Final answer:
A red lantern on the rear of a car on a lay-up track signals that the car is stopped or parked.
Step-by-step explanation:
A red lantern on the rear of a car on a lay-up track is an indication that the car is stopped or parked. This safety signal is essential in various transportation settings, such as railways and some road scenarios, to alert other vehicles or personnel that a car is not moving and should not be approached from behind. Similar rules in traffic management may dictate that a vehicle display a red light to indicate it is stationary or that it is an obstacle to be cautious around.