No individual shall operate a commercial motor vehicle without a valid commercial driver’s license issued in accordance with section 31308. An individual operating a commercial motor vehicle may have only one driver’s license at any time and may have only one learner’s permit at any time.
(Pub. L. 103–272, § 1(e), July 5, 1994, 108 Stat. 1015; Pub. L. 105–178, title IV, § 4011(b)(1), June 9, 1998, 112 Stat. 407; Pub. L. 109–59, title IV, § 4122(1), Aug. 10, 2005, 119 Stat. 1734.)