The LEZ represent a policy under which an area of a city, usually the most congested, is designated for use only by vehicles which emit low levels of air pollutants, particularly fine particulate matter (PM) and nitrogen dioxide.  The restrictions on high emission vehicles helps to improve air quality, reduce vehicle congestion, raise revenue, and further climate action.

Under the LEZ, or similar Zero Emission Zones (ZEZ), the level of emissions determines which vehicles are permitted in the area.  High emission vehicles are either banned from the area or charged a fee to enter the area.  The fee serves as a disincentive for traffic in the area, and often provides financing for climate actions.  In contrast a “congestion zone” focuses on limiting the number of vehicles, without any requirement for levels of emissions.

Such LEZ or similar road pricing schemes have been developing since 1975 and currently Europe leads the world in LEZs, with more than 250.

Some further ideas to explore on LEZ:

What are the benefits and detriments of low emission zones in comparison with “no emission zones?”

Which pollutants are reduced by implementing a LEZ in a congested area of a city?

Does a LEZ differentially impact low income versus high income households?

Sources:

David Reichmuth and Coreen Weintraub, “Low- and Zero-Emissions Zones:  Opportunities and Challenges in Designing Equitable Transportation Policies,” Union of Concerned Scientists (17 June 2021).  bit.ly/383Iwfx

Transport & Environment, Low-Emission Zones are a success – but they must now move to zero-emission mobility (September 2019).  bit.ly/3guMx1g

Transport for London, Low Emission Zone bit.ly/2WiKh5Z