A bridge where failure of one part can cause the collapse of the entire bridge or a section of it.
“A fracture critical member (FCM) is a steel member in tension, or with a tension element, whose failure would probably cause a portion of or the entire bridge to collapse.” - Federal Highway Administration
A rating on a scale up to 100 that rates the bridge’s structural condition, its usefulness and other factors.
Can mean significant load-carrying elements are in poor condition or the space underneath is extremely insufficient, causing intolerable traffic interruptions. Does not say a bridge is unsafe but typically requires significant repair to stay in use, and eventual replacement.
Out-of-date design, like an old house that’s not up to code. Not necessarily related to safety at all.
Source: American Association of State Highway and Transportation Officials
Replacing Georgia bridges
Georgia has three fracture critical bridges, all scheduled for replacement within the next five years:
- Ga. 53 over Lake Lanier, at the Forsyth and Hall county line.
Replacement starting fiscal year 2015
- Ga. 369 over Lake Lanier, Browns Bridge, in Forsyth County.
Replacement starting fiscal year 2018
- Ga. 47 over Strom Thurmond/Clarks Hill Lake in Lincoln County.
Replacement starting fiscal year 2014
The Spring Street Bridge in downtown Atlanta carries thousands of drivers to some of the biggest entertainment events in Georgia. It also has deteriorating concrete, “cracking,” “leaching,” a steel support post “loose and relatively free to move” and a sufficiency rating of three out of 100, according to inspection reports.
Officials assure the public the bridge is “absolutely safe” as it awaits reconstruction within the year, though heavier vehicles are prohibited.
The collapse of the I-5 bridge in Washington state Thursday has brought renewed attention to bridge safety nationwide, just as happened with the fatal 2007 collapse of an I-35 bridge in Minneapolis-St. Paul. Since then, Georgia has made progress in dealing with its neediest bridges, and officials say that no Georgia bridge would be open to traffic if it were unsafe.
But hundreds of Georgia bridges remain structurally deficient, meaning it may be safe to drive but something important is wrong, such as significant load-carrying parts in poor condition.
Out of Georgia’s 14,700 bridges, 878 were listed in 2012 as structurally deficient.
And as bridges such as the nearly century-old one on Spring Street show, funding shortfalls and bureaucracy are still a drag on making fixes.
After decades of wrangling between Atlanta and the state over who would fund the project and when, the Spring Street Bridge is scheduled for rebuilding within the year. In the meantime, “trucks and buses are not allowed on the existing structure,” according to a DOT online document.
In one hour Friday, however, a reporter observed two garbage trucks, three MARTA buses, three apparent cement trucks and some delivery trucks cross the bridge.
In response to AJC questions, MARTA said in a statement that it would reroute the buses to Peachtree and Marietta Streets to avoid the Spring Street Bridge. The agency had temporarily run the two routes on Spring due to construction on Forsyth Street.
It was unclear how heavy the trucks and buses were. In interviews, city and state officials said that is the real issue.
One question concerns the warning signs saying who can’t drive on the bridge.
According to the city and DOT there are two signs.
Both are posted, but a reporter and a photographer at the intersection where the bridge starts saw one, placed at the entrance of a different roadway: a closed entrance ramp at the Martin Luther King, Jr. federal building that is across from the bridge.
That sign, and another on Martin Luther King, Jr. Street, say only “Weight Limit” and list weight amounts — not where the weight limit applies.
The city stressed that it was in compliance with the Georgia DOT, which has the authority over the matter. DOT confirms those signs are proper posting for the bridge.
A local office worker looking at one of the signs Friday said they did not do the job. “You would have no way of knowing” it’s a restriction for the bridge, said Elaine Thompson, 47, standing at the intersection at lunchtime. “They probably can’t even see them.”
Questioned about the signs late Friday afternoon, a spokesman for the city, Reese McCranie, said “the city will take the necessary steps to maintain clear signage,” and “if a change is needed, we will make the necessary change.”
He also stressed that the bridge was safe and had been “double and triple checked” by state and city inspectors.
The bridge, built in the early 1920s, spans the “Gulch” area downtown over CSX train tracks, and ferries cars to parking lots for CNN Center, Philips Arena, the Georgia Dome and other venues. It is owned by the city of Atlanta, but the state Department of Transportation is largely funding the $14 million project, according to DOT.
Neither the state nor the city has enough money to fix all their deficient structures, especially as the interstates age. The federal gas tax, the major source of money for road and bridge funding in Georgia, doesn’t rise with inflation.
DOT makes do every year, parceling out a fraction to bridges, to other safety projects, and to congestion relief.
All the same, the state has made strides in dealing with the worst of the worst. In 2008, 59 Georgia bridges were listed with a sufficiency rating of 10 or less. By 2012, that fell to 45. Many of those may be small, out-of-the-way bridges that are not managed by the state Department of Transportation but by towns or counties.
“We have improved our bridge inspections, bought new equipment, we have invested and put an effort into doing the best we can with what we have,” said DOT spokeswoman Jill Goldberg.
An AJC analysis of national bridge data found that as of 2012, no Georgia interstate highway bridge had a sufficiency rating below 40. However, a few were below 50, the mark where the federal government pays for rebuilding.
The Washington I-5 bridge was above 50, showing that ratings aren’t everything.
Also, the Washington and Minneapolis bridges were not like the Spring Street bridge, or like most Georgia bridges. They were “fracture critical” steel truss bridges, meaning that if one part fails, the whole bridge could fail. Georgia has three fracture critical bridges, according to DOT, and all are scheduled for replacement within five years. On the two out-of-state bridges that failed, there were apparently other factors: an alleged oversize load that knocked out a steel girder of the Washington structure, and overloading of the Minneapolis structure.
DOT does not designate the Spring Street bridge as fracture critical. However, an inspection report for that bridge named two concrete columns and their beam system as “the fracture critical section for the superstructure and connection to the substructure.”
The state DOT has made the Spring Street bridge a priority, but said in recent years that it could not rebuild the bridge until it finished a bridge on Mitchell Street. However, the Mitchell Street bridge has been complete and open to traffic since last August. The Spring Street bridge is not expected to go out to bid until October, and then may not see construction until spring of 2014, a year and a half after the Mitchell bridge reopened.
Goldberg said many things may still be required for the project now, such as buying land or finishing design, though the specific reason was not immediately available.
Drand Dixon, 55, works downtown and doesn’t care what the reason is. The project has waited decades, he has driven over the bridge in those years, and he would like it fixed sooner rather than later.
“I don’t think it’s a good thing to push something off that’s so serious,” he said.