Transportation in Arkansas is overseen by the Arkansas Department of Transportation (ArDOT), headquartered in Little Rock. Several main corridors pass through Little Rock, including Interstate30 (I-30) and I-40 (the nation's 3rd-busiest trucking corridor). Arkansas first designated a state highway system in 1924, and first numbered its roads in 1926. Arkansas had one of the first paved roads, the Dollarway Road, and one of the first members of the Interstate Highway System. The state maintains a large system of state highways today, in addition to eight Interstates and 20 U.S. Routes.