Constructing the full State Route 520 corridor from Interstate 5 to Redmond, including a new floating bridge and six-lane highway, is estimated to cost $522 million less than the 2009 legislative budget cap, the Washington State Department of Transportation said.

WSDOT finalized documents for a $300 million federal loan that will fund design and construction of the next portion of the SR 520 project – a westbound bridge between the west-end landing of the new floating bridge and Montlake.

At the same time, Transportation Secretary Paula Hammond ordered a review to fully understand the cause of concrete spalling and more-than-expected cracking in new pontoons.

Issues that occurred during the first cycle will likely lead to additional, yet-to-be-determined costs for repairs and schedule delays under discussion between the state and its pontoon and bridge-replacement contractors. Negotiations will take place over the next few months.