Chestnut Hill Avenue has two low-level platforms, serving the B branch's two tracks; the stop is not accessible.

Just to the west of the station, there is a wye connecting the B branch to non-revenue tracks that run along Chestnut Hill Avenue to Reservoir Carhouse at Cleveland Circle.

The tracks are used to supply the B branch with cars before rush hour, as the carhouse at Boston College has limited storage area.

It struck a nearby utility pole, which brought down the overhead wires, causing the light rail vehicle to catch fire.

[6] In May 2024, the Federal Transit Administration awarded the MBTA $67 million to construct accessible platforms at 14 B and C branch stops including the combined Chestnut Hill Avenue/South Street station.