When the wheels of a trailer lock up: Question When the wheels of a trailer lock up: Answers The trailer will stay straight. The trailer tends to swing around. The cab will swing, but the trailer will stay straight. They will likely go flat. Explanation A trailer may swing out and strike other vehicles if its wheels lock up. This is especially likely with lightly-loaded trailers. This questions appears in the following tests: District Of Columbia Combination Massachusetts Combination Minnesota Combination New Hampshire Combination Oregon Tank West Virginia Tank Wyoming Double