Beginning December 1 and lasting until February 28, Sofia's city center will prohibit all vehicles classified in the first and second eco groups. This ban applies to the area known as the "small ring," which is bordered by "Vasil Levski," "Patriarch Evtimii," "Skobelev," "Oplchenska," and "Slivnitsa," as announced by the Sofia Municipality.

This year marks an expansion of the restrictions, as last year's ban was limited only to vehicles in the first eco group. Approximately 140,000 of the most polluting vehicles are expected to be affected by this new traffic regulation.

Additionally, from January 1, residents in several metropolitan neighborhoods, including "Sredets," "Triaditsa," "Lozenets," "Krasno selo," "Izgrev," "Ilinden," "Studentski," "Oborishte," and "Vazrazhdane," will be prohibited from using fireplaces. This ban on heating with coal or wood is anticipated to impact around 1,700 households. Violators who use their chimneys in these areas may incur fines ranging from 50 to 200 leva.

The first eco group includes vehicles with two-stroke engines not subject to emissions testing. This category covers cars up to eight seats and weighing up to 3.5 tons, including light trucks and vans. It comprises gasoline-powered vehicles without an environmental category manufactured before July 1, 1992, emitting up to 4.5% carbon monoxide while idling. Additionally, it includes Euro 1 and Euro 2 vehicles produced before January 1, 1996, emitting up to 3.5% carbon monoxide when idling, as well as diesel vehicles from Euro 1 to Euro 4 manufactured before January 1, 2002, with specific smoke emission levels.

The restricted access applies specifically to the "Small Ring" area. Starting December 1, 2024, similar restrictions will extend to vehicles classified in the second eco group. This category includes gasoline-powered cars and vans from Euro 1 to Euro 3, produced before January 1, 1998, and diesel vehicles from Euro 2 to Euro 5 manufactured before January 1, 2007, with regulated smoke levels.

Residents with a permanent address within low-emission zones who possess a paid parking sticker from the Center for Urban Mobility will be exempt from the ban.