What device is designed to guide a car off the rails to protect against collisions or other accidents?

The device designed to guide a car off the rails to protect against collisions or other accidents is known as a derail. A derail is strategically installed on tracks at specific locations to help prevent trains from continuing forward in the event of a signal failure or other emergencies. By redirecting the train off the track, it minimizes the risk of collision with other trains or objects and effectively serves as a safety measure.

While the other devices serve important functions in rail operations, they do not perform the specific task of directing a train off the rails. Signals inform train operators of track conditions and safety, switches allow for the changing of tracks, and control arms are typically associated with crossing gates or other interface systems rather than derailment prevention. Hence, the derail plays a crucial role in railway safety by ensuring that trains can be safely managed in critical situations.