ABSTRACT
To control a vehicle in the dynamic roadway environment, a varying portion of the driver’s attention must be allocated to the driving task. Under many circumstances, the fl ow of traffi c may stabilize or disperse, making the following few seconds seem quite predictable and freeing the driver’s attention to intermittently engage in nondriving activities for a few moments. Many tasks that are unrelated to driving may compete for the driver’s attentional resources, such as talking with passengers, conversing on a cellular phone, or interacting with cellular phones or other nomadic devices. Even different driving-related tasks may compete with each other such that, while checking the blind spot, the driver is unable to simultaneously survey the forward road scene for potential threats. Drivers’ expectations typically guide attention to potential threats in an effi cient manner. Although many miles may pass without event, inevitably a situation will suddenly emerge that violates the driver’s expectations. When such an unexpected and sudden situation develops, a driver may fail to devote suffi cient attention to the roadway to support a timely and appropriate response. Collision warning systems can support the driver in these situations
by directing the driver’s attention to the unexpected or unnoticed situation on the roadway.
