Constitution Avenue - Route Numbers

Route Numbers

Sections of Constitution Avenue are designated U.S. Route 1, U.S. Route 50, or both. Specifically, U.S. 50 runs along the road from its west end to Sixth Street NW (eastbound) and Ninth Street NW (westbound). U.S. 1 northbound uses the eastbound lanes of Constitution Avenue from 14th Street NW to Sixth Street NW; southbound U.S. 1 used to run west from Ninth Street NW to 15th Street NW but now continues straight through the Ninth Street Tunnel to I-395.