US Route 50 was one of the major east–west transcontinental highways in the grid system of the lower 48 states planned in the 1920s as a successor to the National Auto Trails System. It extended from San Francisco, California to Annapolis, Maryland (later extended to Ocean City, Maryland). Route 50 crosses Virginia near the state's northern borders with Maryland and West Virginia. The east–west major routes in the 1920s national grid system were those with two digit numbers ending with a zero (i.e. US 10, US 20, etc.). Virginia's other east–west highway of this type is US 60, which extends in modern times from Virginia Beach across the middle section of the state to exit west of Covington.