The corridor along which the Red Line runs had been planned for use since before 1930 when the Cleveland Union Terminal opened.

The current fleet of Red Line cars underwent an in-house rehabilitation under the direction of the former director of rail Michael Couse.

Cars received pantographs and controllers, along with rebuilt trucks, traction motors, resistor banks, new flame-retardant flooring, LED lighting, new seat frames, revised interior paneling, and additional open space for improved ADA compliance.

When the extension to Hopkins Airport was being built in 1967, a fleet of 20 longer cars was purchased to supplement and replace the Blue Birds.

The cars, which had a stainless steel exterior with red and white trim and featured interior luggage racks, were promoted as "Airporters."

In April 2019, a study recommended that 34 new cars be procured in 2020 for delivery in 2023, but the subsequent COVID-19 pandemic may have delayed this.

During a board meeting in January 2020, a contract was awarded to LTK Consulting to prepare specifications.

The Red Line is prominently featured in the final scenes of the film Proximity, starring Rob Lowe and James Coburn.

The finale involves a hostage on a Red Line train and a gunfight and chase scene through the Tower City station.