Travel behavior changes after network disruption as well as after the replacement of disrupted links are not well-understood. The first table shows the number of river crossing trips by type of facility before and after the collapse and the reopening. We discover 46,000 lost trips daily after the collapse (nearly a third of what the […]

At the request of Mn/DOT, shortly after the collapse, Feng Xie and I estimated the Twin Cities 7-county region daily vehicle hours of travel with and without the Bridge using a planning model under two assumptions. The first kept the trip table fixed. This means that people did not change the number of trips, or […]

Some will say the Bridge collapse was not about money. Throwing money at the Bridge would not have kept it from falling. Others note money could have bought: more inspections, a structural (e.g. finite-element) model of the Bridge, better, faster repairs, the ability to replace the Bridge sooner. Money could have been spent more wisely. […]

The I-35W Bridge collapse occurred before the advent of Twitter, when there were only 50 million users of Facebook (as February 2012 there were 845 million users, and growth in user numbers seems to be leveling off). [I joined Facebook on November 13, 2004, so they tell me, when Facebook had fewer than 1 million […]

Bridges are designed to overcome gravity. They take travelers over a trench, river, or chasm of some kind to reduce the costs of travel. In their absence, travelers would need to descend, and ford a river, take a ferry, or make some other less convenient accommodation. Bridges are networks, sometimes simple, sometimes complex, for transmitting […]