Question If an Anti-Lock Braking System (ABS) is equipped on a trailer but not on a tractor: Answers The truck should not be driven because ABS needs to be on both the tractor and trailer. The truck should be driven more slowly than usual. The tractor should not be used and a new tractor with ABS should be located. The tractor and trailer can still be used together. Explanation A vehicle being equipped with anti-lock brakes on only the tractor or only the trailer provides additional control during braking. Take a FREE Practice Test Now This questions appears in the following tests: Pennsylvania Knowledge Test Class A , West Virginia Knowledge Test Class B ,