Although the state has made great strides in protecting its own bridges from earthquakes, hundreds of bridges maintained by cities and counties across California remain unfixed.
A Times review of state and county records found that nearly 600 bridges and overpasses that officials identified as being at the highest risk for collapse in a major temblor have yet to be reinforced. They include several landmark spans in Los Angeles, such as the Hyperion bridge in Silver Lake and the Art Deco 6th Street bridge across the Los Angeles River downtown.
Counties and cities have struggled to find the money for the retrofitting projects, which have had to compete --not always successfully -- with more bread-and-butter projects like widening roads and fixing potholes.
"The cities have other priorities," said Pat DeChellis, deputy director of the Los Angeles County Department of Public Works. "They could use those funds for lots of other transportation purposes."
The California Department of Transportation has done much better: Of the roughly 2,200 quake-vulnerable bridges maintained by the agency, all but 11 have been retrofitted. To achieve this, the state has spent $2.4 billion since 1989, when the Loma Prieta earthquake collapsed an elevated freeway in Oakland, killing 43 people.
Local governments, however, complain that they don't have the financial resources for retrofitting, even though the spans they are responsible for carry thousands of commuters daily.
In the Southland, these include the La Cienega Boulevard bridge over Ballona Creek on the Westside, Avenue 26 over the Arroyo Seco, Imperial Highway over the San Gabriel River in Downey and Norwalk, Van Buren Boulevard over the Santa Ana River in Riverside and a MacArthur Boulevard bridge at John Wayne Airport in Orange County.
The work is expensive: Fixing the 6th Street bridge alone would cost $140 million. In 2002, the Legislature and then-Gov. Gray Davis eliminated a transportation fund that had been earmarked for the city and county bridge retrofits. Although federal money is also available for the program, Sacramento's decision meant local agencies had to come up with matching funds on their own.
Last year Congress moved to boost retrofitting efforts by reducing the level of matching funds required for all bridge projects from 20% to 11.47%, citing concerns over the deteriorating state of the nation's bridges. As a result, the amount that local agencies will have to pay is much less than it had been previously.
Some officials are eyeing Gov. Arnold Schwarzenegger's $222-billion public infrastructure bond proposal as a possible source of money. The Legislature is debating how such a windfall would be used. The issue of bridge retrofitting is not specifically mentioned in the governor's draft proposal, but some legislators are pushing it.
Even with help from the federal government, however, many local governments say they can't come up with the matching funds.
At a time when traffic congestion is worse than ever, officials say it can be politically difficult to put seismic retrofitting ahead of road repair and improvements and mass transit lines.
"It's an ongoing sore point for the last 10 years," said Stephen Maller, deputy director of the California Transportation Commission. "These bridges have not been a top priority for the local agencies."
After Loma Prieta, the state worked with local agencies to identify bridges in need of seismic upgrades.
John Koo, bridge group manager for L.A.'s Bureau of Engineering, said he spends "a good deal of time" trying to educate Metropolitan Transportation Authority officials and others who hold the purse strings to allocate more money for retrofitting. "I am concerned that MTA does not share the same higher priorities for seismic retrofitting of bridges as we do in the city of L.A.," he said.
Koo said the city has 27 bridges identified by the state as most in need of seismic upgrades.
But in the absence of funds from either the MTA or the state, he said, the city cannot pay for all the projects.
Local officials complain that even when money is secured, it can take years of studies and surmounting of regulatory hurdles to do the work.
"We know what needs to be done," said Lloyd Dalton, design engineer for Newport Beach, which has four bridges yet to be retrofitted. "It's very frustrating."
In San Diego, efforts to fix several historic bridges have met with opposition from community groups that worry about aesthetics. The city government is negotiating with neighborhood groups over the fate of the Georgia Street bridge, an arched span built in 1914 for the Pan American Exposition. Many of the buildings in Balboa Park were also created for the expo.
"The first time the engineers went out and told the community group about the bridge, they said it needed to come down," said Patti Boekamp, director of engineering and capital projects for San Diego. "The community became completely unglued."
Fred Turner, staff structural engineer for the California Seismic Safety Commission, said the risks to the economy as well as human life are too great to put off such work any longer.
"These are essential facilities that our economy rests on," he said. "It's really unfortunate that we haven't found ways to retrofit them."
Local governments aren't alone in their struggles to retrofit at-risk bridges.
The state Department of Water Resources, which operates the California Aqueduct and owns 24 of the bridges, hopes to finish evaluating the spans this year, start design work in 2007 and complete construction by 2008, according to Principal Engineer Richard Sanchez.
Sanchez said he does not know why it took the department so long to begin looking at the bridges but that he hopes to begin retrofitting them by 2008.
The work is important, he said, because if one or more of the bridges collapsed in an earthquake, traffic would be snarled and debris could fall into the water supply.
But even with that effort underway, seismic experts fear that many high-risk bridges are years -- or decades -- away from being fixed.
"We started these programs in 1989 with the Loma Prieta earthquake, and then we had another wake-up call in 1994 with the Northridge earthquake. And now, another  years later, it's still not done," said Frieder Seible, chairman of Caltrans' seismic safety advisory board and dean of the engineering school at UC San Diego.
"Even if it's one bridge that falls," he said, "it will be one too many -- especially if it's you or me or our family on that bridge."
Bridges at risk Here are some spans that officials have concluded have the greatest risk of failing in the event of a major earthquake.
Los Angeles County
* Fletcher Drive at the Los Angeles River in Los Angeles
* La Cienega Boulevard at Ballona Creek in Los Angeles
* Riverside Drive at the Tujunga Wash in Valley Village
* Avenue 28 at the Arroyo Seco in Los Angeles
* 6th Street at the Los Angeles River in Los Angeles
* Hyperion Avenue at Glendale Boulevard and Riverside Drive in Los Angeles
* Imperial Highway at the San Gabriel River on the Downey-Norwalk border
* Van Buren Boulevard at the Santa Ana River in the Santa Ana River Wildlife Area
* River Road at the Santa Ana River west of Norco
* Park Avenue at Grand Canal in Newport Beach
* Jamboree Road at San Diego Creek in Newport Beach
* McFadden Avenue at the Santa Ana River in Santa Ana
* Fairview Street at the Santa Ana River in Santa Ana