How many lights do you need on trailers?

Answer 1

on a commercial trailer you need a minimum of four tail lamps (two for brake two for signals and all four must work as running lights)

red lamps marking the rear corners of the trailer and a minimum of three red identification lamps

on trailers over 28 feet in length you need mid markers and mid turn lamps (amber)

at the front of each trailer you need amber clearance lamps

and you ABS indicator lamp must function

also the bumper and the side rails of the trailer require DOT approved reflective tape

this is the minimum set up any additional lamps added must be functional once they are added