NYC Manhattan West Side Highway- Old & New
new box tunnel beneath Riverside Drive boulevard extension
Old= Elevated Viaduct
New= Submerged Tunnel Box
Least expensive when done with no or minimal excavation, as respectively with a tunnel box atop the existing SE Freeway segment between 11th Street and Barney Circle- Pennsylvania Avenue SE, and with an extension of that freeway to RFK Stadium.
Washington, D.C. Barney Circle
Existing SE Freeway and immediate unbuilt extension involving no heavy excavation
Tunnel Box atop existing SE Freeway segment between 11th Street and Barney Circle