From December 1, 2023, until February 28, 2024, a low-emission zone will be implemented in central Sofia in the so-called "small ring", reported BNR’s Radio Sofia. At intersections where one enters the small ring, there must be signs in Bulgarian and English. The low-emission zone restricts access to vehicles classified within the I eco group.

 The aim is to improve air quality in the central part of the city, which is also the busiest pedestrian area. Cameras will be used to monitor violators. The fine ranges from EUR 25 to EUR 250. Exceptions include residents within the zone and people with disabilities. The restrictions will be in effect for the three winter months-from December 1 until February 28 next year. The scope of the low-emission zone is expected to expand in 2025. Cars are the second-biggest polluter after domestic heating.