Due to many missteps, Sound Transit shortened the line in 2001 from the original 21 miles (34 km) to 14 miles (23 km), truncating the line to Downtown Seattle. In 1999, Sound Transit chose their preferred route for the light rail system, including a 4.5-mile-long (7.2 km) tunnel between downtown, First Hill, Capitol Hill and the University District with a crossing under Portage Bay the tunnel under Portage Bay was later deemed too costly and risky in 2000, and later dropped in favor of alternative options crossing the Montlake Cut.

However, Sound Transit in the 1990s was plagued with continually escalating costs, include an agreement with the University of Washington to install dampeners on the rails that run under the science buildings, air cushions to tables in the science buildings, and to mitigate environmental impacts due to construction and traffic impacts from having the station on university grounds. Planning and funding Ĭonstruction of light rail was originally proposed in the 1996 Sound Move measure, with plans to open a line from Seattle–Tacoma International Airport to the University District in 2006. Light rail service began on March 19, 2016. The 21 ft-wide (6.4 m) tunnels are lined with precast gasketed concrete segments connected with steel bolts and was excavated using three tunnel-boring machines in 20. The twin-bore tunnel carries Link light rail service on the University Link Extension of Central Link (now the 1 Line), running from the Downtown Seattle Transit Tunnel to University of Washington station via Capitol Hill station. The University Link tunnel is a 3.15-mile (5.07 km) light rail tunnel in Seattle, Washington. A section of tunnel at Capitol Hill station

Capitol hill light rail