Complete ELDT Class A CDL Practice Exam 2026

To operate a commercial motor vehicle (CMV) in interstate commerce, a person must be at least 21 years old. This age requirement is established by federal law to ensure that drivers have reached a level of maturity and responsibility that is deemed necessary for handling large and potentially hazardous vehicles on the highways. Those under 21 are allowed to operate a CMV in intrastate commerce (within one state) but are prohibited from doing so in interstate operations, which involve crossing state lines. This distinction aims to enhance safety on the roads by setting a higher age threshold for interstate operations, where the risks can be greater due to long-haul driving and the complexity of navigating varying traffic laws across different states.