title: Driver reaction time to tactile and auditory rear-end collision warnings while talking on a cell phone.
abstract: 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.
  
  
  METHODS
  Sixteen participants in a driving simulator experienced three collision warning conditions (none, tactile, and auditory) in three conversation conditions (none, simple hands free, complex hands free). Driver RT was captured from warning onset to brake initiation (WON2B).
  
  
  RESULTS
  WON2B times for auditory warnings were significantly larger for simple conversations compared with no conversation (+148 ms), whereas there was no significant difference between these conditions for tactile warnings (+53 ms). For complex conversations, WON2B times for both tactile (+146 ms) and auditory warnings (+221 ms) were significantly larger than during no conversation. During complex conversations, tactile warnings produced significantly shorter WON2B times than no warning (-141 ms).
  
  
  CONCLUSIONS
  Tactile warnings are more effective than auditory warnings during both simple and complex conversations.
  
  
  CONCLUSIONS
  These results indicate that tactile rear-end collision warnings have the potential to offset some of the driving impairments caused by cell phone conversations.
authors.affiliation: Arizona State University, Mesa, Arizona, USA.
authors.forename: Rayka
authors.initials: R
authors.lastname: Mohebbi
authors.forename: Rob
authors.initials: R
authors.lastname: Gray
authors.forename: Hong Z
authors.initials: HZ
authors.lastname: Tan
mesh_terms: D000063:Accidents, Traffic / Q000517:prevention & control*; D000328:Adult; D001288:Attention; D001334:Automobile Driving; D040421:Cell Phone; D004868:Equipment Failure; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011930:Reaction Time; D055815:Young Adult