If you ride anywhere near a road at night, you can limit risk with a reflective harness. A durable nylon-webbing harness has reflective material on the crown, cheeks and nose for high visibility. Adjustable at the curb and snap at the throat allows you to make this comfortable for your horse.
High visibility allows motorist to take precautionary measures when approaching you. They may even slow down with confusion unsure of what they are actually seeing! Remember all they see is reflective light!