Study Shows More Than 50,000 Structurally Deficient Bridges in America

A new report from the American Road & Transportation Builders Association (ARTBA) has confirmed what many have long suspected: The U.S. is full of structurally deficient bridges and no state is immune to the problem. The findings echo other findings of recent years, which suggest the possibility of a bridge infrastructure problem looming across the country.

Americans Drive Across Structurally Deficient Bridges 174 Million Times a Day

The American Road & Transportation Builders Association (ARTBA), an association that advocates for U.S. transportation design and construction, compiled the report using data found in the U.S. Department of Transportation’s 2017 National Bridge Inventory database. Perhaps the most concerning report finding was that out of the 612,677 bridges in America, 54,259—or around 8.86 percent of the country’s bridges—were rated structurally deficient. Americans drive over those bridges 175 million times a day, which works out to be more than 120,000 bridge crossings in any given minute.

What is a Structurally Deficient Bridge?

The term “structurally deficient” can be alarming, but a structurally deficient bridge is not necessarily dangerous; rather it has been either restricted to light vehicles, closed to traffic or is in need of rehabilitation. For a bridge to get the rating, its superstructure, substructure or deck must receive a four or less on a zero to nine ranking scale that deems a nine as “excellent” and a zero as “failed.” When a bridge is inspected and found to be unsafe, officials are supposed close it immediately.

Functionally obsolete bridges are those that were built with standards that no longer apply today, such as having inadequate lane widths or vertical clearances.

Receiving this structurally deficient rating, however, can be an important signal of trouble ahead, with unseen dangers, such as weakness in the construction or safety hazards, sometimes lurking. Time, traffic incidents and natural disasters can bring these issues to light and may result in a bridge collapse, which, while not a frequent occurrence, is often a tragedy with multiple lives lost.

Furthermore, issues with structurally deficient bridges and the bridge collapses they cause are a sign of problems with America’s infrastructure which raises concerns about public safety.

Key Study Findings

The ARTBA report identified more than the number of structurally deficient bridges in the U.S.; it also provided some alarming details:

  • Americans cross over structurally deficient bridges an average of 175 million times per day. This means there is a good chance most citizens have driven over one of these bridges recently or drive over one regularly.
  • Given the current pace of repair or replacement, it will be 37 years before America’s deficient bridges would be improved. Factor in the toll that those 37 years would take on the bridges, and one can see the depth of the challenge.
  • One out of every three bridges in the U.S. has documented repair needs. Despite this, the rate at which structurally deficient bridges are being improved has slowed slightly between 2016 and 2017.

Ten States with the Most Structurally Deficient Bridges in America

Every single state and the District of Columbia had multiple structurally deficient bridges, with the District of Columbia having the fewest at eight.

Iowa had the most structurally deficient bridges with 5,067, a number that equals 20.9% of Iowa’s total bridges and is a 2.0% increase from 2016. The state has had the highest number of structurally deficient bridges for the last three years and ranked second two years before that.

Rounding out the ten states with the most structurally deficient bridges were Pennsylvania, Oklahoma, Missouri, Illinois, Nebraska, Kansas, Mississippi, North Carolina, and New York. Those nine states have a total of 22,865 structurally deficient bridges between them.

The most-traveled structurally deficient bridge in America, however, is located in Jefferson County, Alabama, and was built in 1970. Drivers cross it a staggering 136,580 times each day.

Age and Maintenance – Factors in Bridge Collapses Throughout America

One of the biggest problems facing America’s bridges is how long most of them have been around. The ARTBA report determined the average age of a structurally deficient bridge in America is 67 years old (bridges that were not rated deficient averaged 40 years).

A 2013 Transportation for America report says most bridges are designed for a 50-year life before they will need “major overhaul or replacement.” Once a bridge has passed that age, the report says “it’s far more likely that a bridge will be deficient.”

One of the most notable examples of the dangers of an aging bridge is the Mississippi River Bridge collapse of August 1, 2007. The bridge, built in the 1960s, was built with undersized gusset plates, a problem that went undetected through numerous inspections and went unaddressed even after an inspector photographed the gusset plates warping due to stress. As the bridge aged and traffic over it increased, a deadly combination was created. Thirteen people died, and 145 were injured when the Mississippi River Bridge collapsed.

These aging bridges have increased risks compared to their newer counterparts, but inspections and maintenance are often lacking, and issues with a bridge may go unseen until a bridge collapse occurs.

State Officials Say Report Shouldn’t Alarm Residents

The numbers found in the ARTBA report are concerning, but state officials have spoken out against the findings, saying that they paint the problem in a more negative light than necessary.

Barbara LeBoe is a spokesperson for the Washington State Department of Transportation and told the Redmond Reporter that the list had inaccuracies, including a bridge that has not been rated deficient. LeBoe went on to emphasize that deficient bridges are not necessarily unsafe.

“We do not keep bridges open if we have concerns about their safety,” LeBoe reiterated.

Officials in South Carolina had similar comments, with South Carolina Department of Transportation bridge maintenance engineer Mark Hunter questioning the report to Fox Carolina news.

“Bridges get a lot of attention and they should but there’s a lot of erroneous information out there or a lot of times incomplete information,” Hunter said. He added that structurally deficient bridges may have small issues like cracks on the riding surface and said the state will close a bridge “extremely fast” if officials find it to be unsafe.

Unfortunately, in some cases—such as the Mississippi River Bridge—that action doesn’t come quickly enough.

By | 2018-02-26T09:10:02+00:00 February 12th, 2018|Bridge Collapse News|