Effects of early notifications on driver responses to lateral collision warnings

Despite the demonstrated effectiveness of advanced driver assistance systems, lateral collisions still occur because of incorrect and deferred responses of drivers to potential hazards attributed to approaching vehicles from the sides. In such a situation, this study introduces early notifications prior to lateral collision warnings, displayed in either a visual-only format or a visual-auditory format. These notifications inform drivers about the presence of approaching vehicles from behind in adjacent lanes, aiming to improve their performance after receiving lateral collision warnings. The improvement is measured by analyzing the differences in drivers' reaction times and exhibition of appropriate reactions when early notifications are present and absent. Additionally, the effects of confounding factors including display formats (visual-only versus visual-auditory), drivers' socio-demographics, and driving experience on drivers' reaction times and exhibition of appropriate reactions are considered in the binary logit and Tobit models. Furthermore, the effects of individual heterogeneity are accounted using the random parameters approach. Results indicate that there is significant heterogeneity in drivers' reaction time when early notifications is present, prior to lateral collision warnings. Even that drivers' reaction time may increase in some circumstances, their likelihood of exhibiting appropriate reactions increases. However, it is interesting to find that drivers' reaction time increases and their likelihood of exhibiting appropriate reactions decreases when early notifications are presented in a visual-auditory format, compared to a visual-only format.