External-To-Vehicle Distractions: Dangerous Because Deceiving

Distractions outside the vehicle are a growing cause of concern. Effects of external distractions are not just limited to younger novice drivers, as is the case with in-vehicle distractions. Experienced drivers\u27 ability to maintain their attention on the forward roadway and their ability to anticipate hazards is also compromised in the presence of external distractions. This dissertation seeks to both understand the extent to which external-to-vehicle distractions affect driver safety and study the potential remedies for this problem. Driver behaviors, specifically the ability to anticipate and respond to hazards in the presence of external-to-vehicle distractions, were evaluated for different age groups in a driving simulator. Drivers\u27 performance was evaluated on three categories of hazard anticipation scenarios; (a) top-down explicitly cued scenarios (drivers were cued before they encountered the external-to-vehicle task), (b) top-down implicitly cued scenarios (drivers were cued before they encountered the external-to-vehicle task) and (c) bottom-up cued scenarios (drivers were cued after they encountered the external-to-vehicle task). Eye movement information and vehicle parameters were collected and analyzed. Drivers of all age groups were significantly affected by the presence of external-to-vehicle distractions regardless of the type of cue: drivers took long glances at the external-to-vehicle task, did not scan the appropriate locations for risk relevant elements, and responded significantly slower to hazards in the presence of external-to-vehicle distractions (Experiments 1 and 2). Training was considered as an intervention that could mitigate the effects of external distractions. As a start, the effect of a training program (FOCAL) that reduced the duration of in-vehicle glances on the duration of external-to-vehicle glances was evaluated in a simulator. The training was not effective in reducing the long duration of glances at the external task (Experiment 3). This finding lead to the development of a PC-based attention maintenance training program, FOCAL-Ex, that specifically addressed the issue of external-to-vehicle distractions. The evaluation was done on a PC. The percentage of external-to-vehicle tasks in which trained drivers took especially long glances was significantly less than this percentage for placebo trained drivers (Experiment 4)