When the traffic sign “270.1-40” was introduced more than 15 years ago, it was hotly contested. It measures 60 centimeters square, with a red prohibition circle in the middle and the word “environmental zone” in the middle. The sign even made it into the House of History in Bonn as an exhibit. Now it is a discontinued model.
Because the environmental zones are being abolished at an ever faster pace. In Baden-Württemberg, where there were a lot of them for a long time, the requirement for a green sticker was abolished in several cities at the beginning of the year, including Heidenheim and Heilbronn. Reutlingen, Tübingen and Ulm will follow in June.
This continues a trend from the past two years. While the green sticker was still required in 55 municipalities across Germany at the end of 2022, the Federal Environment Agency currently lists 42. Behind this is gentle progress on the way to better air: more and more measuring points are reporting pollution below the limit value.
In 2005, when a Europe-wide limit value for fine dust was introduced, things looked completely different. Nationwide, 40 percent of measuring stations broke the new maximum values for fine dust pollution. They were mostly located in urban areas, on traffic axes such as Am Neckartor in Stuttgart or on Leipziger Straße in Berlin. The first German environmental zones followed at the beginning of 2008, in Berlin, Cologne and Hanover. After transitional periods, only those with a green sticker were allowed in – and this required diesel cars to have a soot particle filter.
The vehicles only become cleaner after a long delay
A limit value for nitrogen dioxide followed in 2010, and in the same year 56 percent of the measuring stations exceeded the limit values. Again it was the stations on the busy streets. Again the problem mainly affected diesel vehicles. Only this time it wasn’t done with a particle filter. Exhaust gases had to be laboriously cleaned. But in the development departments of German car companies, more brainpower is spent on how to deal with “defeat devices” on test benches – so that vehicles meet all the requirements on paper, but not on the road. It is only years after the introduction of the limit that vehicles that actually comply with the requirements come onto the market on a large scale – and the Euro standards become stricter.
All of this is also reflected in the environmental zones. Almost all cities comply with the requirements for fine dust – a maximum value of 50 micrograms per cubic meter may only be exceeded on a maximum of 35 days. So far this year, only Tübingen has reported excessive values for one measuring station, on nine days so far. So far, only Osnabrück has struggled with nitrogen dioxide; the maximum value was not met four times. All other cities report zero.
New cars alone will not solve the problem, says the Federal Environment Agency
But success is relative, says Marcel Langner, head of department at the Federal Environment Agency. “The air is much better than it was a few years ago, but it still falls far short of the World Health Organization’s guidelines.” And soot particle filters and stricter Euro standards would certainly have played a large part in this. “But we won’t get good air by making the cars cleaner,” says Langner. More people would also have to switch from cars to local public transport or bicycles. An electric car does not produce any exhaust gases – but it produces just as much tire wear as a combustion engine, sometimes even more because of its higher weight. However, this tire abrasion is one of the main sources of fine dust.
And Baden-Württemberg’s Transport Minister Winfried Hermann (Greens) doesn’t think the job is done yet. “Clean air remains an important task,” he says – and he too is counting on a better range of buses and trains, more cycle paths and, unlike Langner, also on electric cars. Above all, he warns against scrapping traffic signs “270.1-40” prematurely. “In the interest of people’s health, we must not let up in our efforts to ensure clean air,” says Hermann. “Repealing the driving bans for old diesel vehicles would jeopardize the successes in air pollution control.” After all, nitrogen oxide levels in Stuttgart or Pforzheim are still well above the planned new EU limits.
Because as long as the air in Europe’s cities is not really good, the limit values remain moving targets. It was only in February that the EU Parliament, Commission and member states agreed on a new directive that is intended to improve the air in Europe again by 2030. The limit value for nitrogen dioxide should then be halved from 40 to 20 micrograms per cubic meter, and stricter values also apply to fine dust. However, the WHO guidelines are still not within reach. “The European plans are still a factor of 2 higher,” says Federal Environment Agency expert Langner.
And in any case, we still have to do a lot more to really make the air better – not just in the cities. Fine dust is also produced when wood is burned or, in a roundabout way, through ammonia emissions from agriculture. And then there is another topic that people tend to avoid in Germany: the speed limit. It’s a tough, lengthy road to good air.