I think the rear ditch lights are.very practical. If the unit is running alone they are handy. The best part is that the unit can lead at full speed running backwards. This sometimes happens when a consist is put together, all units face the same way, and there is no place to turn one. In emergencies a unit may not be able to lead due to accident or airbrake failure enroute. If ther are no ditch lights, the unit must not exceed 20 mph over crossings.