A bill that would allow CDL holders under the age of 21 to cross state lines has been filed in the U.S. Senate. The Drive-Safe Act, which was also filed in the U.S. House in March, would institute extra training hurdles and require 18-20-year-old drivers to log hundreds of hours behind the wheel alongside a more experienced driver before being permitted to operate interstate. The bill is backed by the American Trucking Associations. Currently, federal law prohibits interstate operations to drivers 21 years and older. However, proponents of allowing younger drivers to cross state lines argue that, in large states, drivers can operate on trips hundreds of miles long, yet can’t make much shorter trips across multiple states. They also argue that nabbing drivers at an earlier age — 18 or 19 instead of 21 — could expand the industry’s ability to attract career truck operators.