The tunnel carries a segment of Line 1, which runs from the University of Washington station through Downtown Seattle and the Rainier Valley to Seattle–Tacoma International Airport. Trains serve all downtown tunnel stations 20 hours a day every day; during regular weekday service, trains run roughly every six to 10 minutes during rush hour and midday operation, respectively, with longer headways of 15 minutes in the early morning and 20 minutes at night. During weekends, Line 1 trains arrive every 10 minutes during midday hours and every 15 minutes during mornings and evenings. Light rail service from Westlake to International District/Chinatown takes approximately seven minutes.