In the United States and most other countries, turn signals are required on all vehicles that are driven on public roadways. They are required to blink on and off, or flash at a steady rate of between 60 and 120 blinks per minute. Regulations require that all turn signals must activate at the same time and flash in phase with one another, and that audio or visual warning be provided to the vehicle operator in the event of a turn signal’s failure to light. This warning is normally a much faster or even a slower than normal flash rate.
Until the early 1960s, front turn signals worldwide had a white light and the rear had red. In 1963, amber front turn signals were adopted in the United States for most vehicles, although front turn signals still had to a white light until 1968.
Now days in countries outside North America require that all front, side and rear turn signals produce amber light. In North America they can be either amber or red. International proponents of amber rear signals say that they are easily visible as turn signals if they are amber. But, US studies in the early 1990s demonstrated improvements in the speed and the accuracy of following drivers’ reactions to brake lamps when the turn signals were amber rather than red. And they claim that there is no proven lifesaving benefit to amber signals.
In countries outside North America, vehicles must be equipped with side mounted turn signals just to make sure that the turn indication is made visible laterally rather than just to the front or to the rear of the vehicle. Some vehicles, such as large pickups and SUVs, have been fitted with turn signals that are integrated into the side mirrors.
Just like all vehicle light and signaling devices, the turn signal lights must comply with technical standards that stipulate minimum and maximum permissible intensity levels and minimum horizontal and vertical angles of visibility, so that they are visible at all relevant angles.
Sequential turn signals was used on some past model vehicles where multiple light produce the rear turn signal do not all flash on and off in phase. This has only really been found on American vehicles that use a combination of red rear brake and turn signal lamps.
Stop lamps are a red colored steady burning rear light. It’s brighter than the tail lamps are they are active when the driver applies the vehicle’s brakes. They are called brake lights or stop lamps. The have to be fitted in multiples of two, symmetrically at the left and the right edges of the rear of every vehicle. In North America, the acceptable range for a single-bulb brake lamp is 80 to 300 candela.
In North America, a central brake lamp, that is mounted higher than the vehicle’s left and right brake lamps, has been required since 1986.
Reversing lamps provide illumination to the rear when backing up. This warns adjacent vehicle operators and pedestrians that the vehicle is in a rearward motion. Every vehicle has to be fitted with at least one rear mounted, rear facing reversing lamp, also known as a back up light. They produce a white light.