SR 542 - SR 9 East Junction - Intersection Improvements

Project news

  • WSDOT contractor crews from Colacurcio Brothers have started work on this project.
  • Work is expected to last until mid-June and flaggers will alternate travelers through this intersection around-the-clock during much of this construction.
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WSDOT will build a roundabout at the intersection of SR 542/Mount Baker Highway and the eastern leg of SR 9 to improve safety and reduce severe crashes.

Why is WSDOT building a roundabout?
Following community feedback and speed and crash analysis, WSDOT engineers determined a roundabout will be the most effective way to improve safety at this intersection. This roundabout will keep traffic moving and reduce severe crashes. The roundabout will lower the speed of travelers on SR 542 allowing SR 9 drivers to safely enter the intersection and turn left on SR 542.

What are the benefits of roundabouts?

  • They reduce delay and improve traffic flow. 
  • They are less expensive than a traffic signal.
  • They are able to be built in current footprints and often take up less space than other intersection improvement options.

What should travelers expect during construction?
During construction WSDOT contractor crews will have flaggers alternating travelers through this intersection around-the-clock. Contractor crews could work days and nights on this project to get it finished as quickly as possible. Travelers should plan for up to 30 minutes of delays if they need to travel through this work zone.

The End Result
This project will increase safety for Mount Baker Highway travelers by reducing:

  • The speed of east and west bound drivers to improve turning safety from SR 9 to SR 542.
  • Severe collisions.
  • The number of injury crashes, supporting Washington's strategic highway Target Zero plan.

Needs & benefits

This intersection improvement project will help move Mount Baker Highway neighbors and visitors safely and efficiently through this stretch of highway.


  • Fall 2017 - Advertise project for competitive bidding
  • Winter 2017/2018 - Award project to a contractor
  • Spring 2018 - Begin roundabout construction
  • Summer/fall 2018 - Complete construction


Financial Data for PIN 154214F
Funding Source Amount ($ in thousands)
2003 Gas Tax (Nickel Funding) $0
2005 Gas Tax (TPA) $0
Pre-Existing Funds (PEF) $1,441
CWA $0
Total $1,441


Andrea E. Petrich

Gabe Ng
project engineer