

The blue flashing lights were always perceived as brighter and as more glaring than the red flashing lights at the same intensity. Participants identified the location of the police officer figure, if any, as quickly as possible. In some trials, no police officer figure was present. In some trials, white LED sources were energized, providing low-level illumination on both sides of the vehicle, near the possible locations of the police officer figure. Participants were asked to view the scale model police vehicle and identify whether a police officer figure was standing beside the vehicle. Lights varied in intensity and optical power (intensity × duration). In the present study, participants viewed red and blue flashing lights on a scale model police vehicle, conforming to present recommended practices for emergency lights.
#Flashing lights model drivers
As a result, first response workers are at higher risk for being injured or killed in vehicle crashes because approaching drivers cannot see them. Anecdotal evidence suggests that public safety agencies select emergency lighting systems with red or blue flashing lights based on their apparent brightness, with brighter lights judged as "better." With the advent of light emitting diodes (LEDs), emergency flashing lights are brighter and produce more highly saturated colors, thereby causing greater discomfort and disability glare. Flashing emergency lights on police cars, fire trucks, and ambulances need to be bright enough to alert otherwise unaware drivers about their presence on and near the roadway.
