The Washington State Department of Transportation (WSDOT) as its general engineering consultant for design improvements has selected URS CORP. for I-90, the most important east-west corridor in the state, linking Puget Sound to eastern Washington and beyond.
Traffic on the interstate has been growing at a rapid rate and now exceeds the original design volume. In addition, the pavement has deteriorated and has extensive cracking, there are areas of reduced sight distance and sharp curves that limit safe vehicle operating speed, and rock slides and avalanches have made it necessary to close the interstate at times until safe conditions could be restored.
The project, which involves a 15-mile segment from Hyak to Easton, includes:
- Realignment of the interstate where necessary to improve sight distance, design speed and traffic capacity;
- Replacement, overlaying and/or construction of new pavement to upgrade from four lanes to six;
- Mitigation measures for rock stability to minimize the risk of rock slides;
- Avalanche studies, roadway alignment and mitigation measures to prevent road closures;
- A new bridge and wall structures necessary for safety improvements;
- Construction of structures to make it safe for wildlife to cross the interstate;
- Improvement of chain-up areas; and
- Improvement of intelligent transportation systems used to inform the public of accidents, hazardous driving conditions and impending snowstorms.
URS will work with WSDOT, the U.S. Forest Service, the U.S. Department of Fish and Wildlife and other agencies to prepare the final Environmental Impact Statement. The project is being supported by environmental groups as a result of the commitment to provide ecological connectivity locations for wildlife in the area.
Design of the $387 million project began in late spring; construction is scheduled to start in the spring of 2010.