Burlington Northern Overpass Project

Burlington Northern Overpass Project

Project Number: ES50510-8 Federal Aid #BRS-M291(006)

Remember: BUSINESSES ARE OPEN: Access to businesses available just north of Cook Road.

Construction Updates | Photo Gallery
June 11, 2017

  • Crews are drilling more than 80 feet down to construct bridge piers that will support the new span
  • Demolition work wrapped up at the end of May 2017
  • Local businesses on Old Highway 99 are open, and access is available just north of Cook Road
  • VIDEO: Watch overpass demolition on Facebook (no account required)
  • Road closure began Monday, May 1
  • Drivers can expect delays along Old Highway 99, Cook Road, and Bow Hill Road

Burlington Northern Overpass
Skagit County and its construction contractor will replace the current timber Burlington Northern Overpass near Cook Road on Old Highway 99 N with a new concrete overpass. Old Highway 99 N will be closed north of Cook Road during construction; drivers will use I-5 to detour around the work area. The new overpass is expected to open in spring 2018.

Project Timeline

  • September 2016 - Design complete
  • November 2016 - Open construction bids
  • December 2016 - Award/execute construction contract
  • January 2017 Contract awarded to Cascade Bridge LLC
  • April 2017 - Begin construction
  • May 2017 – Begin demolition

The Burlington Northern Overpass is a timber and steel overpass located on Old Highway 99, three miles north of Burlington and about a quarter-mile north of Cook Road. The overpass was built in 1936 by the State Department of Highways and transferred to Skagit County in the 1960s. Due to its age and the deterioration of the timber and steel, Public Works crews have performed a series of temporary repairs to keep it open to traffic.

The Burlington Northern Overpass is a vital part of both the County and state transportation system. We recognize the importance of maintaining this arterial for the local freight community and for commuters. The existing structure is both structurally deficient and functionally obsolete, with a National Bridge Inventory System (NBIS) sufficiency rating 3 out of 100, which put this bridge as one of the top 5 worst rated bridges within Washington State. The Burlington Northern Overpass carries approximately 6,000 vehicles per day, 15 percent of which is truck and freight traffic. Replacing the bridge will ensure that this route will continue to provide reliable service for years to come

Project Benefits
Construction crews will replace the existing 1,183-foot-long timber trestle bridge with a new prestressed concrete and steel span. The new bridge will be wider, and include structural earth walls, curb and gutter, sidewalks, and a stormwater system. The wider bridge will allow more room for bicycles and pedestrians, and will reduce congestion for drivers by providing more vehicle capacity.

County Funding Partners/Sources

  • Bridge Replacement Advisory Committee (BRAC)
    • Highway Bridge Program (HBP):                              


  • Legislative Funds (State)
    • Connecting Washington:                                            

$  2,000,000

  • Freight Mobility Strategic Investment Board (FMSIB)            
$  2,000,000
  • Economic Development Fund
    • Demolition                                                                  
$     500.000
  • Total Funds Received:                                                          

For additional information about this project, please contact Bronlea Mishler at 360-416-1309 or bronleam@co.skagit.wa.us. Look for project updates on social media: #SkagitBNOP


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