The Senate and the House have resurrected a controversial effort to allow truck drivers under 21 to drive across state lines.

Although 48 states allow 18-year-olds to obtain a commercial driver’s license, federal law bars them from driving across state lines until they are 21. Proponents of adjusting the federal rules argue that a truck driver under the age of 21 in California could drive anywhere within the state, up to hundreds of miles, but one in the Northern Virginia and Maryland area wouldn’t be able to drive even short distances.