The Nyegaard House on Hamburg's busy Max Brauer Boulevard was originally built as a place for destitute single women to live in peace and quiet, and aging matrons like Charlotte Lill still call it home. But these days, it's a far cry from quiet. "And clean air is a thing of the past," says the 70-year-old.

Each day, more than 20,000 vehicles thunder past the 117-year-old neo-Renaissance structure, with the boulevard considered to be one of the most polluted arterials in the city. It is only possible to open the windows at nighttime, says Lill, whose ground-floor apartment opens directly onto the four-lane thoroughfare. "We are emissions guinea pigs."

An air quality monitoring station within sight of the house provides the evidence: Emissions standards passed by the European Union in 2010 are regularly exceeded, essentially robbing residents of clean air to breathe. They have not, however, stayed quiet. Three years ago, 30 local residents launched a crusade against the city, demanding that traffic-calming measures be implemented and, ultimately, suing the city for inaction. In response, all they got were assurances that the city was looking into it or excuses that they didn't have enough staff to deal with the problem. "Nothing has happened," Lill says.

That could change on Thursday. The Federal Administrative Court in Leipzig is set to consider whether vague plans to maintain clean air go far enough or whether problematic cities like Hamburg must ensure clean air as rapidly as possible, even if that means implementing driving bans. And there is plenty to indicate that the judges will prioritize health, just as lower courts in Düsseldorf and Stuttgart have done.

The landmark decision could very well send out shock waves affecting more than 60 municipalities in which, like Hamburg, limits on poisonous nitrogen oxide emissions are consistently exceeded. Germany's major carmakers  would also be put on notice, as would the German Chancellery and the ministries responsible. All have ignored the problem for years and are hardly prepared should the court prove stubborn.

Things threaten to get even worse after that: Just a few weeks after the Leipzig ruling, the European Commission is also set to decide whether to initiate legal proceedings against Germany at the European Court of Justice for its failure to do anything about high levels of harmful emissions in its cities. Should Brussels decide to do so, it would clearly expose Berlin's cozy relationship with the automobile industry at the expense of public health. "That would be a real disgrace for the German government," says a state secretary in Berlin.

On Edge

Several city halls in Germany are on edge. "I would be surprised if we got away without driving bans," says Helmut Dedy, senior director of the Association of German Cities. The chances are significant, he says, that the Federal Administrative Court will authorize such measures.

For two years, representatives from German municipalities have been demanding the introduction of a blue environmental sticker that would denote vehicles with clean diesel engines -- cars that would then be exempted from driving bans. Dedy is imploring Germany's new government, once it is formed, to finally introduce the stickers. Transportation policymakers in Berlin have avoided the stickers "like the devil does holy water," he complains. "It's the product of a pronounced deference to the automobile industry."

Even though limits were drastically exceeded, politicians at the federal, state and municipal levels did next to nothing. Yet everyone knew where most of the blame lay: With diesel cars, more and more of which were traveling the roads of Germany cities. And most of these models were equipped with software to either curb or completely switch off emissions filtering systems in many driving situations.

VW was particularly aggressive on this front. When the practice was uncovered  in the United States in September 2015, environmental agencies in the country treated the behavior as being fraudulent and illegal. The Germans, however, took a different approach: Then Transportation Minister Alexander Dobrindt did little to curb the manipulations, in many cases being satisfied with voluntary software updates. The result is that the air in German cities remained poor.

The German government is now facing the consequences of its inactivity -- or at least it will if the court rejects the appeals from Stuttgart and Düsseldorf against driving bans. Depending on the grace period the court decides on, the cities could be forced to close down their streets within three to six months.

Preparing for Chaos

A verdict of that nature would destroy billions in value because drivers would suddenly be unable to drive into the city for work or to go shopping. Cars that already have to be marked down significantly in many places could then only be sold in foreign countries.

Millions of cars would be affected by the ban and there is a possibility that even delivery vehicles and trucks belonging to craftsmen would not be permitted. Normal city life would be rendered impossible.

In order to prepare for the chaos such a court ruling would bring, Dortmund is laying the groundwork to enable the issuing of hundreds of exemptions overnight for emergency and old-age care services, food deliveries and city service vehicles. The aim is to ensure that supplies and provisions continue to reach areas where roads might be closed.

The federal government in Berlin is also slowly starting to address the issue. Chancellor Angela Merkel's chief of staff, Peter Altmaier, sat down at his computer shortly after coalition talks for the next government had been successfully concluded and wrote a remarkable letter to the European Commission, apparently hoping to put them in a lenient frame of mind. He announced a long list of instruments to combat nitrogen oxide that the government had until recently rejected out of hand. He even proposed eliminating charges for public transportation "to reduce the number of private automobiles."

The idea triggered a passionate public debate last week on the pros and cons of such a step. Government spokesman Steffen Seibert had to quickly step in with qualifying details, saying the idea was limited to days when driving was prohibited.

In the excitement over the public transportation discussion, three additional points in the letter Altmaier sent to Brussels were largely overlooked -- ideas that had previously been rejected outright by Berlin. One noted that Berlin intended to change traffic laws to enable the closure of individual streets and another involved legal changes to allow the government to require car-sharing companies and taxi companies to use electric cars.

A Huge Burden

And then there was a proposal that likely got the attention of automobile executives in Germany: Emissions are to be reduced, Altmaier wrote "with additional technical measures." The meaning is clear: The federal government intends to force car companies to retrofit millions of dirty diesel vehicles that emit far too much nitrogen oxide during real driving conditions.

Thus far, the automobile industry has refused to consider such measures, and not just when it comes to retrofitting personal vehicles, but also city buses, which are a significant part of the emissions problem.

That now puts a huge weight on the shoulders of Germany's municipalities, which have already had to carry most of the burden stemming from the diesel problem. In North Rhine-Westphalia alone, Germany's most populous state, more than 30 cities in 2016 violated the legal limit of 40 micrograms per cubic meter of air.

They have very few cards in their hands as they seek to avoid the approaching traffic chaos -- despite promises from Berlin that municipalities affected will be granted millions in aid money to assist with the acquisition of clean buses and modern traffic-control systems.

Such measures could help lower the nitrogen oxide values. But many cities can't even afford the apparently generous offer from Berlin. Often, the municipalities where air quality is particularly dire are the same ones struggling with huge mountains of debt. Essen, Hagen, Oberhausen, Remscheid and Mühlheim an der Rühr are all enrolled in a program aimed at eliminating new debt and balancing their budgets after years of profligacy. They simply have no money for modern buses, even if Berlin reimburses them for part of the purchase price of clean vehicles.

A single electric bus costs up to a million euros, whereas a diesel bus can be had for less than half that amount. Currently, however, the federal government is only prepared to reimburse 40 percent of the extra costs associated with purchasing electric buses. Assistance in excess of that amount must be approved by the European Union, since it could be seen as illegal state aid.

The German Environment Ministry has filed a request in Brussels to allow the German government to assume up to 80 percent of the costs, but the approval process could take months -- valuable time that is being lost. "As a result, many municipalities and public transportation services are sitting like a rabbit in front of the snake and waiting to see what happens," says Ulrich Jaeger, head of the municipal utilities in Wuppertal. Their problem isn't purely financial in nature; the conventional diesel buses are also difficult to replace from a technical point of view. Very few producers even sell electric buses, and the distances they can travel are limited. They have to be charged during the day and the necessary infrastructure for doing so isn't yet in place. Plus, they aren't suitable for all terrain.

Ignoring the Shift

Wuppertal tested battery-powered buses two years ago and found that the electric vehicles had problems with some of the steeper hills in the city. "Either the batteries emptied too quickly or had to be charged on their routes, so they wouldn't get stuck on the hills," says Jaeger.

Buses equipped with fuel cells could help. They have extensive range, do not emit harmful fumes and have long lifespans. Wuppertal has already ordered some of the buses and would like to expand its fleet, but the acquisition of such buses is not currently being subsidized.

German producers long ignored the shift to electric powered vehicles and are still addicted to their diesel technology. Andreas Renschler, head of commercial vehicles at VW, isn't currently planning a radical shift to e-mobility, preferring instead to focus on the newest diesel technology. "With new vehicles conforming to Euro 6, emissions of nitrogen oxide can be reduced by 80 percent," he says.

The VW executive does admit that the majority of German cities will ultimately rely on electric-powered vehicles, but his company doesn't currently have the necessary solutions on offer. VW doesn't yet sell its own electric buses, with serial production only set to begin next year. Rival Daimler has also targeted 2019 for the launch of its own electric buses.

It is a position with which those in charge of public transportation in German cities are unhappy. Cities like Hamburg, Berlin and Wiesbaden want to immediately augment their fleets with future-oriented technologies. "Buses with diesel technology are not a solution with a future for us," says Henrik Falk, head of Hamburg's public transportation utility. The reason is simple: Vehicles that conform to the Euro 6 standard may emit less nitrogen oxide, but they still emit plenty of CO2.

What would help Falk and his counterparts across Germany, aside from high-performance electric buses, is after-market technical improvements for their fleets, including modern emissions systems. Such retrofits could be implemented at a cost of just a few thousand euros per bus. The companies, though, are uninterested in the associated effort and costs. They claim that retrofitting results in lower fuel efficiency, resulting in even higher CO2 emissions.

The truth is that the automobile industry would rather sell new buses than retrofit old ones. They stand to earn billions when municipalities refresh their fleets of buses, garbage trucks and street cleaners with the help of state subsidies. It's no wonder, then, that VW, Daimler and the rest have begun posing as champions of clean city air. "Those looking for immediate improvements in air quality should quickly modernize their fleets," says VW executive Renschler.

Ruffling Feathers

That kind of marketing verbiage not only ruffles feathers in insolvent municipalities -- it also angers the federal government. Berlin has recently adopted a more aggressive approach to the automobile companies and is demanding that they develop so-called SCR catalyzers for retrofitting diesel vehicles. Under orders from Berlin, transportation agencies are currently bombarding the companies with official recall decrees.

After tens of thousands of VW diesel automobiles, it is Daimler's turn for an official recall this week: Investigators have apparently found a particularly innovative manipulation technology inside the Vito van. The vehicle's engine management system was apparently programmed so that the amount of diesel exhaust fluid (AdBlue) -- used to reduce nitrogen oxide emissions -- injected into the SCR catalyzer was reduced to ensure that the fluid would not have to be refilled prior to the next scheduled service appointment. The consequence was that in many driving situations, the car would emit more nitrogen oxide despite being equipped with emissions reduction systems.

According to sources within the Transportation Ministry, the mechanism is an overtly illegal switch-off device. Investigators had long been searching for the mechanism responsible for the manipulations. Now that they have found it, they believe they will find it elsewhere as well. When contacted, Daimler denied the allegations. "There is no causal relationship between the service interval and the usage of AdBlue," a spokesman said and threatened the Federal Motor Transport Authority (KBA) with "all legal means at our disposal."

VW is also facing more trouble. In conversation with company representatives, Berlin has mentioned the possibility that type approval -- official confirmation that a vehicle model meets legal specifications -- may be revoked for the Porsche Macan. Investigators have found up to five questionable software functions in the vehicle, which they see as a particularly brazen violation. Were the type approval revoked, the Stuttgart-based manufacturer would be forced to buy back several thousand vehicles. VW says it is currently working with KBA to find a solution.