PORTLAND – State officials are studying the feasibility of building an elevated rail line through much of the Portland peninsula to get Amtrak trains through the city.

The Department of Transportation previously considered building street-level crossings but federal officials warned that the crossings could snarl traffic at highway interchanges and create safety hazards.

So the state is proceeding with a determination of how much it would cost to build an elevated track.

The track would run from Deering Oaks, over Forest Avenue and the Franklin Arterial, under the Interstate 295 ramp at Washington Avenue, then along the mouth of Back Cove on a bridge ending behind the Burnham & Morrill plant.

State Transportation Director John Melrose says that elevating the line would cost at least $20 million – twice the cost of a street-level line.