In January 2005, the CTA purchased 13 used Orion I buses from Pace, Chicago’s suburban bus system. The buses were 96-inches wide instead of the normal 102-inches and replaced the 4900-series TMC RTS buses which were the same width. Narrower buses are primarily used for University of Chicago routes, which run through narrow streets in the Hyde Park neighborhood.
The 4915-series Orion I buses were built in 1990, however were in better condition than the 4900-series despite their slightly older age. Additionally, unlike the 4900-series, the Orion I buses were accessible.
The CTA retrofitted the buses with its automated announcement system and repainted them with CTA’s standard white, blue, and red paint scheme.
The 4915-series buses were eventually replaced with 30-foot Opus buses from Optima Corporation. The 4915-series was retired by June 2007.