The DSTT is open for 20 hours on weekdays and Saturdays, from 5:00 am to 1:00 am the following day, and for 18 hours on Sundays, from 6:00 am to midnight. At the time of its opening in 1990, the Metro Bus Tunnel only operated from 5:00 am to 7:00 pm on weekdays and 10:00 am to 6:00 pm on Saturdays, with no Sunday service; the operating hours were temporarily extended into weekday nights from 1998 to 2000 at the request of the Seattle Seahawks and Seattle Mariners, but were cut after the passage of Initiative 695 and subsequent loss of motor vehicle excise tax revenue. Preparations for Link light rail service restored late-night and full weekend hours for the tunnel, introduced in June 2009 after Sound Transit Express route 550 moved all of its trips into the tunnel.