Aug. 1, 2008 -- Last Saturday afternoon, Johnny Do was driving to a music festival with his wife and two children when a 1,200-pound chunk of concrete dropped from a bridge in the Minneapolis area and crashed onto the Interstate just feet from the family's minivan.
Do, who saw the concrete crush a car in front of him and smash into hundreds of pieces, was still savoring his good luck as he told ABC affiliate KSTP, "Seconds later, I would [have] hit that piece."
The bridge, located just eight miles from the infamous Interstate 35W bridge that collapsed a year ago today, killing 13 people in the deadliest such disaster in a generation, was inspected last August by state officials,who found it to be deteriorating but safe.
Since last year's fatal collapse, states and counties have spent billions of dollars on inspections and repairs. But a number of the country's most vulnerable bridges have yet to be fixed or replaced, according to an analysis by ABCNews.com.
"People are talking more about bridge safety," said William Ibbs, a professor of civil engineering at the University of California-Berkeley. The Minneapolis collapse "raised the issue higher on radar screens, but show me the money."
Some of that money is beginning to emerge, with six states spending an extra $8.3 billion for bridge and road spending.
Last week, another $1 billion was approved by the U.S. House of Representatives for bridge work, though President Bush has threatened to veto the expenditure.
But with many of the nation's highly trafficked, aging bridges still in need of updates, the repair process has been too slow, in the eyes of some.
"I still don't see the money coming for repairs and for infrastructure improvements, in general," Ibbs said. "Bridges are continuing to age and there is more traffic, with heavier vehicles on them over time and changing weather patterns, which make for a dangerous freeze-thaw cycle."
Some May Need Replacement
Twenty heavily trafficked bridges across the country scored a lower structural integrity rating than the I-35W bridge before its collapse and "may need to be replaced," according to a report last year by ABC News's Brian Ross.
Over the past year, some of those bridges underwent repair work. Others were subject to routine maintenance. Others are slated to be replaced.
At least one bridge actually received a worse rating in 2007 than it got in 2006, despite efforts to repair it.
Colorado's South Platte Bridge over I-25ML, which rated a 36 percent in 2006, dropped to 24.5 percent in 2007, despite the fact that repair work was done to the steel columns and steel plates in December 2006, according to Mindy Crane, spokeswoman for the Colorado Department of Transportation.
The sufficiency rating, which calculates everything from the condition of a bridge's deck and abutments to its weight limits and roadway width, indicates a bridge's sufficiency to remain in service, with 100 percent representing an entirely sufficient bridge and zero percent representing an entirely deficient bridge.
No additional work has been done on South Platte bridge since it received that rating. State bridge engineer Mark Leonard said the lowered rating was due to the decision to lower the load capacity of the structure and emphasized that the bridge is "structurally sound."
The eight-mile Bay Bridge, which links San Francisco and Oakland, Calif., and received a 32.1 percent rating, is scheduled to be replaced in 2013 by a new one that will feature the world's largest self-anchored suspension bridge -- a $13 billion job that is billed as the largest public works effort in California history.
New York's Joramelon Bridge received a 34 percent rating, but "there are no open flags" for serious problems such as corroded steel or loose concrete, according to Ted Timbers, deputy press secretary of the New York City Department of Transportation.
"Nothing needs to be repaired on this bridge at this time," he said.
Virginia's Boundary Channel Bridge over the Shirley Memorial Highway, which is rated a 42.5 percent, is due for an "investigative study" this fall that will involve testing the internal condition of the concrete to determine if it needs any rehabilitation, according to Joan Morris, spokeswoman for the state's department of transportation.
"It's not a dangerous bridge -- it's just old," says Morris, stressing that the bridge received a low rating because some of its design features are dated.
Similarly, the Bourne Bridge in Massachusetts, which was built in 1935, received the low rating largely due to its age, having undergone major rehabilitation in 2001, according to Cape Cod Canal manager Frank Fedele.
"We have started doing interim 12-month inspections," he said. "We would like to do something bigger and better, but we've got what we've got. But when you take the time and effort we put into inspections, I'm very satisfied that our bridge is safe."
In California's Caltrans district 7, which covers Los Angeles and Ventura counties and where two bridges -- Metrolink over I-710 and Noakes Street Bridge over I-710 -- made the list, all state bridges have been retrofitted except one, which is scheduled for replacement, said Dave White from the state's DOT.
Across the country, two-thirds of the most heavily-trafficked problem bridges in each state have not received any work beyond regular maintenance since last year's I-35W bridge collapse, according to an Associated Press review.
Only 12 percent of those bridges had their structural defects fixed and 24 percent had received a partial improvement such as short-term repair work.
None of the 1,020 bridges reviewed by the AP were in immediate danger of collapse, according to state engineers and officials.
Replacements at the County Level
Smaller counties across the country, some of which have high numbers of deteriorating small bridges, are taking steps to fix or replace them.
Of the 155 bridges in Attala County, Miss., 76 are rated for either major rehabilitation or total replacement, according to county engineer Christian Gardner.
"We did have one bridge that fell in under traffic some years ago," he said. "A tractor going across fell to the bottom of the creek, but there were only minor cuts and bruises."
The county was rated the one with the second-highest number of failed, imminent, critical and serious bridges, according to an analysis of federal statistics by geo-spatial engineer Sean Gorman.
The county with the third-highest number, Pennsylvania's Allegheny County, also has an ambitious program to inspect and maintain its 500 bridges, recently receiving an additional $1.1 million for bridge repairs.
County officials examined five steel deck-truss bridges -- the collapsed I-35W bridge's design -- in the last year. One is due for replacement and three will be rehabilitated, including one bridge that will receive fiber-optic and strain gauges that measure the bending and stretching of critical parts of the structure.
"We have a lot of old bridges that we have -- and we have to keep an eye on them," said Joe Hrabik, the deputy director of the county's public works division.
"The Minneapolis collapse was a wake-up call, and we have to make sure that we expand our resources to keep bridges operational," he added.
Federal officials insist that significant steps have been taken to improve the inspection and repair of the nation's bridges.
After the I-35W collapse last August, the Federal Highway Administration demanded that states inspect all 497 deck truss bridges in the country. The states all responded, and of the three bridges that needed some repair work, "whatever was needed to be done was done," says Nancy Singer, a spokeswoman for the Federal Highway Administration.
Engineers say that a bridge collapse remains a rare event.
"Every 30 or 40 years, these types of catastrophic collapses take place," said Henry Petroski, a professor of civil engineering at Duke University.
"Another collapse is unlikely in the near future due to all this renewed attention on their condition and safety," he said. "But there is always a danger of complacency, the more time that passes since Minneapolis."