The seasonal clearing and reopening of State Route 20 – North Cascades Highway marks an important day for recreationalists, families, drivers, adventure seekers and tourists who enjoy scenic east-west travel across the state. However, this isn’t the only thing happening on SR 20 between Sedro-Woolley and Winthrop this year. WSDOT crews and contractors will be making emergency repairs, performing important maintenance and preservation work and fish passage construction this year, with more work to come in the years ahead. As you plan your travels across this scenic highway this year, please take a look at the work we are doing so that you can plan ahead.
Emergency repairs between Marblemount and Newhalem
The winter floods of 2021 damaged SR 20 in four locations between mileposts 101 to 116. Most of the repair work has been completed with the exception of a significant wash out in the eastbound lane at milepost 113.7, just west of Sky Creek. Traffic in both directions along this stretch of highway is controlled by a temporary traffic signal and has been alternating both directions of travel through the westbound lane, which did not sustain damage.
Evaluating the damage and planning the repairs
Crews needed to understand what was happening beneath the surface, how much the roadway was settling and the makeup of the soil and sediment in this area in order to determine the best way to repair it.
In December 2021, crews spent several weeks drilling samples of subsurface material and then our experts analyzed the data taking into account things like earth pressures, resistance, drainage and stability. We are working to finalize the design of a soldier pile and tieback wall which will be delivered as an emergency construction contract. These repairs are expected to begin by mid-summer which means that traffic will continue to alternate in the westbound lane for the next several months. Travelers heading across the pass should expect delays throughout the summer. Our crews will be evaluating the timing of the signal for maximum efficiency and will adjust accordingly to help with the flow of traffic.
NWR Emergency Pavement Repair
Sometimes extreme winter weather results in the need for urgent and unplanned repairs. The flooding and freezing that took place during the 2021 winter season resulted in an emergency contract for pavement repair across 15 state highways in four counties, including along SR 20 in Sedro-Woolley near Helmick Road and again in a mile long stretch between Neilson Lane to Pinelli Road.
Later this summer contractor crews working on behalf of WSDOT will use a hot liquid asphalt mix to seal active cracks in all lanes both eastbound and westbound along this stretch of highway. They will also repair and fill potholes in this area.
What should travelers expect
Travelers should expect eastbound and westbound traffic to alternate through a single lane with flaggers directing traffic through the area. Delayed travel times are expected and drivers are asked to follow all posted signage and directions of traffic control officers.