Background To reduce road trauma we must better understand the factors contributing to crashes. In Queensland, Australia, rear end crashes are the 3rd leading crash type, with mild to serious injuries a likely outcome and whiplash a common injury occurrence. Road design, traffic congestion, and weather/road conditions have been implicated in rear end crashes. Human factors also play a key role, with the act of ‘following too closely’ being a major issue. Queensland legislation requires motorists to maintain a safe following distance between their vehicle and the one in front, although no specific information about this distance is prescribed by law for cars.

Methods To better understand perceptions of safe following distance, 495 licensed Queensland drivers (42% male; mean age 46.2 yrs; range 16–81 yrs) completed an online questionnaire.

Results Overall, there was wide variation in descriptions of safe following distance including time between vehicles (2 seconds = 21%; 3 seconds = 11%), distance between vehicles (metres = 11%; car lengths = 32%); and combinations of time and distance (1%). No one reported having received an infringement for not keeping a safe following distance, although 29% reported being involved in a crash where their vehicle hit the one in front. The majority (86%) reported that it was somewhat-extremely unlikely they would be caught by police if following too closely, indicating a perceived lack of enforcement for this offence. Reasons for this included perceptions of difficulty for police to enforce this offence (5%), not having heard of anyone being caught for this offence (17%), and other police priorities (30%).

Conclusions This study is part of a larger research project that aims to improve knowledge about driving conditions, patterns and locations, and driver behaviours that lead to driving at unsafe headways (i.e. following too closely). Recommendations for use of these findings to inform driver education and awareness campaigns are discussed.