Low-emission zone

A low-emission zone (LEZ) is an area where the most polluting vehicles are charged a fee to enter — or banned outright — to clean up the air people breathe. Which vehicles count usually depends on their emissions standard (in Europe, the Euro rating) rather than age directly, so an old but clean vehicle can qualify while a newer dirty one pays.

Hundreds of European cities now run some form of LEZ. London's Ultra Low Emission Zone is the flagship: it charges non-compliant vehicles £12.50 a day, expanded to cover all London boroughs in 2023, and is enforced around the clock by number-plate cameras — the very same camera network first built for the city's congestion charge two decades earlier. Transport for London estimates it cut roadside nitrogen dioxide across the capital by more than a quarter.

The honest limits: gains shrink once most vehicles already comply, so late expansions deliver less than the first zone did. Charges can also hit lower-income drivers who cannot easily replace an older vehicle, which makes scrappage support and early, honest communication essential — and the enforcement cameras carry the same privacy trade-offs as any plate-reading network.