Abstract: A speed limit indicator for, for example, a four-lane highway (1) having left lanes (3) and right lanes (4), the direction of travel indicated by the arrows. Road markings (11, 12 and 13) of different colors are used to provide an indication of the speed limit for the particular speed zone. The invention also provides a transmitter which is sited usually at the entrance to a speed zone and a receiver in a vehicle which are used to signal the speed limit to a driver.