Low Emission Zones (LEZs) are one of the many types of access restriction schemes.
LEZs consist of area licensing or entry permits schemes that are applied to restrict the access to specific areas, mainly to city centres. In most cases, the Euro emission categories are used to determine which vehicles may enter the zone.
Compared to other types of access restrictions, low emission zones tend to be simpler to understand and straightforward to implement. They can also be implementedalongside to road charging schemes, as in London, which has a congestion charging zone inside a larger low emission zone.
As with any other access restriction schemes, low emission zones have the potential to be effective in reducing pollution. However, care must be taken to assess details of the scheme and how it is put into practice. Each LEZ scheme should be assessed on a case‐by‐case basis, in accordance with certain criteria, to establish whether or not it is effective and acceptable.