Principle Other Vehicle Warning

The only possibility for a driver to avoid a collision may sometimes be to issue a warning to another driver. Connecting the horn and the headlight to an already existing sensor system could be a cost effective solution. This report covers the implementation and evaluation of such an automated warning system in a driving simulator at VTI. In this test 24 drivers with normal hearing and 24 with moderate hearing loss experienced five critical events in which four different warning signals were evaluated; sound, light, and a combination of sound and light, and no warning (as reference). A visual distraction task was used to distract the drivers and create critical situations. The results were consistent. A combined sound and light warning significantly increased cautious driving behaviour and also lead to the highest perceived criticality of the situations. With the combined warning the driver’s attention was effectively drawn from the visual distraction task. Drivers were generally positive towards the warning system, and most positive towards the combined warning presenting light and sound signals. Drivers were able to distinguish between warnings (at critical events) and greetings (at non-critical events) suggesting that the tested additional use of horn and headlight would not affect reactions to non-critical warnings or greetings. Hearing loss was associated with worse performance on the visual distraction task and less perceived realism of the driving simulator. But it was not associated with effects on any driving behaviour measures or of warning modalities. This result suggests that the evaluated system should work also for drivers with moderate hearing loss.