Motor vehicle and pedal cycle conspicuity - part 3: vehicle mounted warning beacons. Final report.
Vehicle mounted warning beacons have developed from flashing tungsten filament bulbs through constant luminance bulbs with rotating reflectors to multiple, high intensity, strobe lamps with various phase options. Warning beacons are used on a number of types of vehicles, each undertaking its own range of tasks, to either alert other road users of their presence or warn of potential danger. With the wider use of flashing beacons, not just on vehicles but also for road works, it is necessary to review the current safety requirements and the regulations covering their use. Whilst this study has a broad ranging remit, of particular concern is the conspicuity of vehicles fitted with amber warning beacons (e.g. recovery vehicles) when they are in environments where other flashing amber lights are present.
Department for Transport