NEWARK, N.J. (AP) - A new rail tunnel project under the Hudson River is taking several steps forward.

NEWARK, N.J. (AP) A new rail tunnel project under the Hudson River is taking several steps forward.

The Port Authority of New York and New Jersey on Wednesday announced it and Amtrak will contribute a combined $70 million for preliminary engineering work. They're also finalizing the structure of a development corporation to oversee the project.

Federal transportation officials announced they'll accelerate environmental reviews to push the project forward.

The existing rail tunnel is more than 100 years old and at maximum capacity. It suffered damage during Superstorm Sandy that Amtrak says will force it to close its tubes for repairs within 15 to 20 years.

The tunnel is part of a broader Amtrak upgrade program that's expected to top $20 billion and take roughly 15 years. The tunnel could be completed within 10.