Route 15 is a bus route operated by the Maryland Transit Administration in Baltimore and its suburbs. The line currently runs from Security Square Mall, Westview Mall, Windsor Hills, or Walbrook Junction (all in West Baltimore or Baltimore County) through downtown Baltimore and northeast to Overlea, with selected peak hour express trips to Perry Hall. The main roads on which it operates include Security Boulevard, Windsor Mill Road, Forest Park Avenue, Poplar Grove Street, Edmondson Avenue, Saratoga Street, Gay Street, and Belair Road, and is one of the most heavily used bus routes operated by the MTA.