Tram systems in Sofia
Sofia is the capital and largest city of Bulgaria. It lies in the Sofia Valley in the west of the country, beneath Vitosha mountain and close to Bulgaria's borders with Serbia and North Macedonia.
The city developed around the ancient settlement of Serdica and contains Roman remains alongside medieval churches, Ottoman buildings and the monumental civic architecture constructed after Sofia became the Bulgarian capital in 1879. It is the country's principal political, economic, educational and cultural centre.
Sofia Central railway station is the principal hub for domestic and international trains and is served by the city's metro, trams, buses and trolleybuses. The adjoining Central Bus Station provides long-distance services across Bulgaria and to neighbouring countries.
The Sofia Metro opened in 1998 and now consists of four services covering the city centre and many of the outer residential districts. Line M4 serves Vasil Levski Sofia Airport, while the most recent extension of line M3 opened to Stadion Georgi Asparuhov, Vitinya and General Vladimir Vazov on 14 August 2026.
Trams and trolleybuses are operated by Stolichen Elektrotransport, while buses are provided by Stolichen Avtotransport and several contracted operators. Fares, passenger information and integration between the different modes are managed through the Sofia Urban Mobility Centre.
Sofia has an extensive electrically operated tram network owned by Sofia Municipality. Most of the system uses its distinctive 1,009 mm narrow gauge, while a separate standard-gauge network serves parts of eastern Sofia. The standard-gauge infrastructure is principally used by lines 20, 21, 22 and 23.
Eighteen regular tram lines currently connect the city centre with districts including Knyazhevo, Lyulin, Obelya, Iliantsi, Orlandovtsi, Druzhba, Geo Milev and Manastirski Livadi. The network includes traditional street-running sections in central Sofia, segregated reservations along major boulevards and several connections with the metro and suburban railway network.
Sofia Municipality granted concessions to French and Belgian companies in December 1898 for the construction of an electricity supply and an electric tramway. The first services began on 1 January 1901 under the calendar then used in Bulgaria, corresponding to 14 January in the modern Gregorian calendar.
The original network comprised six routes with approximately 23 kilometres of single track. Twenty-five motor cars and ten trailers served destinations including Knyazhevo, Krasno Selo, Poduyane and the city's railway station. There were initially no fixed stops, and passengers signalled when they wished to board or leave a tram.
The municipality began taking control of the system from the Belgian concessionaire in 1916. The transfer was eventually completed in 1927 with the formation of the municipal Directorate of Trams and Lighting.
The network expanded as Sofia grew during the first half of the twentieth century. Vehicles were initially obtained from manufacturers elsewhere in Europe, but local construction began in 1931 with trailers assembled under the direction of engineer Theodosii Kardalev. The first Bulgarian-built motor cars followed in 1936.
A dedicated tram factory was established at Krasno Selo in 1951. It produced the Republika, Komsomolets and Kosmonavt types before introducing the articulated Sofia tram in 1965. Later developments included the three-section Sofia 70 and Bulgaria 1300 vehicles. Locally manufactured trams became one of the defining features of the network, although production ended after completion of the last T8M-900 cars in the early 1990s.
The post-war network was extended extensively to serve Sofia's expanding residential districts. New depots were constructed, reserved tracks were installed along major roads and imported ČKD Tatra cars progressively supplemented the Bulgarian-built fleet.
Sofia's first standard-gauge tramway opened in 1987 between Geo Milev and Druzhba, forming the origin of the infrastructure now used by line 20. A second standard-gauge corridor, forming much of the present line 22, was completed in 1995.
The new infrastructure created two largely separate tram systems. Most of Sofia's routes retained the unusual 1,009 mm gauge inherited from the original network, while the standard-gauge lines were based at the purpose-built Iskar depot and initially operated with Bulgarian and ČKD Tatra vehicles.
Opening of the Sofia Metro in 1998 changed the role of the tramway. Several routes were shortened, reorganised or withdrawn as the metro expanded, particularly where the two modes served similar corridors.
Trams were removed from the pedestrianised section of Vitosha Boulevard, while the route through Borisova Gradina towards Park Hotel Moskva closed in 2010. The former line 9 infrastructure towards Lozenets was subsequently abandoned, and the final section between the Hemus area and the Spartak swimming complex was removed following changes associated with construction of metro line M3.
Despite these closures, the tramway remained an important part of Sofia's transport system, particularly on corridors not directly served by the metro.
Modernisation accelerated with the introduction of low-floor Pesa Swing trams from 2013. Further vehicles followed in several batches, while second-hand trams acquired from Basel entered service on narrow-gauge routes from 2017.
The principal line 5 corridor along Tsar Boris III Boulevard was comprehensively reconstructed between 2021 and December 2023. Line 15 began operating between Buxton and Hladilnika in May 2024, restoring a direct tram connection between the two districts, while lines 3 and 27 were extended to improve interchange at Sofia Sever railway station.
New and reconstructed tracks forming part of the extension of Rozhen Boulevard opened on 15 December 2025, restoring tram services to Iliantsi and providing connections towards the metro and city centre.
The first phase of a wider route reorganisation followed in May 2026. Line 1 was extended between Ivan Vazov and Zapaden Park, while the new line 13 established a permanent service between Zaharna Fabrika railway station and Vitosha metro station.
Sofia Municipality intends to introduce the remaining elements of its tram network reorganisation by 17 November 2026.
Line 8 is planned to be extended from its present central terminus to Journalist Square, creating a direct route from Lyulin through Alexander Stamboliyski Boulevard and central Sofia. Line 3 will be rerouted towards Orlandovtsi via Struga Street, while a new line 17 will connect Manastirski Livadi with Orlandovtsi.
Timetables on lines 4, 6, 10, 12 and 18 will also be coordinated to provide more even intervals where several routes share the same tracks. Further information is available from Sofia Municipality.
A project has been prepared to extend Copenhagen Boulevard between Samokovsko Shose and Alexander Malinov Boulevard. It includes approximately one kilometre of new tramway and would create a direct tram connection between the Druzhba and Mladost districts.
The scheme remains at the project-development stage, and a confirmed construction or opening timetable has not yet been announced. Further information is available from Sofia Municipality.
Sofia Municipality has begun procurement for the redesign of approximately 430 metres of tramway along General Mikhail Skobelev Boulevard between Hristo Botev Boulevard and the entrance to the National Palace of Culture tunnel.
The tracks would be moved northwards and carried partly on a new reinforced-concrete structure. The project is intended to retain tram operation through the corridor while changing the relationship between the tramway, adjoining roads and residential buildings.
Construction is expected to be undertaken without a prolonged complete closure, although no completion date has been confirmed. Further information is available from Stroitel.
Further tramway projects are being prepared for several corridors. These include rehabilitation of approximately 1.2 kilometres of track along James Bourchier Boulevard, reconstruction of the tramway on Hristo Botev Boulevard and renewal of the remaining infrastructure on Knyaginya Maria Luisa Boulevard.
An outline project has also been completed for renewal of 720 metres of single track in Obelya 2. These projects are at different stages of design, approval and procurement, and reliable opening dates are not yet available. Further information is available from Sofia Municipality.
Stolichen Elektrotransport launched a tender in February 2026 for 40 new fully low-floor, air-conditioned articulated trams for the 1,009 mm network. The contract was estimated at €102.3 million excluding VAT, with delivery required within three years of a contract becoming effective and the necessary financing being secured.
A further procurement for 38 vehicles has also been proposed, potentially producing a total programme of 78 new trams. The programme is intended to replace Sofia's remaining older high-floor vehicles, but its final scale and delivery programme depend upon financing and completion of the procurement processes. Further information is available from SeeNews.