Driver reaction time to tactile and auditory rear-end collision warnings while talking on a cell phone.

Objective: This study examined the effectiveness of rear-end collision warnings presented in different sensory modalities while drivers were engaged in cell phone conversations in a driving simulator.

Background: Tactile and auditory collision warnings have been shown to improve braking response time (RT) in rear-end collision situations. However, it is not clear how effective these warnings are when the driver is engaged in attentionally demanding secondary tasks, such as talking on a cell phone.