A highway/railroad crossing detection and warning system which uses sets of Doppler radar transmitters and receivers to detect the approach of a train coming from either direction toward a highway crossing. The Doppler radar sets are located an extended distance from the crossing with each set detecting movement toward and away from its location. Presence detectors are located at the crossing and sense moving or stationary trains. All detector devices transmit signals to warning equipment to provide aural and visual indications to approaching motorists or work crews.