Last year, nitrogen oxide levels in the Neckar valley remained below the limit value for the first time. The plaintiffs, who have been campaigning for better air for years, see this as only a partial success, however. The readings could, however, have an impact on driving bans in the city.
Diesel vehicles up to and including Euro4 have been banned in the Stuttgart cauldron for two years now, and even Euro5 vehicles since mid-2019. Last year, the city now measured a significant improvement in air pollutants for the first time. While a reduction in particulate matter levels had already been noted before, in 2020 the limit value of nitrogen oxides was also undercut for the first time.
For the plaintiffs, who have been campaigning for better air in Stuttgart since 2005, this is not yet a reason for euphoria. They mainly blame the lower traffic load due to the Corona pandemic and also a more favourable weather situation for the success. Whether the measures actually have an effect can only be seen in the next few years.
Over the last few years, the plaintiffs have already achieved some successes that have led to an improvement in air quality. In addition to the diesel driving ban, a ban on lorries passing through Stuttgart was enacted and a 40 km/h speed limit was introduced on many heavily polluted roads. A smarter traffic light system at Neckartor and a bus lane on Cannstatter Straße also allow traffic to flow better.
The plaintiffs now fear that the improvement measured last year could lead to the abolition of some rules, such as the diesel driving bans. In Hamburg, the CDU had gone ahead and demanded that the diesel driving bans in the two affected streets be lifted, since the improvement in the air meant that there was no legal basis for continuing the measures. Critics of the diesel driving bans in Stuttgart could react similarly to last year's results.
Some critics had already accused the Green Minister of Transport, Winfried Hermann, of deliberately driving up nitrogen oxide levels. This is because the measuring stations on Pragstraße were installed near a gas heating system. This is not allowed, as it drives up the nitrogen oxide readings. Whether the minister had actually tried to drive the values up is not certain. But for the critics of the driving bans, this gives new ammunition.
Whether the authorities will wait and see how the values develop or listen to the voices of the critics will become clear in the coming year. The diesel driving ban in Stuttgart, as well as the bans and environmental zones in other German cities, can of course be found in the Green-Zones app.