What is the first step a Dispatcher must take when notified of a malfunctioning automatic highway crossing device?

The initial action a Dispatcher must take when notified of a malfunctioning automatic highway crossing device is to stop all trains approaching the crossing. This step is critical for ensuring the safety of both train operations and roadway users. Stopping trains prevents potential collisions and allows for a thorough assessment of the situation.

In the case of a malfunction, the integrity of the warning signals and barriers cannot be guaranteed, which poses a significant risk. By halting all trains, the Dispatcher can effectively manage the situation, coordinating with maintenance teams or other authorities to resolve the issue safely before resuming operations. The priority in such scenarios is always the safety of passengers, crew, and personnel on the road, making this precautionary measure paramount.

Other options, such as informing trains to bypass the crossing or sending maintenance crews without first stopping approaching trains, do not address the immediate safety concerns adequately. Moreover, delaying all train schedules might be necessary later, but the first and foremost action must prioritize the safety of the trains approaching the malfunctioning device.