The air in Germany is getting cleaner. This is also the case in Darmstadt. Despite the improvement in nitrogen oxide levels, however, the city is sticking to its driving bans for older diesel and petrol vehicles.
According to evaluations by the Federal Environment Agency (UBA) on air quality in Germany, things are looking up. While nitrogen oxide limits were exceeded in 57 cities in 2018 and 25 cities were still above the permitted amount of 40 micrograms per cubic metre (µg/m³) as an annual average in 2019, exceedances had been measured in only 10 cities in 2020. However, some data will only be fully evaluated in the summer.
In Darmstadt, driving bans were imposed in June 2019 for diesel vehicles with Euro 5 and worse and petrol vehicles with Euro 2 for the heavily polluted traffic points Heinrichstraße and Hügelstraße. In 2018, the nitrogen oxide limits were clearly exceeded at 50 µg/m³ nitrogen dioxide on Hügelstraße and as much as 54 µg/m³ on Heinrichstraße.
Now, the measured values on both streets are well below the limit value - in Hügelstraße, for example, at 27.5 µg/m³. Nevertheless, the Darmstadt government is sticking to the driving bans. "We will maintain the traffic restrictions until it is ensured at all measuring points that their suspension would not lead to exceedances again," announced Lord Mayor Jochen Partsch of the Green Party.
UBA President Dirk Messner attributes the air quality success primarily to policy measures. Nitrogen oxide concentrations had dropped by a whopping 20 to 30 per cent in the first lockdown in 2020 due to the decline in traffic, yet Messner believes that this was not the decisive factor in the improvement of nitrogen oxide levels, but was instead attributable to cleaner vehicles, 30 km/h speed zones and lower-polluting buses.
Nevertheless, there is reason for concern, according to Messner. On the one hand, some cities, such as Hamburg and Munich, are still struggling with excessive nitrogen oxide pollution. On the other hand, fine dust pollution remains high and there is no improvement in sight due to non-exhaust emissions from electric cars, i.e. brake, tyre and road abrasion, even with a successful change in mobility. According to Messner, the particulate matter limit value is also outdated. In fact, the World Health Organisation (WHO) could present proposals for a new particulate matter limit value as early as this year, which could then also influence the EU's specifications.
So even if politicians see success in the policy measures, at least with regard to nitrogen oxide, the data are viewed with caution due to the lockdown. Thus, diesel driving bans will continue to accompany us this year and perhaps in the years to come.