Author: Lidiya Vitanova, Klimateka
Traffic is a daily challenge for residents of large Bulgarian cities. Travel time is the result of many factors, such as road infrastructure, speed limits, traffic and congestion.
In recent decades, Sofia has faced a number of problems - heavy traffic, air pollution and rising temperatures. The main reason for this is the growing number of private cars. In 2020, there were 663 cars per 1,000 people in the city. This trend highlights the need for alternative forms of transportation and limiting dependence on the private car. In response to these challenges, the Sofia Municipality is taking various measures for sustainable mobility, including expanding the metro and introducing electric buses. The aim of these initiatives is to improve connectivity in the city and reduce carbon emissions.
What are the benefits of improving mobility in Sofia?
Improving mobility in Sofia brings a number of benefits to both citizens and the urban environment. First of all, it leads to a reduction in congestion and ensuring faster, more efficient and predictable travel. With improved traffic flow and less use of private cars, emissions are reduced and air quality improves, which has a direct impact on public health. Increasing road safety is also of key importance - better organized traffic creates a safer environment for pedestrians and cyclists. In addition, good mobility improves access to services, education and jobs, especially for residents of peripheral areas. The use of sustainable forms of transport, such as walking, cycling and public transport, is encouraged. This also leads to economic benefits such as lower transport costs and increased logistical efficiency. Improved mobility also creates opportunities for better urban planning and the distribution of public spaces and the creation of a more attractive, accessible and sustainable urban environment that is better prepared to respond to climate change.
What are the good examples and practices from abroad?
In Bologna, the “Città 30“ policy was introduced in 2024, limiting the speed in the city to 30 km/h, with the aim of increasing safety and quality of life. Studies on the impact of this measure show a significant reduction in average car speeds, especially during peak hours, with a slight increase in travel times and almost no change in overall traffic.
In Marseille and Munich, programs have been introduced that provide advice and combined travel – walking, cycling and public transport. Thanks to these programs, car trips have decreased by between 6 and 12%.
Another example is Copenhagen, where smart traffic lights have been implemented, recognizing and giving priority to cyclists and buses, reducing travel times by up to 20%. Paris is testing special lanes on the ring road designated for shared cars, public transport and taxis during peak hours, with the aim of reducing congestion and pollution.
What is the Sofia Transport Atlas?
The Transport Atlas is a spatial map based on data. It visualizes traffic intensity, the number of cars in certain sections, travel patterns and load zones. The atlas serves as a tool for mobility analysis, helping urban planners to distinguish areas with intensive traffic and propose sustainable solutions. The benefits include a better understanding of traffic, targeting investments in transport infrastructure and developing sustainable transport and climate policies.
The Sofia Transport Atlas shows the areas with the highest load, as well as the hours with the most intense traffic. This allows for better identification of critical congestion areas, as well as determining peak load hours. The information thus obtained supports informed decision-making for urban planning, optimization of transport infrastructure and development of sustainable traffic management policies.
Modern approaches to improving the analysis and visualization of traffic patterns use a variety of data sources. These include GPS and vehicle tracking data, data from mobile applications and sensors, traffic cameras and video analytics, GIS and spatial data, and analysis of traffic surveys. The Sofia Atlas was created by collecting traffic data from private vehicles based on GPS information from TomTom Traffic Stats data. The data was processed using GIS and spatial analysis and represents about 8% of the total traffic related to passenger cars in Sofia.
When is traffic in Sofia the most intense?
On weekdays, peak hours related to daily commuting are clearly visible. Typically, traffic jams are the largest in the morning between 8:00 and 9:00 a.m. and in the evening between 5:00 and 6:00 p.m. (Fig. 1). The results coincide with the pilot sociological study on sustainable transport in Sofia, according to which the busiest morning interval is 8:00-9:00, with a peak between 8:00 and 8:30. In the evening, most people return home between 18:00 and 18:30. Despite these peaks, movement and traffic remain intense for most of the day.
The number of passenger cars does not fall below 75,000 between 8:00 and 18:00.
It is possible that the lack of clearly defined “intermediate” calm periods is a result of the uneven distribution of activities and the limited efficiency of public transport. This continuous car flow may be a prerequisite for low use of public transport, a lack of alternative methods of transport and a habit of using private cars, even for short trips. Data from a representative survey within the framework of the development of the Sustainable Urban Mobility Plan show that almost every second working Sofia resident uses a car to travel to work and back.
On weekends, traffic in Sofia follows a different rhythm - the peak is between 12 and 2 p.m.
The lack of daily trips to work and school leads to a significant reduction in traffic on weekends. In the morning between 8:00 and 9:00 and in the evening between 17:00 and 18:00, people travel less frequently, and traffic is more evenly distributed in the interval between 11:00 and 19:00, with a more pronounced peak between 12:00 and 14:00 (Fig. 2).
Despite the presence of daily peaks on weekends, the maximum number of cars is more than two times lower than on weekdays.
These results are also confirmed by the report on transit traffic in central Sofia, according to which there is no clearly pronounced morning peak on Saturdays and Sundays, and the first significant increase in traffic is observed around 12:00. In addition, during weekends, traffic is influenced by activities such as shopping, walking, etc., which are usually evenly distributed throughout the day. day.
Where are there the most cars in Sofia?
The most intense traffic on weekdays is observed between 5:00 PM and 6:00 PM at the main intersections and boulevards of Sofia, which also coincides with the peak hours when people return from work and school.
On weekends, the peak is between 12:00 PM and 1:00 PM, especially in the central part of the city and around commercial sites, transport hubs or other popular destinations that attract more people and lead to increased traffic.
What are the top locations with the most passing cars in Sofia?
Among the locations with the highest concentration of cars in Sofia (Fig. 4), the Ring Road and Tsarigradsko Shose Blvd. stand out, which are defined as key transport arteries with frequent and serious traffic jams.
Most cars pass by the road junctions and intersections near the Botanical Garden, Blvd. “Cherni Vrah“, Samokovsko Shosse and Kazichene.
These locations coincide with the city's entry and exit points and with places with intensive commercial and logistical traffic. Shopping centers, which are among the top 30 locations in Sofia, can also be highlighted as generators of car traffic. The data confirms that the Ring Road performs a key transport function, but also highlights the need for better traffic management and potential measures to improve mobility in these areas.
How to improve mobility issues?
The study and data highlight 5 main conclusions, each of which is accompanied by relevant recommendations and measures that can be taken to alleviate traffic in Sofia.
Conclusions and recommendations for easing traffic in Sofia
The main cause of traffic in Sofia on weekdays is travel to and from work. The heaviest congestion occurs during peak hours – 08:00-09:00 and 17:00-18:00. The recommendations include encouraging flexible working hours and the possibility of remote working; staggered start times for work and school; improved public transport during peak hours; encouraging alternative forms of transport – walking, cycling and carpooling.
During weekends, drivers in Sofia travel less frequently and at different times of the day, which leads to a more even distribution of traffic, especially between 09:00 and 17:00. A potential measure could be to optimize the public transport schedule in relation to the changed traffic pattern.
In the early hours of weekdays, especially between 03:00 and 04:00, as well as on weekends between 04:00 and 05:00, an increase in the number of passenger cars in the airport area is reported. Recommendations include providing public transport at night or early in the morning; expanding the schedule of existing lines that serve the airport area.
The locations with the highest distribution of passenger cars in the city include the Sofia Ring Road and Tsarigradsko Shose Blvd., which have been identified as the main arteries of serious transport delays. Measures may include proposals for alternative existing or construction of new bypass routes and connecting streets to relieve traffic from the main arteries.
Are there any good initiatives in Bulgaria?
To improve mobility, integrated measures are needed to optimize public and private transport, as well as policies to control car traffic and improve access to transport in peripheral neighborhoods. Below we examine some of the good practices in our country.
Low-emission zones should limit the movement of more polluting cars, especially in sensitive and heavily congested areas of the city. Low-emission zones are introduced with clear rules and standards for the permissible categories of cars, while providing alternative transport options for residents. The concept of creating low-emission zones is embedded in the long-term strategy of Sofia Municipality for improving ambient air quality.
Promoting carpooling and the use of public transport.
The aim is to reduce the number of single-occupant cars and to stimulate more efficient use of resources through carpooling platforms. A good example in this regard is the INNOAIR project, which launched in Sofia in May 2023 and is available in several metropolitan districts, such as Manastirski Livadi. It introduces electric “on-demand” buses that follow schedules and routes based on passengers’ requests in an app, as an alternative to short car journeys.
Expanding the network of buffer parking lots is another measure that could help ease traffic.
As part of a large-scale eco-project, Varna plans to build 4 underground buffer parking lots around the city center. The aim is to limit car traffic in the center and encourage the use of public transport, which will be free in certain areas.
Improving the frequency and accessibility of public transport in remote areas.
To reduce dependence on private cars in the peripheral parts of the city, regular renewal and expansion of routes is necessary, as well as ensuring adequate service frequency during peak hours. In Plovdiv, for example, the city is working on integrated urban transport projects that include renewing the bus fleet and improving the transport infrastructure, with the aim of better serving remote areas.
Investing in cycling infrastructure and safe pedestrian connections.
Stimulating alternative forms of transport requires the construction of a well-planned cycling network connected to key points of the city, as well as providing safe, illuminated and comfortable pedestrian routes. In Sofia, the “Green Ring Sofia” project aims to create a 30-kilometer linear park that connects over 30 neighborhoods through cycling and pedestrian paths, transforming abandoned railway tracks and terrains into green spaces, with the aim of improving mobility and quality of life in the city.
Introducing dynamic traffic management through intelligent systems
such as smart traffic lights, mobile applications, etc. The Municipality of Stara Zagora has built a modern traffic management system, including smart traffic lights and a central control center. The system allows for adaptive traffic management and improves road safety.
Financial incentives for the use of electric and low-emission vehicles.
These measures include tax reductions, subsidies for the purchase of electric vehicles, opportunities for free or preferential parking, as well as charging and access to certain urban areas. One example is the DRIVE-E project, which envisages the installation of 1,400 charging points in 13 European countries, including Bulgaria.
Campaigns to raise awareness of the impact of road traffic on the environment and health.
One example of a campaign is the European Mobility Week. Its aim is to promote sustainable mobility, active transport and the creation of liveable cities.
In conclusion, Bulgarian cities need a comprehensive and coordinated implementation of integrated measures to achieve smart transport. Improving mobility requires a combination of technological innovations, infrastructure investments and behavioral changes, through the implementation of policies and measures aimed at reducing harmful emissions and the negative consequences of climate change.
The article presents the first transport atlas of Sofia, which shows the distribution of cars in the city. The study, conducted at the GATE Institute under the leadership of Dr. Eng. Lidia Vitanova and co-authors Tereza Trendafilova, Evgeniy Shirinyan and Prof. Desislava Petrova-Antonova, introduces a comprehensive approach to the analysis of urban traffic dynamics and the behavior of drivers of private vehicles. The atlas takes into account various spatial and temporal factors in the city. By integrating high-resolution data from TomTom's Traffic Stats platform and using geographic information systems (GIS), an advanced method is being developed that combines different sources – including traffic information, traffic density and energy consumption. This allows for a multi-layered analysis of urban challenges.
GATE Institute is the first center of excellence in Bulgaria, which works to integrate and expand scientific achievements and innovations in priority areas such as big data and artificial intelligence at the regional and European level, led by Prof. Silvia Ilieva.