A single prototype was built, but declines in rail passenger traffic resulted in a lack of orders so Budd re-designed the concept as an electric multiple unit (m.u.).

Unfortunately, these remarkable statistics were accomplished at the expense of comfort, as passengers were provided with significantly reduced legroom compared to other coaches in the same class and a bouncier ride.

[2] The Pioneer III coach concept toured numerous North American railroads as a demonstrator unit, but due to the general decline in rail passenger traffic there was little interest in new rolling stock, especially one that represented a new and untested model.

The cars used the revolutionary, and aptly named, Budd Pioneer III truck, which was a lightweight, inboard bearing railroad bogie designed for high-speed operation.

In 1963, as part of an effort to improve commuter rail service in the Philadelphia area, the PRR contracted with the Budd Company to build a more advanced version of the Pioneer III design.

They all had fabricated trucks with air springs and disc brakes, more powerful traction motors, two rows of ceiling lights, improved air-conditioning, the use of an automatic MU coupler that automatically made electrical connections in addition to the usual AAR "knuckle" design and a sleeker T-shaped (Faiveley) pantograph in place of the diamond-shaped pantograph.

Although there were plans to convert the cars into locomotive-hauled coaches, SEPTA finally decided to dispose of the fleet due to the expense it would have taken to deal with PCBs in the transformers and the lack of ADA compliance.

[citation needed] In 1966 the Budd Company in cooperation with Garrett AiResearch used the surplus Pioneer III demonstration coach as the basis for the first gas turbine-powered railcar in North America.

The coach, re-christened GT-1, was to be supplied to the Long Island Rail Road for testing on its non-electrified branch lines as a way to provide high speed MU operation without the need to extend the electrification.

In 1969 the GT-1 was rebuilt using funds from the Urban Mass Transit Administration into a hybrid turbo-electric railcar, replacing the mechanical drive with an electrical generator providing power to 4, 150 hp traction motors.

Re-classified again as GT-2, the coach was intended to test gas turbine railcar operation into the confines of New York Pennsylvania Station and therefore was also given the capability to draw power from the 700 VDC third rail.