Limits & Clean Air Programme
All EU member states must comply with thresholds for particulate matter (PM10) and nitrogen dioxide (NO2). These air pollutants can cause health problems for the population, in particular in metropolitan areas. But they are also harmful to the climate. In big cities the main cause for exceeding the thresholds for particulate matter and nitrogen dioxide is road traffic. For all areas and conurbations where the threshold is exceeded the EU member state concerned must implement plans or measures to reduce air pollution and comply with the threshold.
Therefore in 2005, the State of Baden-Wuerttemberg adopted the first Clean Air Programme for the State Capital Stuttgart. This already included numerous measures that led to a significant improvement in air pollution in Stuttgart, but not yet to a citywide compliance with thresholds. For this reason, the Clean Air Programme has been updated in several versions in recent years and additional measures have been initiated.
Measures & successes
The measures taken since 2005 have included the introduction of the low-emission zone, a ban on trucks driving through the city and the stabilisation of traffic. The city is committed to improving the air in Stuttgart on a sustainable basis. The aim is to further improve the quality of life in Stuttgart and reduce air pollutants, congestion, noise and stress through a variety of activities. The extensive package of measures comprises investments in public transport, bike and pedestrian traffic, traffic flow measures, more urban green areas for the city climate, projects such as air filter columns or road cleaning. The measures taken by the City of Stuttgart also included the fine particulate matter alarm from 2016 to 2020, an action which has been unique in Germany.
Thanks to the variety of measures taken, the pollution due to particulate matter and nitrogen dioxide has decreased in Stuttgart over the past years. In 2018 and 2019 the statutory particulate matter thresholds were met at all measuring stations in the city. In contrast to particulate matter, the nitrogen dioxide values are still above the threshold. However, here again there are significant improvements.
Traffic ban for diesel vehicles
To comply with the nitrogen dioxide thresholds in the Stuttgart low-emission zone as quickly as possible the State of Baden-Wuerttemberg had to introduce traffic bans for certain diesel vehicles.
As of 1 January 2019 the State of Baden-Wuerttemberg launched a zonal traffic ban for all vehicles with diesel motors with the emission standard Euro 4/IV and lower. The traffic ban is applicable all year round in the low-emission zone of the City of Stuttgart. Stuttgart residents have been subject to the diesel traffic ban as of 1 April 2019. In addition, there has been a route-related traffic ban in the Stuttgart city area as of 1 January 2020 for all diesel passenger cars of emission standard Euro 5 and lower. This was also resolved by the State of Baden-Wuerttemberg.
The diesel traffic bans have been updated respectively in the Clean Air Programmes. They are based on rulings by the Stuttgart Administrative Court and the Federal Administrative Court. According to this, the State of Baden-Wuerttemberg is obliged to update the Clean Air Programme so that it contains the measures required for a quickest possible compliance with the nitrogen dioxide thresholds in the Stuttgart low-emission zone, which has resulted in the introduction of a traffic ban for certain diesel vehicles. The City of Stuttgart must comply with this order and implement the regulations.