On low bridges: Question On low bridges: Answers Height warnings must always be posted. Height warnings must be posted at least twice. Height warnings may be posted, but do not have to be. Explanation Height warnings are often, but not always, posted on low bridges. If you are unsure if you will be able to clear an overhead object, go slowly. This questions appears in the following tests: Minnesota Class B Knowledge Test Nevada Class B Knowledge Test Nevada Double South Carolina Class B Knowledge Test South Dakota Tank Wyoming Double
