A step deck trailer, also known as a drop deck or lowboy trailer, is a commercial trailer designed to carry tall cargo that exceeds the legal height limit if transported on a traditional flatbed trailer. Transporting tall cargo on a step deck might prevent drivers and operators from having to obtain permits. Disclaimer Our content is not in any way legal advice or binding. The information provided by might not be the official legal or full definition. Also when pursuing a specific transaction you are encouraged to conduct your own due diligence and to consult legal counsel as appropriate.