Signal or message boards are helpful and even life saving devices when people and equipment must need work on public or even private roadways and highways. Signal or message boards are commonly recognized by the public at large and they respond accordingly. Signal or message boards come in a wide variety of shapes, sizes for singular or multiple purposes. Signal or message boards may be permanently affixed to a single location as in an amber alert message board or may be mobile as in the police speed detection signal board.
In construction or engineering signal and message boards tend to be mobile. They are attached to a trailer and consist of a series of lights that may be programed to convey a message or a signal. Such as 'lane closed ahead move left' or as simple as a signal showing moving arrows indicating that drivers should move over one or more lanes.
Signal and message boards are powered in several different manners. They can operate from a generator, they operate from the vehicle towing the trailer or they may operate on a set of serial batteries. There are many manufacturers of signal and message boards most notable is Signal and Amida.