The Washington state bridge collapse was a reminder to U.S. drivers about the dangers posed by our nation’s aging infrastructure.

The United States currently has the largest road network of any country on Earth, with more than 4 million miles of roads and streets. Although the construction of this elaborate highway system is certainly a national accomplishment, maintaining an aging transportation network is a challenge in which we’ve fallen short, as a bridge collapse last week loudly reminded the nation.

Last week, a truck collided with a bridge girder on Interstate 5 in Washington, leading to a bridge collapse over the Skagit River near Mount Vernon. Although there were luckily no fatalities from the collapse, three people sustained injuries that required a hospital stay, and the total bill for the damages is expected to reach about $15 million.

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The 18-wheeler may have hastened the demise of this particular bridge, but there’s no doubt its age played a role in its collapse. It had even been rated “functionally obsolete,” although state officials asserted it was safe for drivers, according to CNN. The I-5 bridge in near Mount Vernon, Wash., isn’t unique for its age. Consider this: The average age for bridges in the United States was 42 years in 2011, and many have already exceeded their expected 50-year lifespan, according to a report by Transportation for America.

In 2012, the Federal Highway Administration reported that 11 percent the 607,000 bridges in the United States were structurally deficient. These bridges would be monitored and inspected by transportation officials, but were still deemed safe enough for drivers.

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Of the bridges deemed to be structurally deficient, here are some of the standouts:

  • Harlan Springs Road Bridge, West Virginia: Despite holes in the road and rust in the railings, this bridge continues to be in service even though its more than 100 years old and been reduced to a single lane.

  • Lake Shore Drive, Illinois: Lake Shore Drive offers a scenic view of Chicago along the shores of Lake Michigan. But since this bridge was constructed in 1915, it has been slowly crumbling under the weight of the thousands of vehicles that ride its pavement everyday.

  • Raritan River Bridge, New Jersey: Constructed in 1929, this bridge still sees more than 200,000 commuters pass over its crumbling concrete and aged steel on a daily basis.

  • Oakland Bay Bridge, California: Lightning hopefully won’t strike twice with the Oakland Bay Bridge, which saw a section collapse in 1989. It wasn’t actually lightning that caused the collapse, but instead a magnitude-6.9 earthquake.

  • Verrazano Bridge, New York: Although it has just barely reached its expected lifespan, the Verrazano Bridge, built in 1964, is not only the state’s most dangerous bridge; it’s also the busiest.

  • Huey P. Long Bridge, Louisiana: Huey P. Long lives up to its nickname, “Old Bridge,” having been constructed in 1940 and living up to every one of its 73 years. If it wasn’t bad enough that the narrow lanes on this bridge have been responsible for all sorts of

If those bridges don’t seem anywhere along your daily route, consider that the conditions of these structures is by no means a rare occurrence. According to the 2011 Transportation for America report, the following states have the highest percentages of structurally deficient bridges out of the total bridges in the state:

  • Pennsylvania: 26.5 percent

  • Oklahoma: 22.0 percent

  • Iowa: 21.7 percent

  • Rhode Island: 21.6 percent

  • South Dakota: 20.3 percent

  • Nebraska: 18.2 percent

  • Missouri: 17.0 percent

  • West Virginia: 16.7 percent

  • North Dakota: 16.1 percent

  • Mississippi: 15.5 percent

Considering the high numbers in these states, it’s clear that millions of drivers unwittingly pass over structurally deficient bridges everyday. Drivers in Nevada, Florida and Texas may be able to rest a little easier than those in other states; all three had the smallest percentages of structurally deficient bridges, with 3 percent or less of the total bridges in each state in need of repair.

Photo: The Washington state bridge collapse was a reminder to U.S. drivers about the dangers posed by our nation’s aging infrastructure. Credit: Getty Images