Impacts of Coordinating the Colors of Flashing Warning Lights and Vehicle Markings on Driver Perception

Flashing lights on emergency and maintenance vehicles should be critical components to alerting, informing and managing drivers as they navigate around work zones, vehicle accidents and other roadway emergency incident scenes. These vehicles often also use distinctive colors and markings to identify the type of vehicle and potentially provide drivers with information about the nature of the incident they are approaching. In order to begin to understand how these elements (flashing lights and vehicle/marking colors) contribute to perception, a study was carried out in which participants viewed pairs of roadway scenes using scale model vehicles and lights adjusted to produce similar apparent intensities as full-scale lighting systems. In some cases the colors of the flashing lights were coordinated with those of the vehicle and its reflective markings, and in other cases the colors were not coordinated. Participants reported which scenes appeared to be fire emergencies, as opposed to a non-emergency situation such as a roadway work zone. In addition to differences between different amounts of coordination between the color of the lights and the vehicles and markings, there were individual differences among the participants. The results can guide future research and can help in developing guidelines for the use of flashing light and vehicle marking colors to reinforce driver perception and awareness.