Flashing lights for assistance vehicles – is red best?

It is widely believed that vehicle-mounted lights are effective in making vehicles more visible/conspicuous to other road users. For roadside workers, conspicuity is their first, and often only, line of defense. Following numerous near misses and impact incidents involving vehicles operating on high-speed (>80km/h speed limit) roads, RACQ trialed red flashing warning lights with the existing yellow flashing warning lights, comparing traffic speed and passing behavior.