One in nine US bridges 'structurally deficient'

Divers during recovery efforts following the 35W bridge collapsed in Minneapolis 3 August 2007 A Minnesota bridge rated structurally deficient collapsed in 2007 - investigators found it had collapsed because of a design flaw

Related Stories

One in nine US bridges - more than 66,000 in total - is structurally deficient, a report has found.

Since 2008, the pace at which the US repairs bridges has slowed threefold compared to 1992-96, the report by Transportation for America, a coalition of transport interests, found.

The average age of US bridges is now 43 years, seven years short of the average lifespan, the report found.

It warns the backlog of bridges needing repair will grow amid US budget woes.

The report recommends US policymakers enshrine bridge repair and overhaul as a top priority for federal transport funds, but notes repairing America's deficient bridges will cost $76bn (£49bn).

Not necessarily unsafe
A man is seen sitting atop a car that fell into the Skagit River after the collapse of the Interstate 5 bridge there minutes earlier 23 May 2013 The Skagit River bridge, which collapsed in May, was rated "functionally obsolete"

In 2012, 11% of US bridges were rated structurally deficient, down from 22% in 1992. But the rate of repair has significantly slowed despite an influx of funding from President Barack Obama's 2009 economic stimulus package.

In 15 of the 50 US states, the number of deficient bridges has increased since 2011.

In 10 years, one in four bridges will be older than 65 years.

According to the report, about 260 million trips are taken across deficient bridges each day.

State progress from 2011

  • In Pennsylvania, almost a quarter of bridges are structurally deficient, the worst in the nation
  • Seven of the 10 states with the largest share of deficient bridges in 2011 have reduced their total number of deficient bridges
  • Five per cent more bridges in Arizona, Delaware, and Hawaii are rated deficient than in 2011
  • On average, Arizona bridges are in the best shape in the US

While structurally deficient bridges are not necessarily unsafe, they are generally rated in poor condition and require upgrading or replacing.

"Bridges may be rated deficient for a range of reasons and not all of them pose an immediate threat to public safety," the authors wrote.

"However, allowing bridges to remain in serious need of repair can lead to the sudden closure of a critical transportation link or, far worse, a collapse that results in lives lost and a major economic impact to the affected region."

In 2007 for instance, 13 people were killed when a bridge collapsed in Minnesota, while eight died in Texas in 2001. A bridge collapsed in May in Washington state, but no-one was killed.

Outdated

The National Transportation Safety Board eventually determined that the 2007 collapse was related to a design error, although the bridge was deemed structurally deficient at the time.

And the bridge over the Skagit River in Washington collapsed in May when a lorry hit an overhead support beam.

The bridge was rated "functionally obsolete", and Transportation for America report noted it had been built before the interstate system and was not designed "to carry the large load of today's interstates".

The American Society of Engineers, meanwhile, believes politicians are too keen to build new bridges instead of repairing old ones.

A new freeway bridge being built in Arizona collapsed on Wednesday, killing one worker and injuring another.

More on This Story

Related Stories

More US & Canada stories

RSS

Features & Analysis

  • Baby in boxStrange case

    The remarkable appeal of the Finnish baby boxes


  • WW1 gas mask being demonstratedTrench terror

    Did the soldiers of WW1 have an irrational fear of poison gas?


  • Mitt Romney, speaks at the podium as he concedes the presidency during Mitt Romney's campaign election night event at the Boston Convention 7 November 2012Aura of a loser?

    Mitt Romney looked presidential but could never pull it off


  • A woman holds up a feminist sign.PC virus

    Is liberal speech policing out of control?


Elsewhere on the BBC

  • ReadingBest books

    BBC Culture takes a look at ten books you should read in February

Programmes

  • A car being driven by Cruise Automation technologyClick Watch

    The tech which could allow any car with an automatic gearbox to become self-driving

Copyright © 2015 BBC. The BBC is not responsible for the content of external sites. Read more.

This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.