Comments on CityKin: Transportation Crossroads

Mike I agree 100% with the inspections and mainten...

2008-05-12T10:28:00.000-04:00

Mike I agree 100% with the inspections and maintenance for the bridges and highway system. This effort will keep everyone safe and could foster a major domestic civil engineering enterprise with significant economic impact for Americans.

Dave, the bridge did have a design mistake 40 year...

2008-05-12T07:56:00.000-04:00

Dave, the bridge did have a design mistake 40 years ago, but the flaw was never discovered, and the bridge was not strengthened once in that time. Meanwhile the amount of heavy traffic that it held increased. This bridge may not be the best example but it should be a wake-up call for more thorough inspections and maintenance.

Shout it from the mountaintops...we need to change...

2008-05-11T23:29:00.000-04:00

Shout it from the mountaintops...we need to change the way in which we look at transportation funding.

I'm raising a point of debate with Ms. Rodins' Was...

2008-05-11T11:44:00.000-04:00

I'm raising a point of debate with Ms. Rodins' Washington Post article regarding her association
of the collapse of the Interstate 35W bridge in Minneapolis August 2007 with her comment that it
points to "a fundamental crisis. Transportation systems and structures are outmoded and stressed beyond their capacities."

I'm not certain she can use the I-35W bridge collapse as part of her
argument.

As of May 2008 The National Transportation Safety Board is still investigating the collapse
of the I-35W bridge.

Their review of the collapse has 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.

Undersized gusset plates were found at 8 of the 112 nodes (joints) on the main trusses of the bridge. These 16 gusset plates (2 at each node) were roughly half the thickness required and too thin to provide the margin of safety expected in a properly designed bridge.

While the final NTSB report has still not been written, this undersized gusset plate finding
indicates to me that the ROOT CAUSE of the failure was not a structure outmoded and stressed beyond their capacities as Ms. Rodin suggests.

http://www.ntsb.gov/Pressrel/2008/080115.html

http://en.wikipedia.org/wiki/I-35W_Mississippi_River_bridge#cite_note-SB0802-12