Since 15 January 2020, it is forbidden to drive older cars that emit too much exhaust gas on Hornsgatan.

Environmental zone class 2 was then introduced to reduce the level of dangerous exhaust gases in the area.

But very few have been fined for driving illegally in the zone.

- Many confuse the rules for the environmental zone with the studded tire ban, says Fredrik Ehrström, external commander at Södermalmspolisen.

Little effect on air quality

The air on Hornsgatan is now the cleanest in 30 years.

But the environmental zone has so far had little effect on air quality.

- It has reduced exhaust emissions by approximately two percent.

If the rules had been followed, the reduction would have been around ten percent, says Lars Burman of Stockholm's environmental management.

Environmental zone class 3 will be introduced in 2024

Hornsgatan is the only stretch of road in Sweden that has environmental zone class 2. In 2024, the even stricter environmental zone class 3 will be introduced in the Old Town and certain other parts of the inner city.

- Every year, around 1,000 Stockholmers die prematurely because of the bad air, says climate and environment councilor Åsa Lindhagen (MP).

Hear more in the clip above.