Restricting the oldest vehicle groups would have immediate benefits in Gliwice, Poland, a new TRUE modeling study finds
A low-emission zone (LEZ) in Poland’s most industrialized region could result in a 28% reduction in NOx emissions and up to 43% in PM emissions within the first phase while impacting a small portion of the fleet.
Expanding upon previous TRUE work in the city of Warsaw, new analysis was conducted in the Silesia region of Poland to identify the potential benefits of a low-emission zone in the city of Gliwice.
The Silesia region in Poland, where Gliwice is one of the main urban centers, faces considerable air quality issues. As the most industrialized region in Poland, excess levels of particulate matter (PM) and nitrogen dioxide (NO2) are associated with increased respiratory diseases, including asthma, in children and adults.
Analysis conducted by TRUE partner the International Council on Clean Transportation identified the potential vehicle emissions reductions that could be achieved by implementing an LEZ in Gliwice between 2026 and 2035 based on real-world data of fleet activity and emissions. In consultation with the city, fleet data was provided by the city using measurements from an Automatic License Plate Recognition camera.
In the proposed LEZ design, starting in early 2026, only diesel cars certified to below Euro 4 (<= 20 years) and petrol cars certified to below Euro 3 (<=25 years) would be restricted from entering the LEZ. Restrictions would become progressively more stringent every 3 years until 2035, when only diesel cars certified to Euro 6d and above, and petrol cars certified to Euro 6 and above, would be permitted in the zone.
Immediate benefits would be realized by restricting the oldest, highest-emitting vehicle groups. By the end of the first proposed phase in 2026, the LEZ could achieve a 21%–28% reduction in fleet-average nitrogen oxide (NOx) emissions and a 37%–43% reduction in fleet-average PM emissions while impacting only about 8% of the passenger car fleet.
Through Phase 2, the LEZ could achieve a 75% reduction in average PM emissions compared with 2025 levels, 7-8 years earlier than the scenario without an LEZ. This is largely due to the phaseout of pre-Euro 5 diesel vehicles that are not equipped with diesel particulate filters (DPFs). It will become important from the implementation of the second phase in 2029 to also detect diesel vehicles with malfunctioning or removed DPFs that require repair. This could be accomplished through particle number testing as part of periodic technical inspection.
The modeling of prospective emission benefits also considers potential vehicle owner responses to the implementation of an LEZ. This ranges from purchasing used compliant vehicles and upgrading to new compliant vehicles, to switching entirely to zero-emission alternatives. Regardless of scenario, the emission benefits of an LEZ would be substantial, but a transition to zero-emission alternatives, like battery-electric vehicles or cycling, could accelerate a 75% reduction in NOx emissions by 7 years, and PM emissions by 8 years, compared to a scenario with no LEZ.
A low-emission zone in Gliwice would not be the first for Poland. Supported by TRUE analysis and modeling of different LEZ scenarios, Krakow introduced an LEZ in March 2023, and in June of this year, Warsaw also launched an LEZ targeting the highest emitting vehicles. As cities explore the benefits and implementation of potential LEZs, uncertainty and responses from concerned citizens has proved challenging, as seen in the current suspension of the Krakow zone. But in recent months, public consensus surrounding the measures has trended upward. An effective LEZ design should maximize emission impacts while minimizing the burden on vehicle owners.
“As PSNM (New Mobility Association), we are actively supporting several LEZ projects across Poland, each designed to address local challenges and improve environmental outcomes,” says Agata Wiśniewska-Mazur, Associate Director of Organization Development at PSNM. “The potential benefits of an LEZ in Gliwice are significant, offering a clear pathway to cleaner air, better health, and a more sustainable future. Our Local Government Committee serves as a vital discussion forum in this field, ensuring that these efforts are grounded in community needs and that all relevant stakeholders are involved. By working closely with cities like Gliwice, we aim to tailor LEZ solutions that not only meet emissions targets but also support the long-term vision for sustainable urban mobility.”
“The FIA Foundation is encouraged by the growing body of evidence from Polish cities showing that low-emission zones can deliver meaningful improvements in air quality by focusing on a relatively few grossly emitting vehicles,” says Sheila Watson, Deputy Director of the FIA Foundation, a TRUE Partner and the core founder. “The modeling from Gliwice, using TRUE data, builds on the success seen in cities like Krakow and Warsaw, and shows other cities in Poland, and across the region, one key way of working towards healthier environments and sustainable urban mobility solutions."
