Here we go again with my fuzzy thoughts.
I've been thinking about twin bridges. Philly has the Ben Franklin Brigde that drops cars off a few blocks away from Liberty plaza.
Then south of that on the Delaware is the Walt Whitman Bridge that drops cars off southbound on 95 at all the sporting arenas on the left, then some oil refineries, then the airport, then I believe more oil refineries. East of all this are the docks.
A plane flying from the ocean up the Delaware would hit the Delaware Memorial Bridge.
I'm probably way off base but I've been thinking about this.
http://www.ieee.uta.edu/Galleries/ComanchePlantSpring2004/Comanche.jpg