Grade Crossing NRC (no road crossing) traffic stopper. A traffic stopper that can be used along with my NRC grade xing lights to stop the traffic. The ATLS slave, trigger and controller must be used with this traffic stopper. For more information visit http://www.boatztrainz.co.uk/. The road connections are set at 0.0. My grade crossing plates can be placed on the tracks to fill in for a smooth crossing for the cars.