Contact: 1-800-832-5660 or (225) 757-7640
You are required to provide a U.S. DOT number at the time of registration if your vehicle has a combined gross weight over 10,000 pounds and:
- is used for commercial (business ) purposes, or
- has farm registration and crosses the state line
This number, from the U.S. DOT, is issued to the party (individual or company) responsible for the overall safety of the vehicle.
Also provide the Federal Motor Carriers Safety Division website for further information http://www.fmcsa.dot.gov/