Adding victory to victory, the federal government gave its stamp of approval on the final light-rail route today, just two days after Bellevue signed off on it.

The Federal Transit Administration’s decision was the culmination of five years of deliberation on where the East Link Route should go.

“November 2011 will be remembered as a turning point in the history of transit for the Eastside,” said Dow Constantine, the King County Executive. “Now it’s time to finish the design and start construction.”

The decision also wraps up the environmental study and public input for the route, which began in September 2006. During the process, Sound Transit received over 1,800 comments and held 28 open houses.

The support from the FTA allows Sound Transit to move into the final design process, which would take a train across I-90, through Downtown Bellevue and into Redmond.

Bellevue signed off on an agreement earlier this week to build a blueprint to construct a downtown tunnel and begin a collaborative design process with Sound Transit.

The decision comes too after the Washington State Department of Transportation agreed Nov. 3 to give up I-90s current HOV lanes for the route. To fill the void, Sound Transit is funding the construction of a new HOV lane to both the east and west sides of I-90 between Bellevue and the floating bridge into Seattle.

“East Link will improve people’s commutes on both sides of Lake Washington while stimulating our local economy and making us even more attractive for new employers,” said Claudia Balducci, who serves on both the Sound Transit board and as a Bellevue councilmember.