The Radar Message Director is a versatile, all LED changeable message sign capable of displaying messages in alphanumeric text or arrow board patterns and radar output to remind motorists to check their speed (up to 3 digits may be displayed in either MPH or km/h format). The approach-only radar system detects only oncoming traffic. An automatic brightness feature gives the sign a legible viewing distance of over 600ft (183m) both day and night. The sign is used in a variety of locations including school zones, construction or maintenance work zones, neighborhoods and high-accident areas where the speed limit must be enforced.