All told, the number of “structurally deficient” bridges dipped by 14 percent in the last six years. But even with the improvement, one in 10 bridges in the country is still considered structurally deficient.
Structurally deficient bridges are not necessarily unsafe but they are the ones in the most need of maintenance, rehabilitation or outright replacement based on a numerical score developed by the federal government. Such bridges must be inspected every year, because one or several of their load-carrying parts are in poor condition. Officials often divert heavy vehicles from crossing them.
“There has been a renewed focus and increased attention paid to bridges,” said Robert Victor, who heads an American Society of Civil Engineers’ group that evaluates the state of the country’s infrastructure.
The public seizes on stories of bridge failures, particularly when they involve motorists’ deaths, Victor said. That was the case in the 2007 collapse of the Minneapolis bridge carrying Interstate 35W over the Mississippi River. Thirteen people died in the collapse.
“Minneapolis grabbed people’s attention,” Victor said, much in the same way as flooding in New Orleans after Hurricane Katrina focused the country’s attention on the levee system.
King Gee, director for engineering and technical services for the American Association of State Highway and Transportation Officers, indicated the real impact of the Minneapolis bridge collapse was not on the public — because the news quickly faded — but on state engineers assessing the weaknesses of their own systems. “It caused every state to look at their own bridges,” he said.
Federal policy shifts also prompted states to better manage their inventory of bridges and roads, Gee adds. The Federal Highway Administration over the last 12 years has pressed states to make decisions on what would be the most cost-effective ways to improve the system as a whole, rather than just address individual roads or bridges. Congress codified that approach in its latest surface transportation law, called MAP-21.
The approach is easily applied to bridges and to pavement, Gee said, because states have so much data on their condition. States have been inspecting bridges since the 1960s.
The federal surface transportation law expires this fall, and federal transportation money to states may dry up even before that. If Congress does not find the money to continue or increase current funding levels, the number of troubled bridges could start climbing again, Gee said.
Another factor that could make future bridge upkeep difficult is their age. The average age of bridges in the country is 43 years old, and most of them were only built to last for 50 years
In recent years, a handful of states have accounted for most of the national improvement in reducing structurally deficient bridges. Oklahoma, Missouri, Texas, Mississippi, Pennsylvania and Ohio posted the biggest improvements in the last six years and together were responsible for 57 percent of the decrease in structurally deficient bridges nationwide.
The states started in very different situations at the time of the Minneapolis bridge collapse.
Take Pennsylvania and Texas. Pennsylvania had the highest percentage of structurally deficient bridges of any state in 2007. Despite major repair efforts, it remained in that spot through 2013. Texas, on the other hand, began with a lower percentage of structurally deficient bridges than all but four other states. By 2013, only Florida and Nevada had a smaller portion of deficient bridges.
| State | Change in S.D. Bridges | Percentage Change | 2013 S.D. Bridges | 2013 Bridges | 2007 S.D. Bridges | 2007 Bridges |
|---|---|---|---|---|---|---|
| Pennsylvania | -754 | -12.6 | 5,218 | 22,660 | 5,972 | 22,325 |
| Rhode Island | -4 | -2.3 | 167 | 766 | 171 | 748 |
| Iowa | -187 | -3.6 | 5,043 | 24,398 | 5,230 | 24,776 |
| South Dakota | -14 | -1.1 | 1,210 | 5,875 | 1,224 | 5,924 |
| Oklahoma | -1701 | -28.7 | 4,227 | 22,912 | 5,928 | 23,528 |
| Nebraska | 343 | 14.3 | 2,739 | 15,370 | 2,396 | 15,475 |
| North Dakota | -39 | -5.1 | 726 | 4,439 | 765 | 4,458 |
| Maine | 10 | 2.8 | 366 | 2,402 | 356 | 2,387 |
| New Hampshire | -45 | -11.3 | 355 | 2,438 | 400 | 2,364 |
| Wyoming | 40 | 9.9 | 443 | 3,099 | 403 | 3,030 |
| Louisiana | 39 | 2.2 | 1,827 | 13,050 | 1,788 | 13,342 |
| Missouri | -1119 | -25.0 | 3,357 | 24,350 | 4,476 | 24,071 |
| Mississippi | -834 | -26.8 | 2,274 | 17,044 | 3,108 | 17,007 |
| West Virginia | -129 | -12.0 | 944 | 7,125 | 1,073 | 7,007 |
| Hawaii | -4 | -2.7 | 144 | 1,125 | 148 | 1,117 |
| North Carolina | 27 | 1.2 | 2,308 | 18,168 | 2,281 | 17,783 |
| New York | -83 | -3.8 | 2,078 | 17,442 | 2,161 | 17,361 |
| Michigan | -459 | -26.1 | 1,298 | 11,022 | 1,757 | 10,923 |
| South Carolina | -249 | -19.2 | 1,048 | 9,275 | 1,297 | 9,221 |
| Alaska | -32 | -19.4 | 133 | 1,196 | 165 | 1,229 |
| California | -480 | -14.8 | 2,769 | 24,955 | 3,249 | 24,189 |
| Indiana | -125 | -6.0 | 1,944 | 18,953 | 2,069 | 18,494 |
| Kansas | -453 | -15.1 | 2,554 | 25,171 | 3,007 | 25,464 |
| Connecticut | 52 | 14.4 | 413 | 4,218 | 361 | 4,175 |
| Idaho | 47 | 13.1 | 406 | 4,232 | 359 | 4,104 |
| New Jersey | -133 | -17.6 | 624 | 6,566 | 757 | 6,448 |
| Massachusetts | -103 | -17.5 | 487 | 5,136 | 590 | 5,019 |
| Vermont | -284 | -53.1 | 251 | 2,731 | 535 | 2,712 |
| Kentucky | -136 | -9.9 | 1,234 | 14,116 | 1,370 | 13,639 |
| Alabama | -536 | -27.6 | 1,405 | 16,078 | 1,941 | 15,881 |
| Virginia | -28 | -2.3 | 1,186 | 13,765 | 1,214 | 13,418 |
| Illinois | -257 | -10.2 | 2,275 | 26,621 | 2,532 | 25,998 |
| Wisconsin | -110 | -8.4 | 1,198 | 14,088 | 1,308 | 13,798 |
| District of Columbia | -4 | -16.0 | 21 | 252 | 25 | 245 |
| Ohio | -708 | -24.0 | 2,242 | 27,015 | 2,950 | 27,999 |
| Minnesota | -72 | -6.2 | 1,086 | 13,137 | 1,158 | 13,067 |
| New Mexico | -109 | -26.8 | 298 | 3,935 | 407 | 3,850 |
| Montana | -113 | -23.1 | 376 | 5,126 | 489 | 4,982 |
| Arkansas | -151 | -14.6 | 880 | 12,748 | 1,031 | 12,534 |
| Delaware | 35 | 166.7 | 56 | 864 | 21 | 856 |
| Maryland | -63 | -15.9 | 333 | 5,291 | 396 | 5,128 |
| Colorado | -49 | -8.4 | 536 | 8,612 | 585 | 8,374 |
| Tennessee | -178 | -13.3 | 1,157 | 20,058 | 1,335 | 19,838 |
| Georgia | -213 | -20.3 | 835 | 14,769 | 1,048 | 14,563 |
| Oregon | -100 | -18.8 | 431 | 7,656 | 531 | 7,318 |
| Washington | -38 | -9.3 | 372 | 7,902 | 410 | 7,686 |
| Utah | -127 | -52.0 | 117 | 2,974 | 244 | 2,851 |
| Arizona | 51 | 27.3 | 238 | 7,862 | 187 | 7,387 |
| Texas | -967 | -43.0 | 1,283 | 52,561 | 2,250 | 50,272 |
| Florida | -48 | -15.6 | 259 | 12,070 | 307 | 11,664 |
| Nevada | -16 | -30.8 | 36 | 1,853 | 52 | 1,705 |
Source: U.S. Federal Highway Administration, National Bridge Inventory
Making state-to-state comparisons can be tricky, national experts warn. Sun Belt states tend to have fewer deteriorating bridges than those in the Northeast or Midwest, where the infrastructure tends to be older and the winter climate harsher on steel and concrete structures.
Since the Minneapolis bridge collapse, Oklahoma reduced the number of its structurally deficient bridges by more than 1,700. But the rallying cry for the improvement, officials there say, came before the Minneapolis tragedy.
Fourteen people died in a 2002 Oklahoma bridge collapse, when a barge collided with a bridge carrying Interstate 40 over the Arkansas River. The accident also shut down that span of the highway for two months during reconstruction, and officials had to reroute traffic to other roads.
But the 60 bridges on the two detour routes were in bad shape, too, said Terri Angier, a spokeswoman for the Oklahoma Department of Transportation. “At same time traffic was going over bridges, we were under them, fixing them up and jacking them up,” she said The state paid $15 million to replace the span of Interstate 40 that collapsed and another $15 million to fix the bridges that were used in the detours.
State funding for roads and bridge repair had stagnated since the 1980s, and the transportation agency did not have enough money to repair or sometimes even just paint bridges, Angier said. A major Oklahoma wheat grower reported that it had to send its trucks through Kansas because so many Oklahoma bridges could not handle heavy trucks. And then, in 2004, a chunk of concrete fell off a bridge 50 miles south of Oklahoma City and killed a Texas woman.
Legislators agreed to the first in a series of boosts for transportation funding in 2005. They devoted general funds, in addition to money from fuel taxes, to improving the road network. Lawmakers passed several more increases, the most recent in 2012, and largely spared the new transportation money in budget cuts this year, Angier said.
The new laws will increase Oklahoma’s annual road budget from $200 million a year in 2005 to $775 million by 2018. This year’s budget is roughly $550 million.
Angier is excited about the state’s progress. “We’re going after the Number 1 ranking in good bridges,” she said. Other states “no longer have Oklahoma to point to as worse than them.”
Federal data on the condition of bridges also show that, since the Minneapolis bridge collapse:
- Nine states saw an increase in the number of structurally deficient bridges. Those states are Nebraska, Connecticut, Arizona, Idaho, Wyoming, Louisiana, Delaware, North Carolina and Maine. But the numbers were relatively small. All together, the nine states accounted for an increase of 644 structurally deficient bridges.
- Vermont and Utah cut the biggest percentage of their bridges listed as structurally deficient. Since 2007, both states reduced that list by more than half.
- Delaware and Arizona had the highest percentage increases in the number of structurally deficient bridges, but that’s because they had so few structurally deficient bridges to begin with. In fact, in 2007 Delaware and Arizona had the lowest percentage of structurally deficient bridges of any states.
- Minnesota had 72 fewer structurally deficient bridges in 2013 than in 2007. As of last year, 8.3 percent of its bridges were structurally deficient.
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