Going back to the 1950s, the city of Cleveland considered alternatives for rapid transit along Euclid Avenue between downtown and University Circle.

In 1985, the city commissioned a study called the Dual Hub Corridor Alternatives Analysis/Draft Environmental Impact Statement.

The study estimated the cost of a subway along this corridor to be $1 billion and an option that involved a light rail component at $750 million.

[8] A further study in 1993 examined additional alternatives, including a bus rapid transit plan, which ultimately was selected by the RTA in 1995.

[11] In 2008, the RTA secured a naming rights deal with the Cleveland Clinic and University Hospitals for $6.25 million over 25 years and the route was renamed the HealthLine.

Between Public Square and East 107th Street, all stations have raised platforms that align with the floor of the rapid transit vehicle, easing boarding and alighting.

[13] Between Public Square and East 105th Street, Euclid Avenue has two "bus only" lanes close to the inner median which only allow HealthLine vehicles passage, reducing delays due to conflicts with general traffic during busy times.

The vehicles have two doors on each side and run on a diesel-electric hybrid motor system, producing 90% fewer carbon emissions than conventional diesel buses;[18][19] a Caterpillar C9 low-sulfur diesel engine generates electrical power to run smaller electric motors mounted on each of the wheels.

[20] Each vehicle also has a GPS locator on board, which allowed automated traffic signals to give the HealthLine buses priority at busy intersections, until the feature was discontinued.