For the first time since 2005, highway engineers are optimistic about reducing the number of structurally deficient and functionally obsolete bridges. The information comes from an annual survey of highway professionals in 50 state Departments of Transportation and the District of Columbia conducted by Better Roads magazine and sponsored by Contech Bridge Solutions, Inc.
The study, which provides the most current data available on bridge conditions, shows that increased funding, initiated after the I-35 bridge collapse in Minnesota, is finally working its way into the system. More than 60 percent of respondents felt that they would be able to reduce the number of functionally obsolete and structurally deficient bridges in the next year, compared to just 40 percent in 2007.
Based on this response, bridge conditions should improve in the coming year. "The lagtime is caused by major projects that can take from five to seven years to complete," says Kirk Landers, editorial director for Better Roads. Across the nation, an additional 602 bridges were added to the list of nearly 145,000 structurally deficient/functionally obsolete bridges in 2008.
Despite their optimism, funding remains the most critical concern for highway managers. "Increases for bridge construction are coming at the expense of pavement construction and maintenance," Landers warns. "Compounding the problem, people are also driving less, reducing the gas tax revenues that highway departments depend on to fund construction and maintenance."
"Environmental restrictions are also driving up costs and delaying projects," says Tina Grady Barbaccia, executive editor for Better Roads. More than 72 percent of highway managers report that environmental restrictions are causing problems. "Limitations on construction dates and bureaucratic red tape can delay or even stop projects," Barbaccia says.
"We're seeing more and more counties and cities struggling with increasingly tight budgets, says Tom Slabe, president of CONTECH Bridge & Wall Solutions. "Speed of construction and cost effectiveness are key in keeping the nation's transportation infrastructure sound and safe. Because of these needs, we have seen a significant growth in the use of prefabricated bridge systems."
Structurally Deficient vs. Obsolete
The study provides further insight into the decaying bridge inventory by breaking out structurally deficient bridges from those that are functionally obsolete.
Structurally deficient bridges are considered more serious, since they have structural problems that require limiting weight or more frequent inspections. Some must be closed. About 56 percent of the substandard bridges fall into this category, compared to 44 percent, which are functionally obsolete.
Functionally obsolete bridges may be in good condition, but don't meet the needs of current traffic. Responding agencies use a standard sufficiency rating system developed by the Federal Highway Administration, to rate each bridge. Federal law mandates that all bridges must be inspected every two years.
The worst fifty-six percent of the bridges in the District of Columbia are structurally deficient/functionally obsolete. Other states with the worst bridge conditions include:
- Rhode Island (53 percent)
- Kentucky (42 percent)
- Hawaii (39 percent)
- New York, West Virginia (37 percent)
- Massachusetts, Vermont, Connecticut (36 percent)
- North Carolina, New Hampshire (31 percent)
- Missouri, Louisiana, and Oklahoma (30 percent)
The states with the lowest percentage of structurally deficient/functionally obsolete bridges include: Arizona (10 percent); Nevada (11 percent); Wyoming (12 percent); Minnesota (13 percent); Colorado, Texas, Utah (14 percent); Wisconsin (15 percent); and New Mexico (17 percent).
Only four states were able to reduce their deficient bridge population by more than one percentage point over the past year: Maine, Montana, North Dakota, and Utah (-2 percent).
The complete bridge inventory appears in the November 2008 issue of Better Roads and at http://obr.gcnpublishing.com/articles/bridgeinv08.htm.
For a summary of bridge conditions in your state visit: http://obr.gcnpublishing.com/articles/downloads/StateByStateSummary08.pdf.