Constitution Avenue is part of the National Highway System. 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 6th Street NW (eastbound) and 9th Street NW (westbound). U.S. 1 northbound uses the eastbound lanes of Constitution Avenue NW from 14th Street NW to 6th Street NW; southbound U.S. 1 used to run west from 9th Street NW to 15th Street NW but now continues straight through the 9th Street Tunnel to I-395. Locations of interest along Constitution Avenue Constitution Avenue NW is bordered by a number of important buildings and attractions. Beginning in the west are several independent federal agencies and institutes, as well as the headquarters of several large associations. These buildings include the United States Institute of Peace Headquarters, the American Institute of Pharmacy, the National Academy of Sciences, the Federal Reserve, the Department of the Interior, and the Organization of American States. The Ellipse, part of the grounds of the President's Park (which includes the White House), also borders the north side of Constitution Avenue NW and forms the boundary between the western and eastern segments of this part of the street. To the east on the north side is Federal Triangle, which contains the headquarters of a number of federal agencies. These include the Department of Commerce, Department of Justice, Environmental Protection Agency, Federal Trade Commission, Internal Revenue Service, and National Archives. The Embassy of Canada and John Marshall Park are located further east of Federal Triangle. Once past Pennsylvania Avenue NW, the E. Barrett Prettyman United States Courthouse, George Gordon Meade Memorial, and Department of Labor headquarters, and Senate Park border the north side of the avenue. On its south side, Constitution Avenue NW is bordered by several monuments and museums. These include Lincoln Memorial, Vietnam Veterans Memorial, Constitution Gardens, and the grounds of the Washington Monument. The relocated U.S. Capitol Gatehouses and Gateposts are at Constitution Avenue NW and 15th Street NW. East of the grounds of the Washington Monument are several museums: the National Museum of African American History and Culture (under construction as of 2013), the National Museum of American History, the National Museum of Natural History, National Gallery of Art Sculpture Garden, and the National Gallery of Art. Once past the National Gallery of Art, the ground of the United States Capitol border the