Ongoing Fieldwork Beginning in Fall 2026

November to February: Geotechnical Borings 

In November, we’ll begin geotechnical borings in the main stem of the Columbia River to help guide design of support structures for the new bridge. You can expect to see crews working from barges to drill borings in the river in order to collect soil samples. The current plan is to complete 16 borings between November and February. 

There won’t be any traffic impacts from the work. On the Columbia River, at least two of three river navigation channels will remain open at all times. 

What fieldwork can you expect? 

Field investigations provide important information about environmental conditions, existing infrastructure and site characteristics. This information helps engineers advance design and prepare for future construction activities.

Field crews may perform activities such as:

• Land and water surveys
• Environmental investigations
• Utility and site investigations
• Geotechnical and river studies

When and where will work occur? 

Ongoing fieldwork to prepare for construction starting in 2028 is scheduled to begin in fall 2026. The work will likely be performed during the day, Monday – Friday. However, there may be occasional work performed on the weekend. 

Fieldwork may be visible:

• Along I-5
• Along SR-14
• On the north shore of Hayden Island
• In the Columbia River near the existing Interstate Bridge
• Along the southwest Washington shoreline

What are the traffic impacts?  

The majority of fieldwork currently planned is not anticipated to take place within travel lanes. Shoulder closures are possible, but significant traffic impacts are not currently anticipated. If any lane or ramp closures are determined to be necessary, they would be communicated in advance.

If you have additional questions about fieldwork contact us at info@interstatebridge.org.