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Archive for the 'bridge' Category

Aug 01 2008

I-35W Anniversary

Today is the one year anniversary of the I-35W bridge collapse in Minnesota. If you don’t know what I’m talking about, check out the wikipedia article. Most of the relevant info is there.

The Interstate bridge collapsed during evening rush hour on August 1, 2007. Thirteen people died and approximately 100 were injured. The reason for the catastrophic failure of the bridge has not been determined precisely, but early findings by the National Transportation Safety Board (NTSB) pointed at an original design flaw in the Gusset Plates (details here).

This tragedy has underscored a problem that the U.S. is facing: aging infrastructure requires maintenance or replacement. According to the American Society of Civil Engineers’ Infrastructure Report Card, the price of maintaining and upgrading the United States public infrastructure (roads, bridges, airports, utlilities, harbors, buildings and everything else) at an adequate level is approximately $1.7 trillion over five years (that’s $340 billion annually). Without a continued investment you run into issues such as degrading roadways, leaking sewage systems, inadequate water supplies, congested airports, etc. It is a fact that this nation continues to grow and the infrastructure representing its nerves and veins must grow with it. Look at Singapore and Manila. Those two cities are so overwhelmed by traffic congestion (to take only one example from transportation) that almost all deliveries from the ports occur at night; the trucks simply cannot move during the day. I’d hate to see that happen to Baltimore, or Savannah, or Long Beach.

$340 billion is a very big number, but let’s remember that Congress fell all over itself to send $200 million to Minnesota to replace the I-35W bridge. If they can snap-count a number that big, I think it’s reasonable to find some additional funding on an annual basis to assist the states in replacing and maintaining the existing infrastructure. 27% of the nation’s bridges are currently rated as strucutrally deficient as of 2005 (which does not mean in imminent danger of collapse, so don’t worry too much) which is an improvement from several years previously, but is too high. Unfortunately, the only way to improve that number is through funding because bridges need constant maintenance and eventual replacement to keep up with the growing traffic demand.

Do I have a proposed solution? I do not. I am not a finance geek or a politician. I, along with many others in my field, see a looming problem which if unaddressed will only lead to bigger problems in the future.

So, remember the I-35W collapse. While it apparently wasn’t directly caused by insufficient funding for maintenance, it is a bellwhether for problems to come.

One response so far

Jan 21 2008

Traffic Tidbits: 21 January 2008

Too Much Congestion? Eliminate Half the Vehicles!: An odd/even system of vehicle restriction is being looked at as an option to reduce the congestion of Bangalore.

Mine’s Better!: I think my diagram of a Gusset plate is better. But at least this news story from Kansas has one, which is better than most.

Google Transit: Google’s latest foray is a trip planner that utilizes public transit. Currently it has limited coverage, but I’m sure it will go up.

I-35 Gusset Plate Failures may not be alone: The I-35 Bridge in Minneapolis failed because its Gusset plates were too thin. This may be a more pervasive problem than was first realized.

Tolls are the Way of the Future?The NY Times discusses tolling as a method of transportation funding.

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Jan 16 2008

Traffic Tidbits: 16 January 2008

Published by Bill Ruhsam under politics, bridge, tidbits

Trans Texas Corridor Public Meetings: If you’re familiar with Texas’ proposed new system of highway/transit/rail/utility corridors, you’ll be happy to know that Public Meetings for the first section are under way. The Trans Texas Corridor is a system of highways separate from the existing Interstate Highway system, intended to move things at high speed from one point to another. They will not go through cities, like the Interstate system does.

I-35 Bridge Collapse Interim Finding: The NTSB has issued a statement about the I-35W bridge collapse in Minneapolis. Apparently, the Gusset plates were undersized, which may have contributed to the collapse.

From the Press Release:

“Although the Board’s investigation is still on-going and no determination of probable cause has been reached, interim findings in the investigation have revealed a safety issue that warrants attention,” said NTSB Chairman Mark V. Rosenker. “During the wreckage recovery, investigators discovered that gusset plates at eight different joint locations in the main center span were fractured. The Board, with assistance from the FHWA, conducted a thorough review of the design of the bridge, with an emphasis on the design of the gusset plates. This review discovered that the original design process of the I-35W bridge led to a serious error in sizing some of the gusset plates in the main truss.”

It’s my understanding that some of the Gusset plates on the I-35 bridge were found to be half as thick as they should have been. In this type of bridge, these are critical structural members. Here is a quick diagram of a Gusset plate:
Diagram of a common use of Gusset plates

Interstate 35 Bridge as Compared to State Budget: The Governor of Minnesota has released his recommendations for transportation funding for the next year. It looks like he’s asking for $2.1 billion in assorted funding. The new I-35 bridge has a budget allocation of $250 million, 100% of which is Federal Funding, not impacting the state budget. Nice bridge.

2 responses so far

Sep 20 2007

Traffic Tidbits: 20 September 2007

Traffic Congestion in India: American drivers are exceptionally tame and law-abiding compared to some of our brethren in other countries.

Transportation Alternatives Advocate for New York Non-Automobiles: Do you live or work in NYC? Do you walk or bike? Then read the Transportation Alternatives website.

Texas Transportation Institute Urban Mobility Report: The TTI Urban Mobility report for this year is out, dealing with 2005 data. Congestion is up; that’s no surprise. Time spent in traffic climbed to 4.2 billion hours in 2005, up from 4.0 billion. The full report can be found at the TTI website.

Green Vehicles in Frankfurt: I’m continually amused by the transition of the adjective “green” from “this thing is colored green” to “I’m a super-duper world-saving environmental process/vehicle/practice/industry”. Inhabit reports on green vehicles at the Frankfurt Motor Show.

I-35 Bridge Rebuilding Contract Awarded: Minnesota has awarded a contract to Flatiron Constructors Inc. to rebuild the collapsed I-35E bridge. The Price? $233.8 Million. A bargain.

No responses yet

Sep 17 2007

Traffic Tidbits: 17 September 2007

Bicycle vs. Automobile: News about the ongoing conflict between bicycles and larger motorized vehicles, out of San Diego.

Increase Safety be Reducing Comfort: A German town has followed the lead of several Netherlands projects by removing traffic signals and stop signs and other positive control devices. The theory is that with less direction, drivers/pedestrians/cyclists will be forced to pay more attention and act accordingly.

Teen Driving in Kansas: Kansas is pursuing more restrictive teen-driving regulations in order to gradually ease teens into the driving milieu. Statistics show that teen drivers are more likely to get into collisions not because of drinking or cellphone use, but because of inexperience.

Transporting Chickens: Don’t drive with chickens in your trunk (or cocaine in your cigarettes).

I-35 Bridge Wagons are Circling
: There is blood in the water, and the scent of lawsuits in the air. Not to put to fine a point on it, but this is exactly what this case does not need. As I discussed in Episode 2, there are lessons to be learned from this tragedy, but no one will learn anything if all the time is spent trying to sue someone with deep pockets.

No responses yet

Aug 23 2007

Traffic Tidbits: 23 August 2007

Internal Documents from MnDOT About I 35W Bridge Maintenance: The Star Tribune of Minneapolis/St. Paul is digging into the recent history of bridge maintenance activities and decisions.

China Trying Dictatorial Traffic Congestion Solutions: Want to cut traffic congestion?  Just ban 50% of the vehicles from the road.  It certainly cuts down on the need for driver incentives.  As it turns out, it might not make much difference.

Kerfuffle on the Zakim Bridge in Boston: Some of the plates that attach the cables on this cable-stayed bridge are a bit warped, raising questions about safety.

Urban Transportation Report Card: Streetsblog discusses the urban transportation report card, a listing of the carbon-friendliness of some American cities.

No responses yet

Aug 20 2007

Episode 2 - Bridge Sufficiency Rating and Ethical Obligations

Published by Bill Ruhsam under ethics, bridge, podcast, legal

Topics: I-35W bridge collapse; bridge sufficiency rating; ethics and legality of being a professional engineer. 

icon for podpress  Episode 2 - Bridge Sufficiency Rating and Ethical Obligations: Play Now | Play in Popup | Download

Talking Traffic Episode 002 - Bridge Sufficiency Rating and Ethical Obligations

Good day, and thanks for listening to Talking Traffic, the podcast about explaining the basics of transportation issues. I’m Bill Ruhsam and I host this podcast and its sister website, talkingtraffic.org. Today is August 20, 2007 and this is episode 2, the Bridge Sufficiency Diaries. Continue Reading »

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Aug 18 2007

Traffic Tidbits: 18 August 2007

One response so far

Aug 15 2007

Traffic Tidbits: 15 August 2007

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Aug 13 2007

Traffic Tidbits: 13 August 2007

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