structural:expansion
Roads

Road building had been a major issue in the 1920s under the leadership of mayor Konrad Adenauer. The first German limited-access road was constructed after 1929 between Cologne and Bonn. Today, this is the Bundesautobahn 555. In 1965, Cologne became the first German city to be fully encircled by a motorway ring road. Roughly at the same time, a city centre bypass (Stadtautobahn) was planned, but only partially put into effect, due to opposition by environmental groups. The completed section became Bundesstraße ("Federal Road") B 55a, which begins at the Zoobrücke ("Zoo Bridge") and meets with A 4 and A 3 at the interchange Cologne East. Nevertheless, it is referred to as Stadtautobahn by most locals. In contrast to this, the Nord-Süd-Fahrt ("North-South-Drive") was actually completed, a new four/six-lane city centre through-route, which had already been anticipated by planners such as Fritz Schumacher in the 1920s. The last section south of Ebertplatz was completed in 1972.

In 2005, the first stretch of an eight-lane motorway in North Rhine-Westphalia was opened to traffic on Bundesautobahn 3, part of the eastern section of the Cologne Beltway between the interchanges Cologne East and Heumar.