Anyone driving from the neighboring city of Offenbach to Frankfurt will also pass the Kaiserlei district. The city limits of Frankfurt and Offenbach meet in the Kaiserlei area. The city limits are so irregular here that it is difficult to say which area belongs to one or the other city. Actually, the two cities should be one anyway.
The Kaiserlei district, where the A 661 motorway runs, is intended for trade and services. Kaiserlei is yet only partially developed: there is a mature development to the east of the A 661, but buildings have only been developed in large parts west of the motorway in the last 10 years. With the increasing demand for building land in the Rhein-Main area, new development impulses came to the area around the former Kaiserlei roundabout (Kaiserleikreisel), which is currently replaced by a set of streets and street crossings.