Guidebook on air pollution interdependencies for various stakeholders

The guidebook, prepared by the National Institute of Meteorology and Hydrology (NIMH) and Sofia Development Association, is a free tool for policy, research, education, industry and environmental bodies to understand the processes leading to undesired high levels of pollution in urban areas.

Best practice analysis on common global initiatives

This document, prepared by the National Association of Municipalities in the Republic of Bulgaria (NAMRB), contains a review of the trends in mobility solutions, related to the main innovation of INNOAIR, namely on-demand transport (with electric minibuses) combined with “mobility as a service” like technologies, low emission zones and congestion charging model.

Multi-stakeholder dialogue on air pollution interdependencies report

Air pollution in Sofia has long been a problem and despite recent positive developments, the city is still struggling to overcome this complex challenge. Air quality measures are interrelated and finding out how they affect each other will help optimize them faster.

Developing ideas for stimuli for citizens to switch to sustainable transportation - Co-creation Workshop Report

The transition to the use of urban and sustainable transport is a task that requires motivation not only from the institutions, but also from citizens and the business sector. In this regard, the Sofia Development Association, in partnership with Sofia Municipality, organized a co-creation design workshop on developing ideas for stimuli for citizens to switch to sustainable transportation with the participation of over 30 young and active citizens, business representatives and local institutions. The report presents the generated ideas and proposals, as well as the existing incentives.


А guide providing ideas and suggestions for empowerment to local authorities, universities and businesses how to lead the way for a local community that cares. The examples are based on participatory research and co-design process in Sofia.

Passenger behavior analysis

Passenger behavior analysis may be carried out from a different perspective, depending on the final goals and the available data. In this report we only cover some of the available options, focusing on those of them that are relevant for achieving the goals of INNOAIR project.

Modelling of traffic conjunction data and air pollution

Monitoring the concentrations of different compounds in the air over a period of time at different sites, archiving and assuring the quality of these data and their statistical analysis form the basis for air quality assessment in urban areas. The design of a particular air quality monitoring network is a complex task, that takes into account the objectives of the measurements (e.g. for policy development, for public information, for protection of vegetation, for identification of pollution sources etc.).

Benefit Dependency Network on "Green measures to tackle air pollution and climate change"

Benefit Dependency Network (BDN) is a schematic summary of the motives and benefits of a project. For the construction of a logical causal chain of program results, system vision, as well as for their visual presentation, a map of the benefits is needed. This map shows the composition and relationship between the different results of the program: project motivation, project implementation, changes, operational results, and benefits. This is a tool used in decision-making, focusing on benefits and their contribution to the strategic objectives.

Development of possible scenarios on cultural shift in transportation on air quality

The goal of this document is to consider and present scenarios for changes in the air quality caused by a potential reduction of non-environmentally friendly transport. The study focuses on the particulate matter with diameter < 10 μm (PM10).

WHITE BOOK on the introduction and effective operation of low-emission zones for motor vehicles on the territory of the Sofia Municipality

This document is a detailed analysis of the reasons, technology and results of a simulation of pilot testing of the introduction of low emission zones in Sofia.

First 6 citizen challenges conducted

The student competitions are aligned with the project's activities and give students from several universities the opportunity to put into practice what they have learned and show their talent by proposing solutions for a more sustainable and green future. The competitions offer young people the opportunity to give life to their ideas to change the environment.

Green Corridors Route Mapping Analysis

Green corridors presented on a web-based map allow citizens to choose travel options in the city with 0 emissions.

Data analytics modelling of traffic
conjunction and air pollution

NIMH developed several data analytics models to forecast 48 hours ahead average hourly concentrations of nitrogen dioxide (NO2), tropospheric ozone (O3) and particulate matter (PM10) using data collected by the ExEA monitoring urban stations located at Hipodruma and Pavlovoin Sofia for the period 01.01.2019-07.05.2021. The models are hybrid between numerical weather prediction (WRF) model and stochastic models.

District based public transportation scheme
enhancement for air quality reinforcement

The document presents the functionality and results of a newly developed analytical software that monitors line loads, delays and speeds, average speed and provides suggestions for optimization of schedules.

First series of advanced urbansimulations based on modelling & ODPTP

Cloud-based simulations assessing different variables and correlations such as traffic density, holidays, seasonality, etc., related to transport on demand.

Second series of advanced urban simulations based on modelling& ODPTP

Cloud-based simulations assessing different variables and correlations such as traffic density, holidays, seasonality, etc., related to transport on demand.

Report on advanced urban simulations based on modelling and ODPTP

A report with recommendations and formulated hypotheses as a result of 6-month cloud-based simulations and on-demand urban transport modelling.

Second 6 citizen challenges

Six citizen challenges engaging different groups – cyclists, citizens of the area served by on-demand transport, car owners, etc., to work together with designers to create communication materials on INNOAIR.

Twelve citizen challenges

In order to empower and engage citizens, INNOAIR organizes 12 citizen challenges. The report presents their results and assesses the effect of this approach with recommendations.

Background concentrations of key pollutants for the district of interest

Background concentrations of pollutants that are due from sources outside an area of interest but are transferred from atmospheric processes are an important element in assessing the performance of low emission and transport areas on demand. The report presents this assessment.

Development of possible scenarios on cultural shift in transportation on air quality

The report presents scenarios for the effect on air quality of limiting non-ecological transport, with a focus on particulate matter (PM10).

Effect of cultural shift in transport on air quality

The report assesses the effect of low emission zones on ambient air quality.

Effect of green on demand public transport on black carbon concentrations in PMs

The report presents the results of the measurement and analysis of black carbon concentrations in the area of interest in correlation with meteorological parameters such as temperature, humidity and wind speed.

Final evaluation, transferability andlessons learned of “Green, on-demand public transportation”

The document presents the results of the pilot phase of transport on demand, introduced in Manastirski Livadi under the INNOAIR project.

Analysis and roadmap for the introduc tion of "Sofia Congestion Charge Zone”

The analysis presents European experience in the congestion charging, regulations, payment methods and fee amounts, and a roadmap and proposals for changes in the regulatory framework.

Preparation of analyzes and formulation of proposals for
a charging model when implementing measures to improve
the quality of atmospheric air

Statistical analysis, scenarios and mathematical model for the eventual introduction of a congestion charge in Sofia.

Final evaluation report on "Sofia Congestion Charge Zone”

Charging models for the introduction of congestion charge, developed on the basis of statistical analysis and conducted a study on the degree of readiness of citizens to pay a fee.

Final Monitoring and Evaluation Report

The report describes and evaluates the outputs and results of the project, achieving the indicators, success factors, lessons learned and opportunities for transferring good practices.


First issue of the INNOAIR project newsletter

 In the first edition of the INNOAIR project newsletter, you will find not only information about the key developments in mobility in recent months, but also:
- Results and analysis of a survey on citizens' attitudes towards the transition to active transport.
-  Information on the introduction of low-emission zones in the capital.
- Opportunities for involvement in the creation of solutions for innovative urban mobility.

Second issue of the INNOAIR project newsletter

The INNOAIR newsletter updates you on what has happened in the last three months in the field of clean air and sustainable mobility in Sofia: new mobile services, needs and initiatives of people and businesses, R&D, research on human behavior in transport, opportunities to participate in taking decisions.

Third issue of the INNOAIR project newsletter

The INNOAIR newsletter shares with you how we contribute to smarter urban mobility and cleaner air in Sofia. We are happy to present the latest exciting solutions, initiatives and achievements in sustainable mobility in Sofia in the last three months. Stay informed!

Fourth issue of the INNOAIR project newsletter

 With the end of the year approaching, we are happy to inform you on some exciting events and publications that will help you enter 2022 full of inspiration. Not only have we achieved a range of interesting Sofia mobility and air quality developments, but we also started planning the 2022! We would love to hear from our community about your preferences for the second INNOAIR Hackathon so we can plan accordingly and would therefore appreciate your input in our 1-minute hackathon survey

Fifth issue of the INNOAIR project newsletter

 We showcase the latest innovations and news impacting the future of mobility.
Solutions, initiatives, events and achievements that challenge the citizens of Sofia to move more actively and sustainably, thus helping for cleaner air in the capital!
Don't forget that INNOAIR rewards those who use active transport through the SofiaCoin app, available for Android and iOS - it's not too late to join!

Sixth issue of the INNOAIR project newsletter

In this issue of the newsletter we bring to you interesting and innovative for Sofia urban mobility solutions. The introduction of the first in Bulgaria low emission zone is round the corner, as is the innovative service on-demand public transport in three Sofia neighbourhoods, while a live map allows you to see all electric public transport and shared mobility vehicles.
Have a look at the solutions for cleaner air that students developed and implemented in the city. Get to know some of the international INNOAIR partners. Learn more about these and other initiatives and events that help our capital city to breath more easy! 

Seventh issue of the INNOAIR project newsletter

This issue brings to you the latest INNOAIR project developments: we welcomed to Sofia the new electric minibuses, the BUSINN mobile app is ready and soon will be available for download on your phone, the student competitions resulted in the installation of the first cameras to count bicycles in the city and the design brand of the new transport on-demand service. Read more!  

Eight issue of the INNOAIR project newsletter

NNOAIR entered its most exciting phase of rolling out its innovation pilots. Although learning is the primary goal of piloting, the careful design and stakeholder engagement turn them more into high-stakes dress rehearsals. It is not surprising that INNOAIR attracted a lot of international attention by Politico, European Week of Regions and Cities, EUI Applicant seminar and more.

Ninth issue of the INNOAIR project bulletin

Sofia is a finalists for the European Urban Mobility Awards and INNOAIR is instrumental for that achievement! According to the European Commission, Sofia was selected "for its new transportation service that better combines citizens' mobility demands and reduced environmental impact. Services include electric buses, an on-demand mobile application, green corridors and new more affordable tariffs. In addition to providing cleaner and more accessible transport, the Bulgarian capital is working within the framework of the INNOAIR project, which seeks to reduce air pollution through traffic calming measures as part of the European Union’s Urban Innovative Actions.” We invite you to read and learn more in this newsletter.

Final newsletter of the INNOAIR project

The INNOAIR project comes to an end this June after 36 months. Read our final newsletter and learn about our results. We are also happy to bring you insights from our final conference where we were joined by over 100 stakeholders, and the INNOAIR transfer seminars. We thank you for following our progress and we hope that the INNOAIR results will continue to be a valuable contribution to your professional work and active citizenship!


Data driven public transportation delay modelling

The article, published in American Institute of Physics Conference Proceedings (AIP), models delays in public transport, taking into account random factors and events that lead to disproportionately large changes in the schedule.

Mixed data modelling of transportation and incidents

The article, published in American Institute of Physics Conference Proceedings (AIP), analyzes the possibilities for modeling transport systems, using sources of information of different nature, frequency and accuracy.

Big data analytics for modelling consumer preferences and satisfaction in public transportation

The article, published in CSUM2022 (, a model to estimate and analyze consumer preferences and satisfaction from public transportation services is developed. The approach is based on use of big data from multiple sources and allows to achieve continuous and precise estimation of consumer behavior.

AI driven adaptive scheduling for on-demand transportation in smart cities

Artificial intelligence algorithms can be used to automate and improve various processes in public transportation. By using a combination of data sources like positioning devices, ticketing and sales notifications and video surveillance can be obtained details on the load and utilization of transportation network segments. In this paper, published in CSUM2022 (, one such automation system that benefits from delay analysis and real-time processing of video streams is discussed.

Coupled Fixed Points for Hardy–Rogers Type of Maps and Their Applications in the Investigations of Market Equilibrium in Duopoly Markets for Non-Differentiable, Nonlinear Response Functions

In this paper, published in Multidisciplinary Digital Publishing Institute (, is generalized Hardy–Rogers maps in the context of coupled fixed points. It is commented the symmetry of some of the coefficients involved in the Hardy–Rogers condition, and thus, deduced a simpler formula. It is generalized, with the help of the obtained main theorem, some known results about existence and uniqueness of market equilibrium in duopoly markets.

Green Deal in public transportation – transitions that actually make sense

In this paper, published in published in Conference "Economic, Regional and Social Challenges in the Transition Towards a Green Economy" (, it is suggested a generic framework and IT architecture that can facilitate transition path to green public transportation network in an environment-friendly and economically sound way. The solutions developed in the paper are specific, measurable, achievable and time-bound.

Intra City Transport On-demand

A team at Faculty of Economics and Business Administration, Sofia University "St. Kliment Ohridski '' presented an algorithm for optimal trajectories of e-buses fulfiling on-demand requests for transportation in a smart city environment. The article is published in IFAC-PapersOnLine and may be accessed via the link -
The approach demonstrates the possibility of solving a transportation task arising from the introduction of on demand public transportation in Sofia. Instead of solving the transportation problem once, when all transportation requests are registered, we solve the transportation problem at any virtual or public station during the taxi. This approach enables gathering transportation requests dynamically and also considers changes in the environment (e.g. weather conditions, roadblocks, traffic jams, etc) during the transportation. The algorithm is tested with real data.
The realisation of the publication is possible as a result of the pilot introduction of public transport on demand within the city of Sofia under the INNOAIR project financed under the Urban Innovative Actions program. 

Predicting Travel Times for On-demand Public Transport in Sofia

Within the "INNOAIR" project, a team of the Faculty of Economics and Business Administration, published a scientific article examining the approach to predict travel time for on-demand public transport. The authors Angel Marchev, Boyan Lomev and Kaloyan Haralampiev present four predictive models, each of which is tested with data from specific scenarios. The procedure for implementing the prediction model goes through three main phases: model identification, parameter estimation/optimization, and prediction with their respective subphases. Within their work, the researchers chose to use the following models to forecast the target data: Seasonal autoregressive moving average models with exogenous input with Fourier terms; Vector autoregression and vector error correction models; Bayesian Fourier model; Backpropagation neural network models. Root-mean-squared error, measured in seconds, calculated on the test set forecast (the last week of observations) is used to compare the proposed models.
The full text of the article may be accessed on the following link -  

Prediction of the Air Pollution by Geo-locations in Sofia

A team of the Faculty of Economics and Business Administration published a scientific article examining the forecasting of air pollution by geolocation in Sofia
The authors Boryana Bogdanova, Angel Marchev, Vladimir Zakov, Denis Stefannov and Kiril Genov published a paper in IFAC-PapersOnLine presenting a general framework for analysis and forecasting of air pollution in the city of Sofia. For the purposes of their work, the authors use the air pollution indicator particulate matter - PM10, which is among the most frequently exceeded in the metropolitan city. Stepping on existing scientific publications and data provided by air quality stations of Sofia Municipality, Executive Agency Environment and the civil network they built a predictive model and introduced a methodological framework.
The published scientific work is realised within the INNOAIR project, whose main goal is to improve the air quality in Sofia, by introducing a combination of complex measures, including public transport on-demand, green corridors, congestion charges and low-emission zones.
The publication is available through the following link -  


The article published at by a team of National Institute of Meteorology and Hydrology, aims to present and discuss background concentrations of key pollutants (PM, NO2, SO2 and ozone) for the city of Sofia for one summer and one winter month of 2021. It discusses the spatial monthly distributions of the key pollutants and the variability across the city and present domain mean concentrations for the two months. The relationship to some meteorological variables (wind speed, temperature, mixing height) is also discussed.

Small Wins through Inducement Prizes: Introducing Challenge-Oriented Regional Prizes

There is an emerging consensus that innovation policies must be geared towards solving societal challenges. The policy complexity of the third generation of innovation policy, however, puts less-developed European regions at risk of being left behind from this novel policy paradigm due to lower institutional and governance capacities. Building on the concept of a small wins strategy that focuses on small-scale and bottom-up initiatives that are guided by a shared mission to address wicked problems, the article’s methodology uses expert interviews, examples of challenge prizes, and desk research to explore whether inducement prizes can potentially engage less-developed regions in third generation innovation policies to address place-based societal challenges through a small wins strategy. The article introduces the concept of a challenge-oriented regional prize as a stepping-stone policy tool to engage less developed regions in third generation innovation policy through a small wins strategy, namely regarding issues of directionality, legitimacy, responsibility, and strategic orientation. The INNOAIR Hackathons served as a case study for this research, authored by Arnault Morisson, Institute of Geography & Centre for Regional Economic Development (CRED), University of Bern, Isabelle Liotard, University Sorbonne Paris Nord, and Valerie Revest, University Jean Moulin, Lyon.
This article belongs to the Special Issue New Approaches to Sustainable Development in Clusters and Regional Innovation Systems, Sustainability 2023, 15(4), 3240; (registering DOI).  

Assessment of air pollution with FDP10 in the city of Sofia under different scenarios of traffic load in predetermined emission zones

In this paper, Anton Petrov from the National Institute of Meteorology and Hydrology measures the pollution contribution of pollution in four designated zones in Sofia in different scenarios, each involving a different concentration of fine dust particles.

Air quality monitoring: A comparison of 3 statistical techniques for data imputation

In order to draw reliable conclusions for any project or initiative, it is very important to have high quality input data. This study presents a method for quality control and filling missing values in air quality observational data. The results of the paper show that this methodology provides high quality data imputation of the recovered missing air pollutants values.

Measurement of the concentration of Black Carbon in Sofia with a
portable aethalometer MA200

In this paper, Georgi Tsekov and Associate Professor Elena Hristova from the National Institute of Meteorology and Hydrology measure the levels of Black Carbon in Sofia’s air and emphasize on its influence on human’s health and the environment.


At the heart of the initiative INNOAIR is the implementation of on-demand public transport which operates in accordance with consumer demand. How would this happen from a technological point of view? The route of the electric buses will be determined by the requests of the citizens submitted through a mobile application, a part of the On-demand Public Transportation Platform (ODPTP). How does the platform work? See its demo version HERE.

INNOAIR CHALLENGE: Making urban mobility smarter PODCAST, hosted by Gereon Meyer (UIA Expert)

This podcast, hosted by Gereon Meyer (UIA expert) will give you an overview of the hackathon InnoAirChallenge: Making urban mobility smarter.
The hackathon is organized by Sofia Development Association and A1 Bulgaria and it was held online in the period 2-4 June 2021. 24 teams from 7 cities took part in a race for a cause. All participants worked online on the difficult task of developing and presenting projects that outline the vision of a future generation of transport services and connectivity that work for cleaner air in Sofia. Hear out their ideas!
The hackathon InnoAirChallenge: Making urban mobility smarter was the first of a number of hackathons and competitions that Sofia Development Association will organize within the INNOAIR project. 

Artificial Intelligence: Can smarter transit prevent Sofia from car overkill? – INNOAIR podcast, hosted by Gereon Meyer (UIA Expert)

This podcast, hosted by Gereon Meyer (UIA expert), will give you an overview of the opportunities and challenges of using artificial intelligence (AI) in managing sustainable on-demand mobility solutions in Sofia. Learn more about the upcoming emission-free mini buses, how AI is helping this service and what challenges it brings. Hear out what the INNOAIR team is sharing with you!

Sofia Coin – nudging healthier travel behavior for cleaner air

Learn more about the measures that Sofia takes in order to improve the air quality in Sofia. Discover SofiaCoin – the app that rewards the users that move actively around the city and tracks their roads so that Sofia Municipality could renovate them with priority. Hear out about the idea behind its development, the opinion of Sofia Municipality representatives and most importantly – the opinion of its users. The podcast is hosted by Gereon Meyer (UIA expert).