If backing at night and the camera doesn't work or we do not trust the camera then we use the following procedure.First, get out and walk around the area you are about to back up in. Second, identify spots or issues that may get the bus stuck or someone injured.Third, get out the little hand held walkie talkies. Turn off inside lighting. Let eyes adjust.Fourth, backer turns on flashlight and uses only agreed upon signals along with voice prompts.Fifth, go slow!Sixth, go slow!Seventh, if any serious problems are considered or a real possibility of injury. Stop wait until sunlight or move to a better location.