Construction on the Eastside portion of State Route 520 in the US state of Washington will begin in early 2011.

The State Route 520 project is expected to replace the Evergreen Point Bridge and the Portage Bay Bridge.

The project, worth $4.35bn, will also involve major highway improvements along the 520 corridor, according to

Upgrade work involves building three lids over the freeway, a new bridge at Bellevue Way, an enhanced regional bike trail and noise walls.

Other works include replacing the floating bridge, landings, interchanges and roadway in Medina.

Work is expected to be completed in 2014.