Michael Manville teaches “Traffic Congestion: Policies and Politics” at Cornell University as a professor of City and Regional Planning. He has advised local, state, and federal officials about transportation policy and published multiple transport policy studies. Manville discusses the feasibility of the ‘bridge study’ excuse by the New Jersey governor’s staff for the Sept. 11 lane closings on the George Washington Bridge.

Manville says:“It’s hard to imagine any kind of traffic study that involves closing most of a bridge with zero notice. What would the point of such a study be? To find out what happens when you close lanes on the country's busiest bridge? We know that. It's like doing a study to see if dropping a brick on your foot hurts.

“Anyone could simply look back at records from when accidents occurred on the bridge to see that a closed bridge leads to terrible spillover traffic. In addition, any number of traffic models, experiences from other freeways, and of course common sense would tell you the same thing.

“Often times, one conducts a series of studies to see if you should close a bridge that needs repairs, or conducts studies on how best to deal with a busy bridge being closed. But these incidents usually involve a lot of publicity and lead time.

“For instance, when officials in Los Angeles determined that the 405 freeway needed to be closed, all sorts of effort went into determining how best to do that. But the result of those studies was a huge public relations campaign, and about a year's worth of notice to drivers that the highway would be closed.

“So from a transportation planning perspective, the fact that no one is sure if a study existed, or what it was for, doesn't make a lot of sense.”