SR 543, I-5 to International Boundary

The Blaine Border Crossing between Washington State and British Columbia has the third highest volume of passenger traffic and the fourth highest volume of commercial trucks along the entire U.S.-Canada border. This $33 million dollar project widened the highway and built a new overpass to relieve congestion, improve safety and facilitate truck movement across the border.

With the significant elevation differences of the existing roadway to 25 feet lower in the final design, Imco used machinery equipped with GPS. The machinery eliminated the need for construction surveying, and was able to excavate and grade at the precise plan elevations within +/- 100th of an inch. The D St. overpass bridges were built on grade, the bridge deck poured, and only then did contractors proceed to excavate beneath the completed bridges. This was not only an innovative approach to construction, but a more efficient, safer technique.

Imco excavated over 200,000 cu yds of export material, lowered the road 25 ft., poured 34,142 cu yds of concrete, built two bridges on grade for the new interchange at D Street, constructed a designated truck lane and drilled 1,000 concrete shafts. Despite the fact that all work took place while the roads were open, large traffic volumes were maintained and border wait times kept to a minimum, an achievement that took many hours of planning and communicating with numerous parties.

Key Players

Owner: Washington State Dept. of Transportation
General Contractor: IMCO General Construction, Bellingham
Subcontractors: Granite NW-Asphalt Pavement; Sail Electrical-Electrical; Condon Johnson-Concrete Piling and Acme Concrete Paving-Cement Conc. Pavement