The rating on that bridge in Minnesota got a 50? Do you know where to see other ratings of bridges?

Question

The White House briefing said that bridge in Minnesota that collapsed got a 50 rating in the recent inspection. Do you know any way to see what the ratings are for other bridges? I'm just curious if any of the bridges in my area have similar ratings.

Answer 1

You can contact the DOT in your state and ask, under the freedom of information act, to see the inspection reports for specific bridges or for all the bridges. You can also go to the DOT websites and see if the reports are there. The National Transportation Safety Board responds to all bridge collapses and other transportation accidents, including pipelines. The Board publishes a report on those accidents after investigations and therefore you could go to their website: www.NTSB.gov and look up bridges and review all the bridge accidents. You could also check with the NTSB and see if they will send out a safety recommendation and require that all bridges meeting the same criteria as the bridge in Minnesota be immediately inspected and reinforced or reduce the loads on those bridges until the inspections can be completed and reinforcements completed. When the news talked about a 400 ft span between bridge pins, my first thought was what is the span between pins on the Golden Gate Bridge and how vulnerable is that bridge? What about other bridges that also have 400 ft spans and how many bridges have been around for well over 60 years and have spans longer than 400 feet?

What about the bridges in the Florida Keys? What about the bridges over ravines and now what about the new overview of the grand canyon which is nothing more than a horseshoe shaped bridge jutting out over the Grand Canyon? The collapse of this bridge is truly a wakeup call for all citizens. We need to wake up and check these out. Oh, and what about all the bridges in LA that have the additional threat of earthquakes? There should never be a prohibitive price for safety -- safety first regardless of cost.

Why not become proactive and demand that our infrastructures be repaired and maintained before we send money to foreign governments or foreign aide?

Answer 2

That is a good question.

According to CNN, the bridge had had several inspections in which problems were found, but the bridge to be declared to be safe, despite the deficiencies.
http://www.cnn.com/2007/US/08/02/bridge.structure/

Some bridges are just poorly designed, such as this one in Omaha http://safetransit.astcorp.com/news/news_article.php?article=8

I found a lot of information on the Internet (see links below) but most of it is pretty technical, probably intended for civil engineers who specialize in bridge structures. However, here is a statement by a lawyer on the possible consequences of the state of Connecticut cutting back on bridge safety inspections.
http://hartford.injuryboard.com/premises-liability/ct-dot-cuts-backs-on-bridge-safety-inspections.php

For more info on the bridge that collapsed in Connecticut, here is the NTSV National Transportation Safety Board investigation results on that disaster
http://www.ntsb.gov/publictn/1984/HAR8403.htm

Different states and countries use different systems for doing what about bridge safety. Here is info on what they are doing in Oregon. It sounds to me like they are applying SOME, but not all, of the reccommendations of ASCE (see links at bottom).
http://blog.cleverly.com/permalinks/265.html

Bridges can be inspected for safety many ways, such as visually looking for cracks. But different ways are needed to combine information from different sources. Here is a link to how inspections are done with ultrasound.
http://www.pulseplanet.com/archive/Feb96/1198.html

There are several different agencies with responsibility for safety on the highways and bridges and so forth, many of them under federal and state DOT = Department of Transportation. Here is info on safety on the roadway itself, not so much the structures that hold the overpass up so it not collapse, like recently in California, or prevent a bridge from coming down.
http://safety.fhwa.dot.gov/roadway_dept/road_hardware/index.htm

Apparently a few years ago the Department of Transportation made some changes in how bridge safety was measured, and here is a link to a technical explanation of that change. I wish it was not so heavily laden with unfamiliar acronyms
http://www.fhwa.dot.gov/bridge/bridgeload01.cfm

California has had some bridge collapsing at the time of an earthquake. Here is info on that.
http://www.dot.ca.gov/dist4/eastspans/index.html

But that is not the only reason why bridges go down. Here is NTSB report on a bridge that collapsed in San Diego http://www.eng.uab.edu/cee/faculty/ndelatte/case_studies_project/Schoharie.htm

Here is Minnesota Department of Transportation web site with information on Bridge rating ... this stuff may be too technical for the average non-engineer
http://www.dot.state.mn.us/bridge/DocumentsFormsLinks/index.html

Here is Colorado Department of Transportation web site with documentation on bridge inspection and safety standards. It is also a bit technical. http://www.dot.state.co.us/Bridge/RatingManual/Rating_Manual.htm

Here is Wyoming Department of Transportation system for analysiing the data
http://www.dot.state.wy.us/Default.jsp?sCode=hwyba

Here is info on a system for measuring bridge safety that was being used by Canada in the 1970's
http://www.gov.ns.ca/tran/highwayops/bridgereport.asp

Sometimes it does not matter how safe the bridge can be made. Here is info on the plane crash into bridge near Washington DC http://www.roadstothefuture.com/AirFlorida_SubwayDis.html

There are associations for the types of engineers who specialize in bridge infrastructure design and safety. You can buy some of their text books here.
https://www.asce.org/bookstore/book.cfm?book=3833

ASCE = American Society of Civil Engineers
http://www.asce.org/pressroom/news/policy_details.cfm?hdlid=132