Between 1990 and 2017, NOx emissions in Germany caused by road traffic fell by around 70 percent. This reduction is all the more remarkable because in the same period, the vehicle population increased markedly by over 50 percent.
Source: Kraftfahrt-Bundesamt, Umweltbundesamt
In fact the number of diesel cars more than tripled. And total vehicle mileage also increased by one third. In short, although there are more vehicles on the roads, the air in the cities is getting better and better. The reduction in NOx emissions is therefore due to the improved engine technology of the vehicles.
Our goal is clear: no exceeding of the set limits in our cities – as quickly as possible. In 2014, increased NOx levels were recorded at 149 measuring stations across Germany - by 2018, that had been cut to 57. Although 57 is still too many, the trend is heading in the right direction. Incidentally, it is also a fact that since as early as 2015, no violations of limits have been recorded by the urban background measuring stations.
A study by the Karlsruhe Institute of Technology (KIT) in Stuttgart in autumn 2017 showed that NOx levels were already halved just 25 to 30 meters from the measuring stations set up near busy roads.