[1] Between 2002 and 2018, the Busbetrieb Aarau formed part of an umbrella brand, the AAR bus+bahn, along with the Wynental- und Suhrentalbahn (WSB).

The two companies shared some senior managers, but remained legally distinct.

In 2018, the WSB became part of the Aargau Verkehr company and the AAR bus+bahn brand was disbanded.

The Busbetrieb Aarau now operates under its own brand with its own management team.

It utilises a fleet consisting of 37 buses, of which 21 are articulated, manufactured by Solaris, Volvo, Scania and Hess.