SAN FRANCISCO (Standard&Poor's) Sept. 14, 2012--Standard&Poor's Ratings Services has assigned its 'AA' long-term rating to the District of Columbia's $43.3 million series 2012 federal highway grant anticipation revenue (GARVEE) bonds. At the same time, Standard&Poor's affirmed its 'AA' long-term rating on the district's GARVEE bonds outstanding. The outlook is negative. "The rating reflects our view of strong future debt service coverage based on historical federal grant receipts and a sound bond structure," said Standard&Poor's credit analyst Mary Ellen Wriedt. All federal highway revenues that the district receives are pledged to the payment of the bonds; in addition, the existing series 2011 bonds have a debt service reserve account equal to maximum annual