International District/Chinatown station, the southernmost tunnel station, is partially open-air and located immediately below a public plaza at Union Station. The station has connections to Amtrak and Sounder commuter rail at King Street Station a block to the west, accessible through the Weller Street Bridge, as well as the First Hill Streetcar on Jackson Street, stopping east of 5th Avenue South. Other attractions near the station include CenturyLink Field to the west and Uwajimaya a block to the southeast. South of the station, the light rail tracks, and bus lanes are separated by railway signals at an underground bus layover and staging area next to the tunnel comfort room for bus drivers. The southern portal of the tunnel is located under the intersection of Airport Way and 5th Avenue South at the western terminus of the former Interstate 90 express lanes for high-occupancy vehicles. Light rail trains and southbound buses continue from the tunnel in separated lanes on the SODO Busway, while eastbound buses use a set of ramps that travel onto Interstate 90. Eastbound buses formerly used a ramp that merges with the Interstate 90 express lanes that closed in September 2018 and will be retrofitted for the East Link light rail service that begins in 2023 on Line 2.