The State of Your Bridges

Our exclusive survey of bridge conditions in the United States

By Tina Grady Barbaccia

It’s a case of good news/bad news.

Better Roads’ 2010 Annual Bridge Inventory reveals that fewer of the country’s bridges are considered structurally deficient (SD) or functionally obsolete (FO) than any time in the last five years. That’s the good news. The bad news is that the number of bridges in those classifications is still worryingly high.

The nation has 600,513 total bridges, but 23.3 percent — or 139,620 of them — are considered structurally deficient (SD) or functionally obsolete (FO). Of America’s 291,034 total interstate and state bridges, 61,149 – or 21 percent – are SD/FO. There are 309,479 total city/county/township bridges in the United States, and 78,471 — or 25.4 percent — are SD/FO.

But there are 2,278 fewer bridges than last year rated as SD or FO. Last year, out of the 597,787 total bridges surveyed, 141,898 of them — or 23.7 percent — were SD/FO. Compared to last year, there are also fewer SD/FO interstate and state bridges. In 2009, 62,504 — or 21.6 percent of the total 288,920 interstate and state bridges — were SD/FO and 79,394 — 25.7 percent — of the 308,867 city/county/township bridges were found to be SD/FO last year. [Editor’s Note: The 2009 numbers use 2008 data from Massachusetts and 2007 data from Rhode Island because updated numbers were not supplied for the 2009 Bridge Inventory.]

These are some of the findings from the Better Bridges 2010 Annual Bridge Inventory, an original research project conducted annually by Better Roads.

Where the most troubled bridges are

Although our nation’s capital has only 199 bridges, Washington, D.C., has the worst percentage of SD/FO bridges in the nation by overall percentage. Of the District’s 199 bridges, 123 — or 62 percent — are SD or FO, 7 percent more than in 2009.

The District of Columbia’s DOT (DDOT), however, says it expects to lower the rate of deficient bridges in the coming year through rehabilitation and reconstruction projects. But availability of funding remains the greatest challenge in reaching this goal, says Don Cooney, infrastructure project management administrator for the DDOT, in his survey response to Better Roads.

Rhode Island is the second worse, with 417 — 53 percent — of 789 total bridges being SD or FO. The state has 54 percent — 341 — of its 634 total interstate and state bridges in FO or SD condition — and 49 percent — 76 of 155 — of total city/county/township bridges in SD or FO condition. “We have instituted a plan that targets structurally deficient bridges,” David Fish with the Rhode Island DOT points out in his survey response.

The third ranking for combined overall FO/SD bridges is shared by Hawaii and Pennsylvania with a 38-percent rate of overall combined SD/FO bridges. Pennsylvania has a higher rate of problem city/county/township bridges — 46 percent, or 3,143 of its total 6,815 municipal bridges — than Hawaii which also has 36 percent, with 147 of its 403 bridges in SD/FO condition. However, Hawaii has more SD and FO interstate bridges, 39 percent, than Pennsylvania, which has 34 percent or 5,708 of its 16,718 total state and interstate bridges in either SD or FO condition.

But Pennsylvania DOT (PennDOT) has an Accelerated Bridge Program (ABP) that is focused on reduction of structurally deficient bridges, explains James M. Long, P.E., assistant chief bridge engineer. What’s more, “PennDOT has already implemented a design approach for 100-year bridge life to ensure durability,” Long says.

It appears the ABP has made a difference. Last year, Pennsylvania had the most combined structurally deficient and functionally obsolete bridges by state. Of its 23,562 surveyed last year, it had a combined 9,130 — or 39 percent — that were SD/FO. That figure is down 1 percent this year. Although its percentage of SD/FO city/county/township bridges hasn’t changed (46 percent), the state’s percentage of SD/FO state and interstate bridges has decreased by 2 percent from last year’s 36 percent.

The Hawaii DOT also expects to be able to lower its rate of deficient bridges in the coming year, but it will come “very slowly,” says Paul Santo, bridge design engineer for the Hawaii Department of Transportation. “We have prioritized work on these bridges through our bridge management program,” he says.

New York State records the fifth-highest percentage of combined SD/FO bridges with 37 percent of its total 17,405 bridges bearing an SD or FO rating. Breaking it down, 39 percent — 3,215 — of New York’s 8,335 total interstate bridges are SD/FO, and 36 percent — 3,230 — of the state’s 9,070 city/county/township bridges are SD/FO.

Next is a tie between Connecticut and West Virginia with 36 percent of their total bridges in SD/FO condition. West Virginia has more total bridges — 2,509 — in SD/FO condition than Connecticut, which has 1,508 rated as SD/FO. But 71 percent, or 78, of West Virginia’s 110 total city/county/township bridge are SD/FO, while only 34 percent — 424 — of Connecticut’s 1,240 total city/county/township bridges are SD/FO.