ALBANY (AP) -  Gov. Andrew Cuomo is pushing ahead with efforts to gauge interest in building a tunnel under Long Island Sound.

The Democrat on Friday said the state Department of Transportation has issued a "request for expressions of interest" in the project. It invites input on logistics, environmental impact and costs that will be used to develop an official "request for proposals" to build the tunnel.

A recently released study conducted for the DOT said the idea for a tunnel connecting New York's Westchester and Long Island shores or linking New York to Connecticut is feasible, but would be costly.

The study estimates a tunnel could cost up to $55 billion, depending on which option is selected.

DOT officials say they'll be talking to people in private industry to gauge interest in the idea.