Trolleybus transportation is undergoing a renaissance as cities across the globe increasingly recognize its value within the context of zero-emission mobility policies.

According to recent statistics, around 22,000 trolleybuses are currently operational in approximately 260 cities worldwide, a number projected to grow significantly in the coming years.

Despite a declining trend in the latter half of the 20th century, when many cities replaced trolleybus systems with diesel buses due to perceived operational simplicity and cost-effectiveness, trolleybuses are now regaining attention as vital components of urban public transport.

The International Public Transport Association (UITP) has noted that trolleybuses operate with zero local emissions, akin to other electrified transport systems, supported by recent advancements in technology such as battery-driven autonomous capabilities and in-motion charging (IMC) solutions, enhancing operational flexibility and deployment.

As of May 2025, UITP's comprehensive report indicates that trolleybus networks are active on six continents, with Europe and the post-Soviet region hosting the largest fleets.

The largest number of trolleybuses is still concentrated in Eurasia, where 11,823 vehicles operate across 128 cities, including significant systems in Russia, Ukraine, Belarus, and Central Asia.

European countries, including EU member states, Switzerland, and Norway, now operate 85 active trolleybus networks, boasting a total of 5,390 vehicles over 5,700 kilometers of routes.

Cities such as Prague, Zurich, Gdynia, Rome, Milan, Genoa, Nancy, Esslingen, La Chaux-de-Fonds, and Budapest are at the forefront of this renewed interest.

In the Asia-Pacific region, countries like China, North Korea, and Mongolia maintain 3,086 trolleybuses across 27 cities, covering 2,635 kilometers of track.

Meanwhile, Latin America hosts 1,029 vehicles operating on 1,820 kilometers of networks, with ongoing integration into modern electric Bus Rapid Transit (eBRT) systems.

In North America, only 797 trolleybuses are active, serving networks in Vancouver, San Francisco, and Seattle.

The global trolleybus fleet has seen significant developments, most notably in Beijing, which has the largest individual fleet worldwide, operating 1,044 trolleybuses across 31 lines.

Russia continues to lead in trolleybus operation, with the highest fleet numbers, particularly in Saint Petersburg, which has a fleet of 759 vehicles.

Ukraine follows with 2,479 trolleybuses across 35 cities.

The European Union also features some of the largest trolleybus networks, with Vilnius leading at 270 trolleybuses, followed closely by Bucharest (269), Athens (267), Budapest (141), and Milan (130).

In 2024, Europe witnessed a record introduction of 372 new trolleybuses, marking the highest annual figure in fifteen years.

This modern fleet largely consists of battery-equipped vehicles, representing a significant shift towards advanced trolleybus technology.

Urban centers increasingly view trolleybuses not only as a mode of public transport but also as essential elements for electric-based BRT solutions.

For example, Mexico City has established a specific trolleybus-based eBRT line, with ongoing expansion plans indicating a strong commitment to this infrastructure model.

Additionally, both current upgrades and future procurement plans signal long-term commitments from numerous operators across Europe.

A survey of ten European transport providers indicates that average trolleybus fleet sizes could increase by 120 percent by 2030 compared to 2022 levels.

Budapest’s trolleybus system, which is the largest in Hungary, spans 111.8 kilometers with 141 operational vehicles during peak times.

The average speed recorded is 14.6 kilometers per hour, increasing to 16.4 during busy hours.

Operators, numbering 385, include 290 drivers who complete an extensive 127-day training program, one of the most comprehensive training regimens observed among the networks analyzed.

As trolleybus systems modernize and integrate into broader transport strategies, UITP highlights an evolving role for trolleybuses within urban mobility systems.

The resurgence of trolleybuses reflects a shift in global transportation policies emphasizing sustainability and zero-emission objectives.