The bridges are spread around the region.
The Post Street Bridge in downtown Spokane.
The old Interstate 90 bridge at Stateline.
The Harrison Bridge in North Idaho.
Some 2,700 bridges in Washington and Idaho have been ranked either “structurally deficient” or “functionally obsolete,” according to federal statistics – though bridges often serve for years with such designations and are not by definition unsafe for travel.
But the collapse of a freeway bridge in Minneapolis on Wednesday has focused attention on bridge safety, with some observers calling for increased attention to bridge maintenance and repair.
“What that’s really saying is we know we have issues with bridges in our country,” said David McLean, a professor of civil engineering at Washington State University. “It’s really coming down to a question of investment in our infrastructure.”
A federal estimate five years ago put the bridge repair backlog nationally at at least $55 billion.
Washington state highway officials emphasized Thursday that the state’s bridges, even those with weight limits or repair needs, are safe for drivers.
“We don’t have any unsafe bridges right now that people are traveling over,” said Jerry Lenzi, the regional administrator for the state Department of Transportation in Spokane.
The DOT oversees roughly 3,000 bridges on the state highway system around Washington, and roughly 25 percent have been judged structurally deficient, said Jugesh Kapur, the state’s bridge engineer with DOT.
Engineers said that bridges deemed structurally deficient can have a wide range of problems that require maintenance, weight limits or special attention – but which don’t mean the bridge is in imminent danger of collapse. Sometimes they’re relatively minor problems, such as missing or damaged bridge railings, they said.
“It’s not that the bridge is in imminent danger of falling down at this time, but this is how we limit the loads and extend the life of a bridge,” said Mark Serbousek, acting director of the city of Spokane’s streets department.
Jeff Stratten, spokesman for the Idaho Department of Transportation, sounded a similar note.
“A structurally deficient bridge in Idaho is a candidate for replacement or repair,” he said. “But it doesn’t necessarily indicate the bridge is a danger to the public or even needs any restrictions.”
Still, the designation is a sign of needed maintenance, and sometimes an indication that a bridge needs replacement. Seven bridges overseen by Spokane County have been assigned weight restrictions, including the old I-90 bridge at Stateline, on Appleway Road.
The county hopes to replace the bridge, built in 1939, in the next several years, and is awaiting federal funding to get started. County bridge engineer Neil Carroll said the bridge requires extra attention and concern, in part because it’s in an area with a lot of new development and in part because it has a similar design to a Harvard Road bridge that failed in Spokane County in 1992 and had to be replaced.
“I am very concerned about the old I-90 bridge,” he said.
In downtown Spokane, the Post Street Bridge has had weight restrictions for years. It may eventually be turned into a pedestrian bridge.
Federal funding for bridge projects hasn’t been forthcoming for three years, Serbousek said.
“Local agencies are really scrambling right now” to pay for bridge maintenance, he said.
The city of Spokane is in charge of inspecting 38 bridges, and several are either structurally deficient or functionally obsolete, including bridges on Sunset Highway and Freya, Serbousek said. It completed a massive repair project on the Monroe Street Bridge in 2005.
Idaho officials are in the midst of replacing the bridge just north of Harrison, Stratten said. It’s had such severe load restrictions in recent years that school buses stopped and had children walk across the bridge rather than risk it.
Under federal law, bridges must be inspected every two years, and bridges with potential problems are inspected more frequently.
Among Washington state bridges, the Alaska Way Viaduct in Seattle probably gets the most inspections, Kapur said.
Lenzi said no bridges in Eastern Washington need the kind of attention of the viaduct or a handful of other Seattle bridges.
Late Thursday, federal officials asked states to perform inspections of all bridges of a design similar to the Minnesota bridge that collapsed – a “steel-deck truss bridge.”
Kapur couldn’t say late Thursday precisely how many of those bridges Washington has, but truss bridges in general make up about 20 percent of state bridges. Others noted that most bridges in the Spokane area are concrete.
“We are a concrete society here,” Serbousek said.