How was that new Minneapolis bridge to replace the fallen one built so quickly?

Seriously… it usually takes years and years to spec out and complete a major infrastructure project like that, and it was done in just over a year.

Looks nice too!

http://www.dot.state.mn.us/i35wbridge/rebuild/designbuild.html

Probably the same way the Los Angeles highway that collapsed in the earthquake was rebuilt so quickly. You figure out what it will normally cost. Take the bids and include a bonus clause for finishing ahead of schedule. You’d be amazed how fast contractors can work when they see free money at the end of the tunnel.

The high profile aspect of the project allowed the State, Federal, City and other regulatory authorities to forego many of the processes they normally require. More of that later. They also allowed a design-build process which, luckily, the Minnesota Department of Transportation (Mn/DOT) has recently implemented in some other large projects. (They worked the bugs out of the system elsewhere.) This allows the contractor to design the project and build it instead of having an outside consultant (or Mn/DOT) first design it, get approvals, and then go for bids. It allows some working in parallel instead of a series of events. They can be working on the overall concept and design the foundation while they are removing the old bridge. Then they can design the next part while the foundation is being built, and so on. They had independent engineering teams check calculations as they completed each part instead of the normal method of reviewing the entire design when it is all done. There were a lot of techniques not normally allowed to fast track the process.

When you spend Federal Transportation Funds, you normally need to write a Project Development Report. I’ve written six of them for various projects and they typically take about 4-6 months to get approved. Part of the process is getting clearance from regulatory authorities (Corps of Engineers, US Fish & Wildlife, DNR, etc.) The report wasn’t required for this project and everybody gave quick approval. (“Gee, there was a bridge there before. We need a new one. I’m in the spotlight. I guess I won’t make them jump through the hoops to prove that we aren’t damaging the environment.) I’ve also had pedestrian bridges held up during Mn/DOT review for 4 months while they whined about minor things they didn’t like.

The Contractor also worked 3 shifts/24 hours per day, almost every day. (Often 7 days per week.) They normally can’t afford that. We also had a mild winter that minimized winter delays. The local residents were told to put up with the constant noise, a move that ordinarily would not have been allowed either. They got a large incentive for finishing early (IIRC $20 million, or $200,000/day up to 100 days.) Normally the local administrations don’t like to pay incentives, just require financial penalties for going over contract time. This helped the contractor to afford the extra crews and overtime pay. I heard one report where the Contractor said that they pretty much spent the incentive payment so it is not pure gravy for them.

For any other bridge project in this location the City of Minneapolis would have been allowed to review and comment on/object to the design. This time they were basically told to OK it or they would be cast as the bad guys. They still argued that it should be designed to accommodate future light rail transit, something that was not in Mn/DOT’s initial concept plan but that they grudgingly included.

So, in summary, it happened so fast because people worked together, it was put on an incredible fast track, and any groups that could have held up progress knew they would get a lot of bad publicity if they acted as they usually do. It’s amazing what people can do when they know it is critical and that the spotlight is on them It’s frustrating that it does not happen more during normal operations.

Phil
(Civil Engineer in road design, Twin Cities and outstate Minnesota, 26 years experience)

That was a very elegant answer, Mycroft H. Bravo.

Thank you. As you can imagine, I’ve kept an eye on the project out of professional curiosity. I’m not a bridge engineer, but have managed pedestrian bridge projects and hired bridge consultants. I left out a lot of the cynicism I’ve developed for some of the players. (Mostly PFAG Pawlenty.*)

By happenstance last Monday I had a meeting at the University of Minnesota, adjacent to the bridge. As I left, I turned on the public radio station where they were presenting a news conference being held on the bridge. I looked to my right and saw the crowd on the bridge holding the conference. Quite surreal.

(* Pathetic Excuse for a Governor.)