Innovative demand responsive green public transportation for cleaner air in urban environment

SOFIA, Bulgaria


population increase for the last 10 years


of the cars are older than 20 years


of PM2.5 emission produced by old cars


new urban transport services to be introduced resulting in PM and CO2 reduction

€ 3,712,55352


About the project —

Air pollution in Sofia goes way back and despite recent positive developments, the city is still struggling and exceeding the minimum thresholds. This is a complex problem. While some factors – like the geographical location in a plateau surrounded by high mountains causing winter thermal inversions – are beyond human control, other causes are linked to human activity. The city is growing fast in terms of population and new residential and office districts. The number of vehicles registered in Sofia raises daily. There are 550-600 cars per 1,000 inhabitants. Bulgarians drive some of the oldest cars in the EU: in 2017, one-fourth of all vehicles were older than 20 years and an additional 60% – between 10 and 20 years. Traffic in Sofia has the highest impact in terms of pollution of ambient air.

The INNOAIR project is co-financed by the European Regional Development Fund through the Urban Innovative Actions Initiative.

Sofia is taking ambitious steps to electrify and expand public transport options. The city will launch “On-demand green public transport”, which will shift the way public transport works. Instead of driving on pre-defined routes, the new e-buses will create a route map based on citizen demand submitted via mobile application. The app will leverage machine learning and advanced data analytics to create the most efficient path for each ride, collecting as many passengers as possible. This innovative public transport service will be implemented together with a wide array of initiatives: low emission zones, green corridors, congestion charge, promotion of active mobility. This coordinated effort of Sofia shall reduce pollution and protect the air we share, while also modernizing and innovating our public transport.

INNOAIR introduces transformational innovation in the form of "On-demand green public transportation", which will revolutionize urban mobility in Sofia. The project delivers a set of tools that will reduce single-vehicle drives and improve air quality in the city. Upon completion of INNOAIR the city will have a pool of coordinated policy tools, including:

- "On-demand green public transportation", formed by a platform with machine learning and advanced analytic capabilities and mini electric busses;
- Congestion charge model;
- Low Emission geospatial urban zones, preventing vehicles from entering the city center and certain areas on polluted days;
- Green corridors for active transport.

The project will result in significant behavioral change and broader use of public and active transport. PM and CO2 emissions will be reduced, contributing to the improved quality of air and citizen health.

October 2021: Digital tool with incentives for switching to public transport or active transport released.
December 2021: Low emission geospatial zones mapped and tested.
October 2022: Green corridors for active transport mapped.
February 2023: Congestion charge model developed.
May 2023: A series of 12 “Beat Air Pollution” citizen challenges delivered.
June 2023: On-demand green transportation established.