Commercial Driver's License

Answer: D - Tapping your brake lights is a good way to signal to other drivers that something is happening ahead or about to happen. Many drivers behind a large commercial vehicle will not be able to see what is happening on the road ahead, and tapping the brake lights gives them some warning. Commercial drivers can tap their brakes when they see trouble ahead; when they see another vehicle, including school buses, stopping in the road; and when approaching railroad crossings in which the commercial driver may or may not have to stop.