Bellevue City Council in the US has approved the Sound Transit plan to run light rail trains across the Interstate 90 floating bridge and underground tunnel into Redmond.
The $2.7 billion project will extend light rail 14 miles from Seattle, through Bellevue and to the Overlake area of Redmond.
Construction on the project is expected to start in 2015 and trains are scheduled to be running east of Lake Washington in 2023.
The memorandum of understanding (MoU) signed between the county and Sound Transit outlines the cost sharing strategy that will add an additional $276m to the project.
The city will finance $160m of the tunnel cost through tax breaks, property acquisition, cash and other actions.