 Since November 1993 the Authority has studied the so-called "Spine Line"  to the Oakland neighborhood which is the third largest center for commuters in the commonwealth and the home to Carlow University, the University of Pittsburgh, Carnegie Mellon University, the Pittsburgh Technology Center, the University of Pittsburgh Medical Center and Phipps Conservatory.Thus far the extension to Oakland has not gone beyond the design phase.The First Avenue station was added in 2001; service to Penn Station was suspended on September 2, 2007.