Interstate 5 Bridge plan hits another key milestone

Leaders say they’ve reached a key milestone in their quest to replace the century-old Interstate 5 Bridge.

The Interstate Bridge Replacement Program announced Tuesday that four Columbia River users likely to be impacted by the proposed replacement bridge’s 116-foot height restrictions have signed agreements worth $140 million to allow for a fixed-span bridge design.

“This is a critical milestone towards receiving a bridge clearance permit,” the program noted in a news release announcing the agreements with four river users — Advanced American, a marine contracting company; JT Marine Inc., a shipyard services business; and fabricators Greenberry Industrial and Thompson Metal Fab.

Now the Washington and Oregon departments of transportation can submit an updated report on navigation impacts to the U.S. Coast Guard, which must grant approval for the project to proceed.

The report makes the case for building a fixed-span bridge with a maximum vertical clearance of 116 feet instead of replacing the I-5 Bridge with another moveable span with 178 feet of clearance. According to leaders of the bridge replacement project, a fixed-span bridge would end the need for the bridge lifts that currently halt traffic. A fixed-span bridge would also be less costly.

“Based on past estimates without accounting for inflation, construction of a movable span bridge would cost approximately half a billion dollars more (in 2022 dollars) than a fixed-span and would cost $1 million more per year to operate and maintain,” project leaders said in the news release. “By comparison, these agreements totaling $140 million represent a more cost-effective solution. … Payments will only be made if the Coast Guard permits a fixed-span bridge and construction begins.”

Although the details of the four agreements are confidential, the updated navigation impact report submitted to the Coast Guard shows how some of the businesses might need to alter vessels to pass under the fixed-span bridge. Advanced American’s DB Millennium vessel, for instance, would need to lower its crane, boom and mast to clear the 116-foot-high bridge, which would require the company to expend additional time and effort.

According to the navigation impact report, the current I-5 Bridge replacement plan calls for the construction of two fixed-span, parallel bridges between Hayden Island in Oregon and the state Highway 14 interchange in Vancouver. The easternmost bridge would accommodate northbound traffic and bicycle and pedestrian pathways, and the other would support southbound traffic and public transit options, including TriMet’s light rail MAX trains.

The fixed-span bridge design would “continue to provide access for 99 percent of river traffic while removing the stoplight on Interstate 5 to improve safety and reliability for roadway commerce, vehicles and transit,” according to the news release.

Governors in Washington and Oregon said this week that they support the fixed-span bridge concept.

“This project is critical for Washington state,” Gov. Bob Ferguson said in a news release. “A fixed span removes the only stoplight on I-5 between Canada and Mexico, supports our economy and has broad consensus across many stakeholders. Reaching agreement between all four river users for the first time shows a clear path forward.”