Field investigation of driver response to in-vehicle safety warning information

Abstract

The effectiveness of the advance warning in-vehicle system was evaluated by reviewing drivers' abilities to respond appropriately to unsafe conditions in real-time driving scenarios. A probe vehicle was used to collect individual vehicle speed as well as its speed change rates. The probe vehicle was also equipped with a Global Positioning System (GPS) that generated the individual vehicle trajectory. The driver's response was evaluated under two different types of warning system, emergency warning and general warning, using various combinations of modalities that include text, digital tones, voice messages, and graphics. Study results show that for emergency alert, warning information transmitted by integrating' voice, graphic and text' or 'repeated computer tone and text' was most effective. In the case of a general warning alert, 'repeated computer tone, voice, graphic, and text' combination was found to be most effective. This study provides an overall guideline for designing an effective in-vehicle warning system.