If you operate a vehicle meeting the definition of a commercial vehicle, the answer is yes. This number is assigned to those carriers, both for hire and private, that operate commercial vehicles in interstate as well as in intrastate commerce. If you are a private carrier, operating solely in intrastate commerce (your vehicles never leave the state) you are required to have a USDOT number assigned to your company and mark that number on your vehicles. However in this case, there is not an agency in the state authorized to give those USDOT numbers to private carriers operating solely in intrastate commerce. You are required to have that number, but there is no place for you to seek remedy at this time.