This simulator-based study examined the use of conventional auditory warnings (tonal, non-verbal sounds) and auditory icons (representational, non-verbal sounds), alone and in combination with a dash-mounted visual display to warn commercial motor vehicle operators of impending front-to-rear and side collision situations. Driver performance was measured in the simulated driving task via brake response time in the front-to-rear collision scenarios and via a count of accident occurrence in the side collision scenarios. For both front-to-rear and side collision scenarios, auditory icons elicited significantly improved driver performance over conventional auditory warnings. Driver performance improved when collision warning information was presented through multiple modalities.
