limited number of trips during the early morning between 4am and 5am, while BART is closed. The K, L, and N Owl motor coaches replace daytime light rail service and run on surface streets, making local stops, rather than in the Market Street subway, Twin Peaks Tunnel, and Sunset Tunnel. The L Owl also covers the route of the daytime F-Market line. The L and N Owl buses run all night, while the K Owl runs only a small number of trips in the early morning and just after the subway closes. Early morning lines In addition to the Owl service, buses normally provide weekend service along all Muni Metro lines from 5am until rail service begins (6am on Saturdays, 8am on Sundays) to allow for overnight maintenance work in the subway. The K, L, and N Bus routes differ slightly from the nightly Owl routes and do not make local stops along their surface street detours, instead stopping only at stops used by the normal L and N daytime light rail routes. Several of the early morning routes are suspended, while the L bus operates the same shortened route as the daytime bus. References External links SFMTA - Muni Routes & Stops San Francisco Municipal Railway Muni Muni San Francisco Municipal Railway San Francisco