Tappan Zee project manager Michael P. Anderson said the bridge”™s steering committee has recommended that the replacement of the span is “the only reasonable alternative to be considered in the draft environmental impact statement (DEIS).”
Rehabilitation is problematic because it doesn”™t facilitate transit or address safety problems, as well as retains serious vulnerabilities, Anderson said.
“The bottom line is that we had an important task to accomplish,” Anderson said during a meeting of the Stakeholders Committee/Stakeholders”™ Advisory Working Group at the Westchester Marriott on Oct. 16. “This is one of the biggest decisions in terms of public works infrastructure investments that this state has had to make in a very long time, if not in its history.”
The steering committee is comprised of the executives of the Thruway Authority, Metro-North Railroad and the state Department of Transportation. All, according to Anderson “have made a consensus recommendation on the path to follow in the DEIS.”
Mark Roche, a consultant, said replacing the bridge is the best option.
“What we found was that the changes that we”™d have to make to the existing bridge were enormous, and in fact when we incorporated those changes we found that all the other criteria, the environment, the transport and the cost, became very similar across all the alternatives from all the options,” Roche said.
Roche said the three-mile bridge is safe, meaning it”™s strong enough to carry its load, but safety is diminishing as wear accumulates. In terms of fracture and fatigue, the bridge complies, but in terms of extreme events, the bridge does not comply with the code requirements.
“What”™s happened over the past five to six years is that the condition of the bridge is actually going down,” Roche said.
Anderson said all of the rehabilitation options require extensive work, and “the costs are comparable to the replacement options, and the river impacts are comparable in all of the options.”
“We are quite confident that all of the replacement options will easily have a 100-year lifecycle before we need to do any sort of major remedial work,” Anderson said. “Conversely, when you look at the rehab options, due to the fact that they retain those features that will continue to deteriorate, within 40 years we will have to revisit the bridge again.”
