Humped crossings or high-profile crossings are a highway-rail intersection where the road surface profile across the rail tracks may pose a risk to a low-clearance vehicle becoming stuck on the tracks, as well as block drivers’ vision of the road ahead. Types of vehicles that, due to low clearances or long overhangs, may become centered or 'hung-up' include: some schools busses, trucks hauling hazardous material, as well as various types of farm equipment. They may also pose a threat to heavy vehicles that are required to stop at the crossings due to steep grades.
States are required to identify high-profile crossings, sign them appropriately, and keep their information in an electronic database. In 1997, the Federal Highway Administration adopted a new advance symbol sign for crossings, however, there is no standard procedure at the federal level on how to identify such crossings and most humped crossings remain unsigned, leaving drivers with the decision of judging whether or not they can clear the crossing safely.
"Bad Crossings Kill Good Drivers"®