• Report Home
• Evaluation Criteria

Project Evaluation: I-90, SR 26 Interchange Ramp Improvements

Grant County
The Interstate 90 and SR 26 interchange was a high accident location.  Short, steep, and sharply curved ramps to and from SR 26, coupled with frequent high winds through the Columbia River Gorge at Vantage, caused many serious accidents. 

The project realigned and lengthened the eastbound and westbound on and off ramps to provide standard-length merge lanes. Along with the ramp improvements, electronic motorist information signs were installed east of the interchange on I-90 to warn westbound vehicles of high winds and other road conditions at the gorge ahead.

Design:  Construction Management: Schedule: Cost:   Engineer’s Estimate: $4,327,142   Contractor's Bid: $4,176,465   Anticipated final payment to contractor: $4,075,000

Construction Summary
Our working relationship with the contractor was good and problems were addressed in a timely manner.  The project was built according to the original design, with some changes made to the construction staging in order to keep traffic moving better. These changes added an extra 23 working days to the schedule. Despite this, the project was substantially completed on September 30, well ahead of the originally planned mid-October timeframe.

Construction timing for the new ramps was critical due to high traffic volumes and the need to protect motorists during the more than 50 controlled rock blasts. As work progressed, discussions took place frequently about how best to overcome obstacles and stay on schedule.  The team successfully avoided major delays or closures during peak traffic hours while meeting our target of  having the ramps open by Labor Day. 

Extensive traffic control was needed during the controlled blasts, which were used to remove rock from the area of the new westbound ramps. During blasting, both eastbound and westbound lanes on I-90 and SR 26 had to be closed for safety and 30-minute rolling slow downs were instituted.  Highway Advisory Radios (HARs), electronic message boards and flaggers helped to inform and direct the traveling public through all phases of construction. 

The traffic control plan and the work zone safety plans were successful in that there were no WSDOT or contractor personnel injuries reported during construction and no project related vehicle accidents. 

Contractor:

Steelman-Duff, Inc.

1490 Fair Street

Clarkston, WA 99403

WSDOT Contact:

Joel D. Voth , Project Engineer

PO Box 98

Wenatchee, WA  98807

(509) 667-2870

Visit the I-90/SR 26 Ramp Improvements Web page for more information, photos and maps.

back to top