Due to high levels of air pollution in the Ruhr Area, a Clean Air Plan was introduced in the Ruhr region for the first time on 4 August 2008.
The Regional Governments of Düsseldorf, Münster and Arnsberg have developed three partial plans for Ruhr Area West, North and East with the cities, and have compiled these to form an overall plan. With 110 individual elements in the sectors of trade, industry, private households and transportation, it is hoped that air quality can be sustainably improved.
As a major transportation measure, on 1 October 2008 there were nine environmental zones set up in the Ruhr Area, including in Essen, with a total area of around 225 square kilometres.
Uniform regulations applied to all environmental zones (e.g. prohibition on driving motor vehicles without stickers and exception regulations).
As the improvement in air quality achieved thus far is not yet sufficient to meet the statutory limit values for fine particles (PM10) and nitrogen dioxide (NO2), an advanced version of the Clean Air Plan came into force on 15 October 2011. As a result of this new Clean Air Plan, the environmental zone has been expanded.