The role of working memory in supporting drivers' situation awareness for surrounding traffic

To link working memory to driver situational awareness (SA) for surrounding traffic.

Operating a motor vehicle is a complex activity that requires drivers to maintain a high level of SA. Working memory has been conceptually linked to SA; however, the roles of working memory subsystems in supporting driver SA is unclear.

Participants drove a simulated vehicle and monitored surrounding traffic while concurrently performing either visuospatial- or phonological-load tasks. Drivers' SA was indexed as the ability to recall the positions of the surrounding traffic relative to their own vehicle at the end of each trial.

In Experiment I, a visuospatial task interfered with drivers' ability to recall the positions of traffic located in front of their vehicle. In contrast, a phonological task interfered with drivers' ability to recall the positions of traffic located behind their vehicle. Experiment 2 confirmed and extended the findings of Experiment I with the use of different visuospatial- and phonological-load tasks.

Visuospatial and phonological codes play a role in supporting driver SA for traffic located in the forward view and the rear view, respectively.

Drivers' SA for surrounding vehicles is disrupted by concurrent performance on secondary tasks. The development and implementation of new in-cabin communication, navigation, and informational technologies needs to be done with the knowledge that components of drivers' working memory capacity may be exceeded, thereby compromising driving safety.