The ban, which came into effect on Thursday, only affects two roads, but it’s a big move nonetheless in a country where the auto industry is both key to the economy and a focal point for the “Dieselgate” emissions scandal. The diesel engine, in fact, is named after Rudolf Diesel, the German engineer who invented it.

Germany’s federal administrative court ruled in February that cities could ban diesel vehicles from polluted areas, despite the opposition of Germany’s federal states. The move knocked the share prices of German vehicle manufacturers, who the court said did not need to be compensated over the ban.

The ban in Hamburg—which is both a city and a state—does not apply to residents of the streets that are involved, but they otherwise hit all diesel-powered vehicles that don’t comply with Europe’s most recent (and therefore strictest) diesel emissions standards.

Angela Merkel’s government and the car companies say diesel bans are excessive, while environmentalists say they don’t go far enough. Michael Schreckenberg, an expert on transport physics at the University of Duiseburg-Essen, told the Irish Times that “individual vehicle bans are nonsense because they improve the air quality in streets affected while increasing them elsewhere.”

The Dieselgate scandal, which hit a few years ago, showed that car manufacturers such as Volkswagen were rigging the emissions-testing software in their diesel vehicles to make them seem more environmentally friendly than they were.

Both France and the U.K. have since announced plans to ban all fossil-fuel-powered car sales by 2040, and China is also pushing forward towards an all-electric future.