The A1X is a bus rapid transit (BRT) line operated by the Washington Metropolitan Area Transit Authority (WMATA) as part of their Metrobus system. It operates in Arlington and Alexandria, Virginia. It opened on August 24, 2014, and was the first bus rapid transit line to open in Virginia and in the Washington metropolitan area. On June 29, 2025, Metroway was renamed as route A1X during WMATA's Better Bus Redesign.