Driver eye glance behavior during car following: timing matters

Using data from a naturalistic driving study in which participants drove research vehicles equipped with an integrated crash warning system, five video cameras (including a face camera video), and a data acquisition system, researchers examined driver eye glance behavior during car following and prior to valid, forward crash warnings (FCWs). Range, range rate, time headway, and speed were obtained at the time of each glance away from the forward scene. For car following, across all drivers and ranges, the results showed that when drivers did look away from the road, the range rate was near zero (i.e. no closing). Regardless of age group, on average, drivers glanced away from the forward scene at time headways in excess of two seconds. Provided that the lead vehicle does not brake unexpectedly, these results suggest that drivers are making prudent decisions about when to look away from the road. The results from the analysis of glance behavior prior to FCWs showed that on average drivers looked away from the road at closer ranges and while closing as compared to when drivers were car following.