Some CDL regulations set by the Federal Motor Carrier Safety Administration include a requirement for states to test prospective CDL licensees with the specific type of vehicle they seek to drive and the requirement to obtain specific endorsements to drive certain types of vehicles, such as double and triple trailers, tank vehicles and hazardous material transports. Endorsements are obtained through additional knowledge tests, and in some cases skills tests.
Other CDL regulations include the requirement for commercial motor vehicle drivers to notify their current employer of certain criminal convictions. These regulations establish certain periods of disqualifications in addition to penalties for drivers who are convicted of serious traffic violations, including drug and alcohol-related charges. Additionally, these drivers are not allowed to hold commercial vehicle licenses from multiple states. This ensures that a driver may not be able to continue driving by using a secondary license, should his primary license be suspended due to an infraction.
While each state typically manages all requirements for licensing within its borders, the Federal Motor Carried Safety Administration promulgates minimum standards that each state must adhere to. Since commercial driving is a major interstate activity, the federal government's interest is ensuring that all commercial drivers are properly trained to operate vehicles under the different conditions that they might encounter across the country.