The Port Authority has decided that some expansion of rail freight between New York and New Jersey is necessary and recommends either digging a rail tunnel under New York Harbor or expanding the current system of carrying rail cars across it on barges.

The agency rejected an option to do nothing, and recommended further studies on the barge system and the no-frills rail tunnel under the harbor -- the two least expensive choices of the 10 alternatives discussed at public hearings on Long Island and elsewhere in the metropolitan area earlier this year.

The next step is another series of public hearings, next year at the earliest, on those two options -- meaning no near-term increase in rail freight that might take heavy trucks off Long Island roads.

"We will take these two options and really put them through the wringer in term of in-depth, on-the-ground environmental analysis -- taking traffic counts, testing air quality," said Mark D. Hoffer, director of new port initiatives for the agency, in an interview Wednesday.

Expanding the barge system would cost between $100 million and $600 million, according to agency documents, while the least expensive tunnel would cost more than $7 billion. The tunnel being considered would have two tracks and would be big enough to handle double-stacked cargo containers.

The Port Authority posted its recommendations on its website on Friday. It said it would accept further public comments until Oct. 26, and the lead federal agency, the Federal Highway Administration, would then issue a formal Record of Decision that would allow the next study phase to begin.

No date has been set for the next round of hearings. Construction could not begin until the next study phase is completed. Even then it would depend on the availability of funding and the approval of the Port Authority board of directors, Hoffer said.

advertisement | advertise on newsday

Suffolk County Executive Steve Bellone said in a statement that he recognized the need for more rail freight, but cautioned that the next phase of the study "must identify the magnitude and extent of any potential adverse effects to affected communities and develop mitigation strategies in collaboration with those communities."

The Brookhaven Rail Terminal in Yaphank, expected to be a beneficiary of any increase in freight traffic on Long Island, declined to comment Wednesday.

A coalition of civic groups in Queens, which is the switching point for rail freight to and from Long Island, criticized the recommendations and said they did nothing to stop the shipment of open freight cars now carrying Long Island garbage through Queens.