SR 522 - Snohomish River Bridge to US 2, Four Lane Widening - Rock Blasting

To create space for a widened SR 522 roadway, we removed 327,000 cubic yards of rock along the westbound lanes. We blasted the rock using explosives and then the conrtractor hauled it away from the site.
By the numbers:

  • 327 thousand cubic yards: amount of rock and dirt removed
  • 12,000: number of truckloads required to haul the rock and dirt
  • 50 tons: estimated weight of each load hauled
  • 46: blasts

SR 522 was closed during blasting and drivers detoured around the site. Download a flyer (pdf 728 kb) about our rock blasting work (pdf 1 mb) or watch a video (YouTube).

Rock near SR 522

Each blasting operation lasted about an hour from start to finish and was done only during daylight hours for safety. To keep drivers safe we fully closed the roadway in both directions during the blasting work. Closures generally occurred every Tuesday and Thursday from 10:15 to 11:15 a.m.  


Detour map

Detour route for SR 522 closures
Drivers used an alternate route or followed a signed detour using SR 9 and US 2 around the closure. The detour added 10 miles and 20 minutes to trips, depending on destination and traffic. We used electronic signs and highway advisory radio to alert drivers to the closures.