title: Effects of single versus multiple warnings on driver performance.
abstract: OBJECTIVE
  To explore how a single master alarm system affects drivers' responses when compared with multiple, distinct warnings.
  
  
  BACKGROUND
  Advanced driver warning systems are intended to improve safety, yet inappropriate integration may increase the complexity of driving, especially in high workload situations. This study investigated the effects of auditory alarm scheme, reliability, and collision event type on driver performance.
  
  
  METHODS
  Using a 2 x 2 x 4 mixed factorial design, we investigated the impact of two alarm schemes (master vs. individual) and two levels of alarm reliability (high and low) on distracted drivers' performance across four collision event types (frontal collision warnings, left and right lane departure warnings, and warnings for a fast-approaching following vehicle).
  
  
  RESULTS
  Participants' reaction times and accuracy rates were significantly affected by the type of collision event and alarm reliability. The use of individual alarms, rather than a single master alarm, did not significantly affect driving performance in terms of reaction time or response accuracy.
  
  
  CONCLUSIONS
  Even though a master alarm is a relatively uninformative warning, it produced statistically no different reaction times or accuracy results when compared with information-rich auditory icons, some of which were spatially located. In addition, unreliable alarms negatively impacted driver performance, regardless of event type or alarm scheme.
  
  
  CONCLUSIONS
  These results have important implications for the development and implementation of multiple driver warning systems.
authors: Aeronautics and Astronautics Department, Massachusetts Institute of Technology, Cambridge, MA 02139-4307, USA. missyc@mit.edu
authors: M L
authors: ML
authors: Cummings
authors: Ryan M
authors: RM
authors: Kilgore
authors: Enlie
authors: E
authors: Wang
authors: Louis
authors: L
authors: Tijerina
authors: Dev S
authors: DS
authors: Kochhar
mesh_terms: D000063:Accidents, Traffic / Q000517:prevention & control; D000328:Adult; D001288:Attention; D001334:Automobile Driving / Q000523:psychology*; D006804:Ergonomics / Q000295:instrumentation*; D005260:Female; D006801:Humans; D008297:Male; D011482:Protective Devices; D013647:Task Performance and Analysis; D014481:United States