The City of Denver has more than 640 bridges and almost 14% of those used by vehicles are deemed “structurally deficient,” according to the Department of Transportation and Infrastructure.

DOTI officials say more funding is needed to keep up with repairs to extend the serviceable life of the structures, preventing even more expensive repairs in the future.

With an average age of 38 years, city bridges are growing weary and DOTI officials say they are in a race against time to maintain repairs and the preservation work needed to prevent the structures from dropping into “poor” or “structurally deficient” categories.

“Once a bridge reaches that poor rating, you really can’t get it back,” DOTI Engineer and Manager Brad Chamberlin told members of the city’s South Platte River Committee on Wednesday. “So, you really have to look for that replacement as the option.”

In the 1940s, Denver had 53 bridges.

The growth in the number of bridges has been primarily driven by DOTI and Denver Parks and Recreation, the two largest agency owners.

“As a driver, driving on a bridge structure, you’re looking most of the time at asphalt and it looks reasonably well placed,” Chamberlin told committee members. “But I think the thing that a lot of people miss is it takes going underneath the infrastructure to really understand how it’s doing structurally.”

DOTI officials told the committee a report card on the nation’s infrastructure published by the American Society of Civil Engineers gave the city’s bridges an overall score of D minus, compared to Minneapolis and Austin which received A and A minus, respectively.

Kevin Longley of the American Society of Civil Engineers told The Denver Gazette that his organization has never “issued category grades or done Report Cards for individual cities like Denver or Austin. We do statewide Report Cards in addition to the national.”

Funding for most of the city’s bridges comes from a combination of capital improvement money and bonds.

But as bridges age, Chamberlin said, repair costs to keep them serviceable climb.

DOTI officials note they need to fill a $22 million funding gap to prevent bridges from further decay.

The city has even launched a new citywide bridge program webpage — denvergov.org/bridges — where residents can review bridge conditions on a dashboard and check for closures. 

Measures such as restricting vehicle weight can help stretch a bridge’s life, but is not optimal.

Among the bridges in most critical need of repairs, according to DOTI, are 6th Avenue and Lincoln Street over Cherry Creek, Smith Road and Sandown Road over Quebec Street, and Quebec Street over Airlawn Road.

Some city funding has been dedicated to assist with design, but DOTI officials note the total price tag is too costly to fund using capital improvement money alone.

In February, Denver Mayor Mike Johnston announced plans for a new general obligation bond that could help fund bridge repairs if the measure makes it on the November ballot.

Less than 60 days later, city finance officials warned of flat revenue citing city expenditures outpacing revenue.

In late May, Johnston announced a $250 million budget deficit over 2025 and 2026 requiring furloughs and deep cuts in spending.

This story was updated to include comments from the American Society of Civil Engineers.