The license to use the technology has also passed hands several times, from Westinghouse to AEG in 1988, to Adtranz in 1996, to Bombardier Transportation in 2001,[1] and most recently to Alstom in 2021.

After the tests, Westinghouse and the Port Authority of Allegheny County attempted to build a larger system, the Transit Expressway Revenue Line, which proved controversial.

[4] Political leaders were skeptical of the rubber-tired mass transit technology, and accused the Port Authority of improperly choosing Westinghouse's APM over a competing proposal for a more traditional light rail system.

As the competing Crystal Mover system grew in popularity, Adtranz began developing a new, more aerodynamic model known as Innovia, which started testing in 1999.

In addition to its sleeker appearance, the new Innovia people mover also offered greater speeds, tighter turns, full composite construction and a choice in end caps.

Amid the development of a third generation model, Bombardier decided to rebrand its entire automated transit system portfolio as Innovia.

[11] Innovia APM vehicles are assembled in West Mifflin, Pennsylvania, part of the Greater Pittsburgh Area and not far from where the first demonstration trains ran.

A loop is an enclosed system that connects multiple stations along a track or guideway that is a continuous circle or closed curve.

Pinched loops look like a dual-lane shuttle (with two parallel guideways), but trains can go from one track to the other changing direction via switches at each end.