While the report found that the tunnels remain safe for passenger operations and there is no evidence that the tunnel linings are unsound, it notes that chlorides and sulfates have, and are continuing to cause, significant damage to key tunnel components such as the bench walls and track as well as signalling electrical and mechanical systems. It consequently highlights the need to push ahead with the Gateway Program to construct a new railway tunnel in New York.

The storm surge caused by Superstorm Sandy resulted in sea water entering both tubes of the Hudson River tunnel and two of the four tubes of the East River tunnel. Amtrak says that its engineers already conduct regular maintenance work and will carry out interim work as needed to the tunnels, but it requires a permanent solution to guarantee the tunnels long-term availability.

However, Amtrak says that due to the impact on services this complete rehabilitation programme cannot begin until after the new Gateway Tunnel is built and enters service. The Gateway Program proposes building new double-track tunnels under the Hudson River that will help increase rail capacity to and from Amtrak's New York City terminus at Penn Station.

"Public awareness of the critical needs of the tunnels is important to build regional understanding of what must be done to provide current and future train service levels into New York," says Mr Tony Coscia, Amtrak chairman. "The Northeast region needs to make the Gateway Program a priority and we must get about the business of moving it forward as fast as we can."

Amtrak says it is seeking to begin the environmental review process for the new tunnel "as soon as possible," and through this design process and additional planning work, it will develop a schedule to perform the work recommended by the report. It adds that Amtrak engineers are already working with consultants on designs to rehabilitate the East River tunnel's two damaged tubes and will coordinate with other agencies to minimise disruption to services and other projects.