Connecticut has adopted 390.21 of the he Federal Motor Carrier Safety Regulations (FMCSRs), by reference with subsequent amendments as they occur.
Section 390.21 applies to intrastate commercial motor vehicles with a gross vehicle weight rating or gross combination weight rating or gross vehicle weight or gross combination weight of 18,001 pounds or more, and to any size commercial motor vehicle transporting hazardous materials requiring placards.
The US DOT number must have the suffix “CT” if the carrier is an intrastate only carrier. Example: USDOT 123456 CT