From Tower City to just east of East 55th Street, the Blue and Green Lines share track with the Red Line for 2.6 miles (4.2 km) along a private right-of-way originally acquired in 1930 to bring intercity trains into Cleveland Union Terminal (the site of today's Tower City Center).

The station-stops east of Shaker Square are adjacent to street intersections and consist mostly of concrete platforms with bus shelters.

The Blue and Green Lines use a fleet of 48 light rail vehicles (LRVs) manufactured by Breda Costruzioni Ferroviarie in 1980 and 1981.

The Blue Line is the direct, continuously operating descendant of the privately-owned Cleveland Interurban Railroad and later the municipally owned Shaker Heights Rapid Transit, it connected the streetcar suburb of Shaker Heights to downtown Cleveland.

They planned for a grade-separated right-of-way all the way to downtown that could significantly reduce travel times for commuters, and thus increase the desirability of their suburb.

In 1915 they acquired a majority interest in the New York, Chicago and St. Louis Railroad (the Nickel Plate Road), mainly to allow for a line next to a relocated NYC&StL.

It continued down the median of the new Shaker Boulevard to Woodhill Road, then across the Cleveland Short Line Railway (New York Central Railroad) and alongside a CSL branch to East 55th Street.

From there, the CIRR cars traveled along the tracks of Cleveland Railway's Broadway line, using street-running for the remainder of the trip downtown.

Cleveland Union Terminal (CUT) opened in 1930, along with a new grade-separated right-of-way with side-by-side lines for steam railroads and interurban streetcars, including the CIRR.

The CIRR no longer needed to run on city streetcar tracks and the ramp to Broadway and East 34th Street was removed.

In 1981, RTA undertook a complete renovation of the Blue Line, with new track, ballast, poles and overhead wiring.

To run on the renovated line, a fleet of new LRVs were purchased from an Italian firm, Breda Costruzioni Ferroviarie, to replace the aging PCC cars.

From August 20 to September 30, 2023, the Blue and Green Lines were suspended due to track, signal and station work.