See this message from WMATA's Ann Chisolm;
Effective Sunday, December 30, 2012, Metrobus Route 80 will be detoured in the southbound direction toward Kennedy Center via the North Capitol Street tunnel under New York Avenue in order to improve safety for buses in response to several accidents at the intersection of North Capitol Street & New York Avenue. As a result, southbound 80 buses will not be able to serve the stops at New York Avenue and at M Street. Buses will continue to serve stops at P Street and at Pierce Street. Northbound buses will continue to operate on the service road at New York Avenue and serve all existing stops.
Ann E. Chisholm
Office of Government Relations
Government Relations Officer for the District of Columbia
Washington Metropolitan Area Transit Authority
600 5th Street, NW
Washington, DC 20001