Criticized by some and cherished by others, the low-emission zone (LEZ) in Brussels is having the desired effect, according to the annual evaluation by Brussels Environment.
The LEZ is leading to faster fleet renewal and better air quality in the Brussels-Capital Region. An average of 360,000 unique vehicles drive in the LEZ every day. Just over half of these (50.9%) are registered in the Region, 38.2% in Flanders, and 10.9% in Wallonia.
Sharp decline in pollutants
Between 2018 and 2024, the concentration of nitrogen oxides (NOx), a significant form of particulate matter, fell by more than 55% for an equivalent traffic volume. Particulate matter fell by 33% and black carbon concentration by 62%. Nitrogen concentration along busier traffic routes decreased by 45%.
The composition of the vehicle fleet is also undergoing significant changes due to the introduction of the LEZ in the Brussels-Capital Region. By early 2025, the Brussels vehicle fleet is expected to consist of 69% gasoline-powered, 23% diesel-powered, and 8% fully electric vehicles. Electrification mainly takes place in company vehicles (27% of Belgian registrations in 2024), while only 1,22% of private cars are electric.
More charging stations and European regulations, such as the ban on the sale of combustion engines from 2025, if that measure is upheld now that Germany, among others, is openly questioning it, should accelerate this evolution. For your information, the Region currently has 9,500 charging points accessible to the public.
Stricter enforcement, but tolerance first
In Brussels, the LEZ will be tightened from January 1, meaning that Euro 5 diesel vehicles and Euro 2 gasoline vehicles, among others, will no longer be allowed to drive within the Brussels Region. This category represents approximately 8% of the vehicle fleet, i.e., 240,000 vehicles. Of these, 29,000 are registered in the Region itself. “The vehicles that will be banned in the final phase are responsible for more than 40% of NOx emissions from transport in Brussels,” according to Brussels Environment.
This tightening of the rules in the Brussels-Capital Region had initially been postponed. Still, because the Constitutional Court suspended the ordinance relating to the LEZ postponement for two years, they will now come into effect as originally intended.
However, the outgoing Brussels government has decided to be lenient. From January 1, 2026, motorists who break the rules will first receive a warning letter. They will then have three months to comply: the first fine of €350 will only be sent three months after the first violation. Owners who can prove that they have a purchase order for a new compliant vehicle, dated no later than December 31, 2025, will also be exempt from a fine.
In 2024, 16,157 fines were issued, compared to 27,212 in 2023. And 1,402 Brussel’Air allowances were granted. In the form of a mobility budget,
The allowance gives access to various mobility options: a budget for bicycles, shared bicycles, shared cars, taxis, public transport, and so on.
It is also important to note that, according to Brussels Environment, the share of vehicles concerned did not decrease further once the postponement of the 2025 milestone was announced, contrary to what was observed at the time of the 2022 milestone.
This illustrates the tangible effect of the LEZ on the vehicle fleet, showing that changes in regulations have a direct impact on the presence of polluting vehicles in the fleet circulating in Brussels.
Pollution remains a significant problem
In Flanders, more specifically in Antwerp and Ghent, the tightening of the rules has been scrapped. However, the decision still must be approved by the relevant advisory councils and the Council of State, so it could still be suspended in Flanders.
Brussels Environment also notes that, despite these positive developments and the results of the LEZ, air pollution remains a significant issue for Belgium, Brussels, and its inhabitants.
In 2024, it caused more than 4,000 premature deaths in Belgium, mainly due to exposure to particulate matter, nitrogen dioxide, and ozone: 4,102 because of exposure to particulate matter (PM2.5), 1,264 due to exposure to nitrogen dioxide (NO2), and 2,570 due to exposure to ozone (O3).
In the Brussels-Capital Region, exposure to PM2.5, NO2, and O3 is estimated to have caused 298, 144, and 175 premature deaths, respectively, in 2024.
“Although Brussels largely complies with current European standards, further efforts are needed to meet the stricter targets for 2030 and the recommendations of the World Health Organization,” Brussels Environment concludes.
