My friend, Russell Yaffee, who has been involved with the transportation community since the early days of the Big Dig writes in with some interesting insights on the Minneapolis disaster:
“What I am hearing and it is probably already been reported is that this type of bridge, Which was a common design (Arch Truss) at the time Late 60’s was a cheaper option. One of the problems with this style bridge is that it has little or no redundant structural components, so when something fails the whole bridge goes down. Newer bridges have numerous redundancies designed in. Also the bridge was supposedly slated for replacement, but I am sure that it is hard to find 100 million dollars in the DOT’s budget. I am also told it was monitored very closely and inspected often. (At least annually)”
Russell has the poop on a less serious subject as well.