Transit-oriented development is no passing fad—from NY’s Hudson Yards to DC’s Union Station, some of the biggest commercial real estate projects are rising above the busiest transit nodes in the US. Now Amtrak is looking at the possibilities at Philadelphia’s 30th Street precinct, which includes 85 acres of rail yards. The 30th Street Joint Master Plan, to be led by Skidmore Owings & Merrill (also involved in the redevelopment of Denver's Union Station), will take two years and formulate a potential multi-phase development lasting 25 to 30 years, says Amtrak chief of corridor development Bob LaCroix. He speculates that the potential for a big mixed-use project could produce a brand new transit-centered neighborhood in the spirit of DC's NoMa. (Which means Philly should start thinking of four-letter nicknames for its neighborhood. We've been to Eagles games, so we know you're good with four letters.)