For many European cities, diesel exhaust emissions have become a health as well as an environmental problem.

So in addition to promoting electric cars or alternative forms of transportation, lawmakers are beginning to crack down on the dirtiest diesels.

Next year, the French government will launch a car identification system that will rank vehicles by the amount of pollution they emit.

According to Reuters, this will allow local authorities to limit city access for the worst-polluting cars.

The move – announced in a speech by French Prime Minister Manuel Valls on Friday – is part of an effort to gradually phase out diesel fuel in the country.

In the 1960s, the French government and auto industry made the decision to move to diesel – which was viewed as less polluting than gasoline in the days before catalytic converters became standard.

Now, France is paying for that choice in the form of high levels of harmful particulate matter and other aftereffects of diesel-exhaust emissions from cars that don’t come close to meeting current diesel emission standards.

France has “long favored the diesel engine,” Valls said in his speech, but claimed that it was a “mistake” that must be undone with policy changes that could – in the long term – end diesel’s dominance.

Read more: Green Car Reports