The Washington State Department of Transportation (WSDOT) in the US is looking for design-builders to build a new State Route 520 floating bridge across Lake Washington.

The design-build contract, worth $700m-$900m, is for a new six-lane bridge with transit/HOV lanes and a bicycle/pedestrian path.

The floating bridge will be connected to fixed bridges on both sides of Lake Washington and will have 44 supplemental pontoons and 58 anchors.

WSDOT said its I-5 to Medina bridge replacement project includes the floating bridge project and when completed, will improve travel times and reliability on the corridor.

WSDOT will issue a request for proposals in October; the new bridge is scheduled to open in 2014.