EVERETT — A busy bridge in downtown Everett is so corroded underneath that city officials are trying to keep weight off it and prevent cars from parking on the shoulders.

Every day, about 30,000 cars, trucks and buses drive over the span on Broadway between Hewitt Avenue and California Street, just north of Comcast Arena at the Everett Events Center.

The bridge needs to be replaced, but the city doesn’t have the money yet.

The city installed weight restriction signs and put up barricades on a dozen parking spaces across the bridge last month. But not everyone is aware of the new rules.

As many as seven semi trucks cross the bridge each day bringing plywood and other wood products to Martin Lumber and Hardware, said Todd Nelson, who runs the lumberyard’s warehouse.

“We just learned about it yesterday,” Nelson said Wednesday afternoon over the din of a forklift. “I need to figure out where to tell the truck drivers to come in.”

Initially, the city prohibited vehicles weighing more than 5 tons from crossing in the outside lanes of the bridge. On Thursday, the city changed the weight restrictions to allow heavier vehicles to cross, depending the number of axles.

By imposing weight restrictions, the city is using an abundance of caution, Everett traffic engineer Ryan Sass said.

“If we think it’s an immediate danger, we’ll take appropriate action including closing the bridge, perish the thought,” Sass said.

Because the 88-year-old, four-lane railroad overpass is close to buildings and on a crest, many drivers don’t even realize they’re crossing a bridge.

For years, Everett’s bridges were inspected by a lone building official, not a licensed structural engineer. In May, the city hired TranTech Engineering, a Bellevue engineering firm, to inspect bridges and tunnels.

This is the first of more than three dozen bridge, culvert and tunnel inspections the company will do for the city.

The bridge passed previous visual inspections and was not on a list for replacement.

The collapse of the Interstate 35W bridge in Minneapolis, which killed 13 people and injured another 100, last August focused Everett’s attention, along with that of cities across the country, on bridge safety.

A bridge has never collapsed in Snohomish or Island counties, according to state records, although at least 70 bridges across Washington since 1923 have failed — most of them washed out in floods.

Standing to the side of the trash-strewn railroad tracks under the bridge, Sass pointed to rust and corrosion on exposed steel structural supports below the span’s walkway. He said it’s the last remaining railroad overpass of its type in the city.

After finding widespread corrosion, Sass ordered more in-depth inspections of steel beams that are encased in concrete. He said he was surprised that the problems weren’t pointed out during the last full inspection.

“Frankly, we were a little puzzled why the structural sufficiency rating was as high as it was,” Sass said.

During the last full inspection in 2002, the bridge had been given a structural sufficiency rating of 63.55, under Federal Highway Administration guidelines. The latest report gives the bridge a rating of 24.19.

New bridges normally have a sufficiency rating of 100. Bridges with a rating less than 80 are eligible for state rehabilitation money; those rated less than 50 are eligible for replacement funding.

The lower safety rating prompted the city to apply with the state for bridge replacement funding.

The city needs an estimated $5 million to replace the bridge, not including labor and design costs, Sass said.

The state Department of Transportation has a pot of $30 million for replacement projects across the state this year.

Grant Griffin, a state transportation department bridge engineer, said this year Washington cities and counties are seeking funding on 40 bridge projects, representing more than $100 million in repair and design.

A decision on funding is expected by January. If funding is identified, Sass said the bridge could be replaced as early as 2010. Any work will mean detours and closed lanes on Broadway.

There’s also a possibility the bridge could be rehabilitated, a less-costly project.

“For its age, I think it’s serving well,” he said. “The question is, ‘Are you money ahead by completely replacing it or doing some type of repair?’”

Charlie Shong, a handyman who works on downtown properties near the bridge, said he thinks the new weight limits will take time for people to get used to.

“I’ve seen trucks with bulldozers in the right lane even after the signs went up,” he said.

Reporter David Chircop: 425-339-3429 or dchircop@heraldnet.com.