per kilometer), 2.3 obstruction events per hour (0.1 per kilometer), and no collision events. There were 9 instances of obstruction events. In most cases, the cyclist was clearly visible (n = 7; 77.8%) and modified his or her position to avoid the door (n = 8; 88.9%). Moreover, the door was opened by the driver in nearly all cases (n = 8; 88.9%), primarily to exit the vehicle (n = 4; 44.4%) or enter the vehicle (n = 3; 33.3%). The average speed of cyclists was 22.7 km/h (SD = 4.1 km/h), and average speed tended to reduce as exposure to parked car events increased. CONCLUSION: Cyclists seldom interact with a vehicle occupant accessing or egressing a parked car, yet a concerning proportion of these interactions involve the occupant opening the door in the path of the cyclist, rather than waiting for the cyclist to pass. This suggests that there is still considerable need to identify measures that increase the likelihood that a vehicle occupant will look for cyclists before opening the car door, particularly in road environments where longer-term solutions such as physical separation are not readily achieved.

Geospatial analysis of cyclist injury trends: an investigation in Melbourne, Australia.

OBJECTIVE: This study applied geospatial analysis to explore spatial trends in cycling-related injury in Melbourne, Australia, in order to identify an area where injury density was reducing against expectation. The crash characteristics and cycling environment of the identified area were examined to better understand factors related to cycling safety. METHOD: Two methods were used to examine spatial trends in cycling-related injury. Firstly, cycling injury density was calculated using a kernel density estimation method for the years 2000 to 2011. This was used to examine patterns in injury density across Melbourne over an extended time period. Secondly, absolute change in injury density was calculated between 2005 and 2011. From this, a geographical area presenting a reduced injury density was selected for a case study, and crash characteristics of the area were obtained for the observational period. This led to discussion on which changes to the cycling environment, if any, may be associated with the reduced injury rate. RESULTS: Injury density in Melbourne had been progressively increasing between 2000 and 2011, with a nearly 3-fold increase in the peak injury density over that period. Decreases were observed in some locations between 2005 and 2011, and a geographical area to the southeast of Melbourne experienced a more significant decrease than others. This appeared to be associated with a combination of behavior and road infrastructure change, although a lack of data to verify change in cycling exposure prevented more definitive associations from being established. CONCLUSION: The apparent positive response of the injury rate to behavior and road infrastructure interventions is promising, yet the injury rate is unlikely to achieve the government's road safety target of 30% reduction in serious injuries by 2022. Moreover, the number of injuries sustained at the most common crash location appears to be increasing. Further research is necessary to discern which specific features of the urban road infrastructure have an effect on the risk of injury to a cyclist and which combination of features is consistent with a safe cycling environment.