Knowledge of state-recommended following-distance rules

Rear-end accidents are often attributed to the following vehicle not allowing sufficient headway to react in the event of a sudden change in velocity by the lead vehicle. Accordingly, most U.S. state DMVs offer seconds-based guidelines for safe following distances such as a ‘three-second rule’. However, studies have demonstrated that headways shorter than those recommendations are common. While numerous explanations can account for these observations, fundamentally, drivers must be aware of following distance recommendations in order to follow them. Here, we tested drivers’ knowledge of the following-distance rule (FDR). Results demonstrated that only 55.2% of survey respondents knew their state had an FDR, only 13.4% knew that it was based off of a seconds method, and only 2.4% accurately identified their state’s specific FDR. Factors associated with FDR knowledge included number of years of licensure and self-reported knowledge of driving rules.