An environmental zone is a specific area in a city or region that is protected by regulations and restrictions to improve air quality. These zones are usually established to reduce emissions of pollutants such as nitrogen oxides and particulate matter, which are responsible for poor air quality in many cities.

In these zones, certain rules apply to vehicle access based on vehicle emissions. This may include imposing driving bans on certain types of vehicles, such as older diesel vehicles, or requiring the creation of an eco-label for vehicles. This mark, which must be affixed to the vehicle, confirms that the vehicle complies with the applicable emission regulations and is therefore authorized to drive in the low emission zone.

The introduction of low emission zones has led to a significant improvement in air quality in many cities. It has been observed that emissions of nitrogen oxides and particulate matter have been reduced in these zones, thereby improving the health of residents. The number of respiratory diseases and cardiovascular diseases also decreased.

However, it is not just the introduction of environmental zones alone that can lead to an improvement in air quality. It is necessary to take other measures to reduce emissions overall. These include, for example, promoting electromobility, increasing energy efficiency and creating alternative means of transportation such as bicycles and public transportation.

Environmental zones are an important tool to improve air quality in cities and regions and reduce the impact of air pollution on the health of residents. They are used in many European countries and have shown to have a positive effect on air quality.

Environmental zones are also known in other countries as Environmental Zones, Clean Air Zones (England), Miljøzone (Denmark), Miljözon (Sweden), Lavutslippssone (Norway), Alacsony Kibocsátási Övezet (Hungary), Zona ambientale (Italy), Umweltzonen (Germany), Milieuzones (Netherlands), ZFE - Zone à Faibles Émissions (France) and Lage-emissiezone (Belgium), ZBE - Zona de baixes emissiones (Spain).

Winter zone: There are environmental zones which are only seasonally active or have stricter rules for certain months. This means that these zones are active, for example, from September 15 to April 15 of the following year. Outside of this time, no or less strict driving restrictions apply and you can drive freely. One country with many winter zones is Italy. 

A ZTL (Italian: Zona a Traffico Limitato) is a specific area in a city or region where vehicle access is restricted or limited in order to reduce traffic and emissions. These zones are often established in historic centers of cities or in residential areas to improve the quality of life for residents and reduce noise and exhaust pollution.

In a ZTL, for example, there may be bans on driving certain types of vehicles, such as older diesel vehicles, or restrictions on access at certain times of day. It may also be necessary to have a special permit or parking pass to drive in these zones.

Access to a ZTL is usually controlled via electronic monitoring systems, such as cameras or induction loops. Vehicle owners who violate the rules risk heavy fines.

The introduction of ZTLs has led to a reduction in traffic volumes in many cities.