Air cleanliness plans exist in areas with poor air quality. Environmental zones are possible measures under these plans. Environmental zones reduce dust and nitrogen dioxide emissions. Vehicles with high levels of harmful emissions are not permitted to be driven in environmental zones.
Should you wish to drive your vehicle in such a zone, you must purchase an environment sticker. There are three different colours of stickers, which are each assigned to an emissions group. The assignment of your vehicle to one of these categories depends on the emission key numbers. You will find these in the vehicle papers.
Note: The environmental zones are identified by their own traffic signs. The additional sign also includes the colours of the stickers which allow vehicles to be freely driven in the concrete environmental zone.