March 30, 2026

Core projects emerge as costs jump on interstate bridge rebuild

Photo by Cacophony via Wikipedia [enlarge]

The first span of the aging Columbia River Interstate Bridge opened in 1917.

Updated cost estimates mean the Interstate 5 Portland to Vancouver bridge replacement project will likely move forward initially with what state officials are calling a “core set” of projects, namely rebuilding the bridge (with light rail atop it) and connecting it to the interstate. Other work, including planned improvements along a 5-mile corridor of I-5, would take a back burner.

The updated cost estimate clocks the replacement project as it had been planned, including the corridor improvements at around $14.4 billion, leapfrogging 2022's $6 billion estimate and the $5.5 million in state and federal money committed for the program.

RISK, INFLATION JUMPS

The Interstate Bridge Replacement (IBR) Program, made up of multiple state and local transportation departments in Washington and Oregon, released the updated estimate for the full set of projects on March 17, saying the price tag could range from $13.5 billion to $15.2 billion, with a likely cost of $14.4 billion.

The updated figure estimates a base cost of $7.8 billion and calculates a $2.4 billion escalation for inflation, and a $4.2 billion risk estimate. That second number is a calculation of today's uncertainties that people in the construction industry know too well, including schedule delays, tariffs, design changes, workforce issues and permitting.

Nearly half — 45% — of the updated cost estimate is due to the updated calculation of risk and anticipated inflation.

The 2022 estimate also assumed project construction would be done in larger construction packages completed at the same time, but the updated estimate calculates splitting the program over two dozen construction contracts in response to industry feedback.

CORE PROJECTS

The IBR Program wants to move forward with construction of the bridge itself using the money they have in hand.

In an executive steering group presentation posted online, they identified a core set of projects for priority completion, including constructing the bridge, removing the existing span, connecting the bridge with I-5, and extending light rail over the bridge (that would connect to Vancouver in Clark County).

The RFQ to rebuild the bridge would go out in the second quarter of this year, with construction targeting a 2028 start and an opening six to seven years later. Tolling on the existing span is slated to start in 2027.

Light-rail transit would target a 2036 opening, and planners are pursuing more federal funding to fully bring that project online.

The 5-mile corridor updates on the interstate would target a 2045 completion, also requiring additional funding.

MOVING FORWARD

Washington Gov. Bob Ferguson and Oregon Gov. Tina Kotek both emphasized their shared commitment to getting started ASAP rebuilding the 109-year-old bridge and the other core projects.

“The bridge must, and will be replaced,” Ferguson said in a March 17 statement. “Delaying a major project has never made costs go down. We've achieved important progress in the past year, and we will continue to move forward by focusing on the core mission of replacing the bridge.”

The United States Coast Guard gave approval in January to a fixed-span design for the long-awaited replacement, which allows the work to proceed hundreds of millions of dollars lighter than with a movable span. But those cost savings are included.

The new plan has a few more hoops to jump before it can go out for bid. The IBR report's updated schedule anticipates federal approval of the final EIS in the second quarter of this year, and they also will need to complete an initial financial plan, along with other calculations.

“Programs of this size and complexity are typically constructed in phases,” IBR Interim Program Administrator Carley Francis said in a statement. “Starting construction on a new span across the Columbia is the first step toward delivering the full program.”

The program plans to award the contract to build the bridge next year.

Related Stories:

• Fixed-span design approval a boon for new I-5 bridge over Columbia  01-21-2026