A working delegation involved in implementing Almaty’s Air Protection Rules recently visited Sofia, Bulgaria, to study the city’s experience with Low Emission Zones (LEZs). Sofia was the first city in Eastern Europe to introduce such a zone. Its experience is particularly relevant to Almaty: both cities are located in mountain basins and face winter temperature inversions, large numbers of older vehicles, and air pollution caused by solid-fuel heating in private households.

One of Sofia’s key achievements is an approximately 93% reduction in the number of daily violations recorded within the zone — from around 20,000 vehicles before the LEZ was introduced to 3,700 violations during the first seven days of December 2024, and then to 1,350 by February 2026. This happened even before fines were fully enforced, as the city introduced automated violation detection, public information campaigns, and notifications to drivers.

The visit was initiated by the Almaty Air Initiative (AAI). The delegation included representatives of the foundation, Eco Almaty LLP, Almaty Parking — the operator of Almaty’s Low Emission Zone (LEZ) — and members of the working group responsible for developing and implementing Almaty’s Air Protection Rules. The delegation met with Sofia Mayor Vasil Terziev, relevant municipal departments, a city council member, district administration officials, a representative of a medical association, and independent experts. This range of stakeholders allowed the delegation to gain insight into the practical challenges of implementing such zones.

Following the visit, Almaty Air Initiative prepared an analytical report on Sofia’s Low Emission Zone and how its experience could be applied in Almaty. The Bulgarian capital’s experience demonstrates that the effectiveness of such measures depends not on the strictness of restrictions alone, but on the readiness of the entire urban system: data quality, available transport alternatives, clear rules, social support, and effective enforcement mechanisms.

Key Lessons from Sofia

Driver behavior can change even before fines are enforced

Sofia introduced restrictions gradually, starting with a small area in the historic city center and targeting only the most polluting vehicle categories. Major roads along the zone’s boundaries remained open to through traffic, while an alternative route was expanded and equipped with a dedicated public transport lane. Before the restrictions were introduced, approximately 20,000 vehicles in the lowest environmental category traveled through the future zone each day. During the first seven days of LEZ operation, from December 1 to 7, 2024, an average of around 3,700 violations were recorded daily. By February 2026, this figure had fallen to approximately 1,300–1,400 per day — a 93% reduction compared with the period before the restrictions. This happened even before fines were fully enforced, supported by driver information campaigns, automated violation detection, and notifications.

Restrictions must be accompanied by social support

Sofia combined restrictions on coal and wood burning with a free heating equipment replacement program. By early 2026, approximately 20,000 heating devices had been replaced in around 11,000 households. Residents who have applied for replacement equipment and are awaiting installation are exempt from penalties. This experience demonstrates that environmental policies do not necessarily have to increase inequality.

Enforcement systems must be ready before penalties are introduced

In Sofia, violations are detected by cameras, but enforcement is complicated by fragmented databases, lengthy administrative procedures, and the requirement to deliver paper notifications. As a result, the effectiveness of the zone depends less on the size of fines than on a fully integrated digital process — from detecting violations to issuing notifications and processing payments.

Impact must be measured from day one

There are no official air quality monitoring stations inside Sofia’s LEZ, making it difficult for the city to distinguish the zone’s impact from weather conditions and other factors. AAI experts therefore recommend that Almaty conduct baseline measurements in advance, synchronize traffic flow and air quality data, and establish an independent impact evaluation process.

Zhuldyz Saulebekova, Executive Director of Almaty Air Initiative:

“It was important for us to learn from a city that had gone through this process relatively recently, while the challenges were still fresh in people’s minds. That is why we spoke directly with those who designed, launched, and now administer Sofia’s LEZ: what worked, where they encountered problems, and what they would do differently today. These are the kinds of insights that rarely make it into official reports, yet they are especially valuable for Almaty, which is only beginning this journey.”

Aidana Kassen, Deputy General Director of Eco Almaty:

“Sofia’s experience has shown that environmental restrictions are