The Sound Transit Board Thursday, April 25, culminated a 16-month collaborative process with city of Bellevue officials and community members by unanimously approving refinements to the alignment for the East Link light rail extension.

The changes will support the partnership to construct a tunnel in downtown Bellevue by reducing costs by an estimated $30 million to $53 million.

“Today’s action brings certainty to the East Link project and enables us to move the entire alignment into the final design process,” said Sound Transit Board Chair and Pierce County Executive Pat McCarthy. “By working together in a spirit of collaboration and compromise we have created a major win for riders and City of Bellevue taxpayers and can move forward toward the 2023 opening.”

Claudia Balducci, a member of both the Bellevue City Council and Sound Transit board, said the agreement is a win-win situation.

“On both sides of Lake Washington this project will change people’s lives by cutting through congestion with fast and reliable light rail,” Balducci said. “Link will also help us attract more high-quality jobs.”

The changes were endorsed 6-0 by the Bellevue City Council on Monday, April 22.

“We are pleased with the Sound Transit Board’s decision today to accept the city council’s cost-savings recommendations on how to bring East Link into Bellevue,” said Bellevue Mayor Conrad Lee. “While the process has been challenging at times, we have worked with the public and Sound Transit to assure the project reflects the best interests of our residents, neighborhoods and businesses. Today’s actions are the result of our collaboration.”

The changes include a fully at-grade alignment along 112th Avenue Southeast south of downtown. As the route moves north from South Bellevue Way and turns east onto 112th Avenue Southeast it will pass beneath a raised section of 112th at Southeast 15th Street to reach the west side of the roadway.

A street-level crossing of Southeast Fourth Street will allow only emergency vehicle access into the Surrey Downs neighborhood at that location. Bellevue had earlier proposed a trench alignment along 112th. The updated alignment is estimated to save $2 million to $4 million.

As previously planned, trains will travel north through downtown Bellevue in a tunnel under a cost-sharing agreement between Sound Transit and the city that shortens travel times while improving the flow of vehicle pedestrian traffic on the surface. The refinements replace a previously planned underground station with a daylight station located slightly further north as the tunnel turns east onto Sixth Avenue and transitions to an elevated alignment in preparation to cross I-405. The change will save an estimated $19 million to $33 million.

Other refinements identified through the process will save an estimated $9 million to $16 million. Sound Transit’s work to advance engineering and secure permits will move forward under city of Bellevue land use changes that make the light rail extension a permitted use.

The collaborative process followed the board’s November 2011 adoption of the previous East Link alignment and entering into a memorandum of understanding with the city that created a framework to focus on identifying up to $60 million in reductions to the city of Bellevue’s up to $160 million contribution for the tunnel.

Along Bellevue Way, Sound Transit and the city of Bellevue considered potentially moving the light rail alignment from a trench north of the South Bellevue Park and Ride near the Winters House to an at grade alignment, as well as the possibility of coordinating construction of a new city HOV lane on Bellevue Way with the light rail project. The option would have required moving Bellevue Way to the west and constructing a retaining wall between the road and the Enatai neighborhood.

The Link alignment will remain in a trench. The city of Bellevue will independently evaluate and be responsible for any future construction of an HOV lane.

In addition to enabling the final design process to move forward, the action also positions the Sound Transit Board to take action within the next two months to authorize the beginning of property acquisition for constructing East Link.

Sound Transit is working to start construction in 2015 and launch passenger service in 2023. The project is estimated to create more than 20,000 direct, construction-related jobs over the duration of the work and 34,000 to 42,000 indirect jobs as the stimulus spreads throughout the economy.

The East Link alignment was shaped by more than 2,500 comments since 2006. Sound Transit held 35 open houses, hearings and workshops and shared information and answered questions at 38 Eastside fairs and festivals. Stakeholders and property owners have received information at more than 300 smaller meetings and briefings.

Riding East Link between Seattle and downtown Bellevue is projected to take less than 20 minutes. By comparison, in the afternoon peak period it can currently take approximately 45 minutes to travel between Seattle and Bellevue via I-90.

As the region’s population continues growing, East Link will have the capacity to increase the length and frequency of trains to carry from 9,000 to 12,000 people per hour in each direction, which would more than double the person-carrying capacity of I-90 and is roughly equivalent to seven to 10 freeway lanes of vehicle traffic. By 2030 East Link is projected to carry more than 50,000 riders each weekday.