New Travel Time Matrix 2023 and GREENTRAVEL project

Digital Geography Lab presented a new travel time matrix 2023 and a new big project GREENTRAVEL in a seminar held in Think Corner.

Helsinki region travel time matrix was published now for the fourth time. The matrix is an interactive open access dataset that allows investigation of travel times for different travel modes in Helsinki region. Professor Tuuli Toivonen gave an insight to the history of the matrix which was first published already ten years ago in 2013.

Since the first matrix was computed, the technology has improved and enabled the use of new methods. Christoph Fink explained how the new matrix was calculated and showed how it works.  Current accessibility prospects and changes in the regional structures of accessibility in Helsinki region were described by Elias Willberg. We also had two guest speekers, Miikka Haimila and Iiris Karvinen, from the city of Helsinki. Haimila reflected the importance of matrix for the city and its open data activities. Karvinen took the angle of a planner and demonstrated how the matrix has been serving the planning needs of the city.

In the end Tuuli Toivonen presented our new big project GREENTRAVEL which aims to explore the availability and quality of green urban travel environments and their impacts on wellbeing through the prism of urban informatics. We continued the discussions right after the seminar in a GREENTRAVEL workshop where we focused on the role of greenery in urban travel environments and how greenery can be better incorporated in current green infrastructure and travel and mobility planning.

Tuuli Toivonen telling about the history of Travel time matrix
Christoph Fink presenting the details of the new matrix
Elias Willberg showing how the accessibility has changed in Helsinki region during the last ten years
Presenters answering to the questions from the audience

Presentations from the event

Click on the image to open the presentation.



Uusi matka-aikamatriisi 2023 ja GREENTRAVEL-projekti

Digital Geography Lab esitteli uuden pääkaupunkiseudun matka-aika-aineiston 2023 ja juuri käynnistyneen GREENTRAVEL-tutkimushankkeen Tidekulmassa järjestetyssä julkaisutapahtumassa.

Pääkaupunkiseudun matka-aikamatriisi julkaistiin nyt jo neljättä kertaa. Matriisi on avoin paikkatietoaineisto, joka mahdollistaa matka-aikojen vertailun eri kulkutavoilla pääkaupunkiseudulla. Professori Tuuli Toivonen kertoi matriisin historiaa valaisseessa puheenvuorossaan ensimmäisen matriisin julkaisusta kuluneen jo 10 vuotta.

Teknologian kehittyminen ensimmäisten matriisien tuottamisen jälkeen on mahdollistanut uusien menetelmien käytön laskennassa. Christoph Fink esitteli miten uusi matriisi on laskettu ja miten se toimii. Elias Willberg valotti pääkaupunkiseudun nykyistä saavutettavuusmaisemaa sekä muutoksia saavutettavuuden alueellisissa rakenteissa kuluneiden 10 vuoden aikana. Mukana olivat myös vierailevat puhujamme Miikka Haimila ja Iiris Karvinen Helsingin kaupungilta. Haimila kertoi matriisin merkityksestä kaupungille ja sen avoimen datan toiminnalle. Karvinen osoitti suunnittelijan näkökulmasta miten matriisi on palvellut kaupungin suunnittelutarpeita.

Lopuksi Tuuli Toivonen esitteli uuden viisivuotisen GREENTRAVEL-tutkimushankkeen, jossa selvitetään liikkumisympäristöjen laatuun ja vihreyteen liittyviä mieltymyksiä sekä niihin kytkeytyviä hyvinvointivaikutuksia ja näiden alueellista, vuodenaikaista ja yhdenvertaista saatavuutta. Jatkoimme keskustelua aiheesta seminaarin jälkeen pidetyssä GREENTRAVEL-työpajassa, jossa keskityimme vehreyden rooliin kaupunkien liikkumisympäristöissä sekä tapoihin tuoda vehreys näkyvämmin osaksi liikkumisympäristöjen suunnittelua.

Tuuli Toivonen raottaa matka-aikamatriisin historiaa
Christoph Fink esittelee uuden matka-aika-aineiston yksityiskohtia
Elias Willberg kertoo miten saavutettavuus on muuttunut pääkaupunkiseudulla kuluneiden kymmenen vuoden aikana
Esiintyjät vastaamassa yleisön kysymyksiin


Klikkaa kuvaa avataksesi esityksen.

The case for the societal benefit of user-generated big data research – DGL responds to EU on research data access

Authors: Tatu Leppämäki, Tuuli Toivonen, Olle Järv together with other Digital Geography Lab members

The Digital Services Act (DSA) is legislation by the European Union that aims at protecting the users of and mitigating risks caused by online platforms, covering anything from social media sites to search engines and online retailers. It does this by obligating the platforms to, for example, be transparent about content recommendation systems, and effectively tackling content manipulation and spreading of disinformation. Due to their significant effect on our societies, the legislation sets more obligations for very large online platforms (VLOP): this class of platforms include social media giants, such as Facebook, Youtube, Instagram, Twitter, and Tiktok.

As a research group that has successfully applied user-generated data to study multitude of topics, our interest in the legislation stems from its sections that obligate VLOPs to give means to access data uploaded on their platform for appropriate research purposes (Article 40 of the act). While these purposes are limited for scrutinizing the systemic risks caused by the platforms in the legislation, we believe there is much potential for social good through responsible research employing public user-generated data.

The European Commission recently asked for feedback on the implementation of researcher data access under the DSA. Drawing from a decade of big data research, our response argues for the benefits of researcher data access beyond studying systemic risks. The response is split into a short opinion text and direct responses to some of the questions posed by the Commission (find the guiding questions here). You can read our response below or via the feedback service. If you’re a researcher using or curious about data from online platforms, or just an interested citizen in Europe or elsewhere, you may give feedback until the midnight of Wednesday, 31st of May 2023. Continue reading “The case for the societal benefit of user-generated big data research – DGL responds to EU on research data access”

Elias Willberg defending June 2nd

Yay! Elias Willberg will defend his PhD thesis “Measuring sustainable accessibility: Geospatial approaches toward integrating people and the environment”

Opponent professor Trisalyn Nelson, Jack and Laura Dangermond Endowed Chair of Geography, University of California, Santa Barbara, custos Tuuli Toivonen

Time: Friday 2nd June, 12 o’clock noon
Place: Suomen Laki- sali, Porthania, Yliopistonkatu 3

Abstract of the thesis

The central challenge of our societies is how to satisfy people’s basic needs and guarantee a good life for everyone, while staying within the safe planetary limits. Spatial accessibility, meaning the potential of opportunities to interact with other people, activities, and places, is essential for social and environmental sustainability. During recent decades, measures of accessibility have become an everyday tool for urban and transport researchers. By examining the satisfaction of basic needs, accessibility strongly links to social well-being and equity. Accessibility-oriented planning can at best enable environmentally sustainable solutions, which do not increase travel demand but support shorter distances and thus the increase of walking and cycling. In reality, improving accessibility is often based on improving the conditions of motorised transport, and the results can be environmentally harmful. Such contradictions remain sparsely studied in accessibility research due to the lack of holistic approaches. Most often, social and environmental concerns are addressed separately, even if the integration of perspectives would be central to promoting sustainability.

In my thesis, I take up this integration challenge. I develop conceptual and methodological approaches to bridge social equity and environmental sustainability in accessibility research. Conceptually, I present a model for measuring accessibility that integrates social equity, environmental boundaries, and their tensions and trade-offs. Methodologically, I leverage the opportunities of new geospatial data and tools. I develop geographical measures of accessibility, which are sensitive to the variation between people and temporal conditions, as well as to the travel environment. Empirically, I approach the integration of social and environmental goals from the perspective of contemporary themes in sustainable accessibility. The themes include the idea of 15-minute cities, environmental exposures during travel, and bike-sharing systems as accessibility promoters. I use the Helsinki Metropolitan Area to test the new approaches empirically. Hence, my thesis also offers place-specific understanding on accessibility and mobility patterns in this area. I focus my thesis on walking and cycling due to their vital role for sustainable transport. The thesis consists of five scientific articles, the first of which is conceptual, the second an overview of data sources, and the last three empirical and methodological, located in Helsinki or in the wider metropolitan area.

The results of my thesis show the need, but also present means, to combine social equity and environmental sustainability when measuring accessibility. There is a need to diversify the ways in which the travel costs are measured. Accessibility should increasingly be measured not only through travel time, but considering its full costs, such as environmental impacts. Furthermore, measures based on travel time should be developed to be more sensitive to the temporal and interpersonal variation. My results show that this can yield more realistic presentations of accessibility, especially concerning the opportunities of less mobile groups to travel sustainably. Promisingly, new geospatial data and tools offer increasingly means for the necessary development work, supporting researchers and planners. However, there is a need for careful consideration in the selection of data sources, as limitations and biases abound. Finally, my thesis highlights that multidisciplinary and transdisciplinary approaches are essential in accessibility research to support evidence-based decision-making that promotes real progress towards sustainability.

The thesis synopsis is available in HELDA:

The thesis contains the following scientific articles:

  1. Willberg, E., Tenkanen, H., Miller, H. J., Pereira, R. H. M., & Toivonen, T. (2023). Measuring just accessibility within planetary boundaries. Published as a preprint:
  2. Willberg, E., Tenkanen, H., Poom, A., Salonen, M., & Toivonen, T. (2021). Comparing spatial data sources for cycling studies – a review. In M. Mladenović, T. Toivonen, E. Willberg, & K. T. Geurs (Eds.), Transport in Human Scale Cities (pp. 169–187). Edward Elgar Publishing Limited.
  3. Willberg, E., Salonen, M., & Toivonen, T. (2021). What do trip data reveal about bike-sharing system users? Journal of Transport Geography, 91, 102971.
  4. Willberg, E., Fink, C., Toivonen, T. (2023). The 15-minute city for all? – Measuring individual and temporal variations in walking accessibility. Journal of Transport Geography 106, 103521.
  5. Willberg, E., Poom, A., Helle, J., & Toivonen, T. (2023). Cyclists’ exposure to air pollution, noise, and greenery: A population-level spatial analysis approach. International Journal of Health Geographics 22, 5.

New paper out: How to best map greenery from a human perspective? Comparing computational measurements with human perception

Fresh from the press, Jussi Torkko’s MSc thesis has been turned to an article, and it’s out in Frontiers in Sustainable Cities!

Torkko, J., Poom, A. Willberg, E. & Toivonen T. (2023) How to best map greenery from a human perspective? Comparing computational measurements with human perception, Frontiers in Sustainable Cities, 5,

Urban greenery has been shown to impact the quality of life in our urbanizing societies. While greenery is traditionally mapped top-down, alternative computational approaches have emerged for mapping greenery from the street level to mimic human sight. Despite the variety of these novel mapping approaches, it has remained unclear how well they reflect human perception in reality. We compared a range of both novel and traditional mapping methods with the self-reported perception of urban greenery at randomly selected study sites across Helsinki, the capital of Finland.

The mapping methods included both image segmentation and point cloud-based methods to capture human perspective as well as traditional approaches taking the top-down perspective, i.e., land cover and remote sensing-based mapping methods. The results suggest that all the methods tested are strongly associated with the human perception of greenery at the street-level. However, mapped greenery values were consistently lower than the perceived values.

Our results support the use of semantic image segmentation methods over color segmentation methods for greenery extraction to be closer to human perception. Point cloud-based approaches and top-down methods can be used as alternatives to image segmentation in case data coverage for the latter is limited. The results highlight a further research need for a comprehensive evaluation on how human perspective should be mimicked in different temporal and spatial conditions.

See a longer post about Jussi’s work in the lab blog 3/2022!

Figure 4. Mapped greenery values for the study sites. Vertical bar hue is weighted on the value with higher values having darker green hues and vice versa. Perceived greenery is highlighted in red for comparison.

The work relates to the finished Horizon 2020 funded HOPE-project (2019-21) and ongoing ERC funded GREENTRAVEL project  at the Digital Geography Lab as well the Exposure to greenery and noise in active travel environments: opportunities for making cities pleasant, healthy and sustainable at the Mobility Lab of the University of Tartu.

The Digital Geography Lab is an interdisciplinary research team focusing on spatial Big Data analytics for fair and sustainable societies.

How is our research related to Sustainable Development Goals (SDGs)?

Authors: Janika Raun with all Digital Geography Lab members

In 2015, all United Nations member states adopted the 2030 Agenda for Sustainable Development that includes 17 Sustainable Development Goals (SDGs), each with their own set of associated targets (169 in total). The goals address social, economic, and environmental development aspects and call for urgent action, e.g., to end poverty, reduce inequalities and tackle climate change (Fig. 1). The SDGs are increasingly used by different actors of the society to structure and communicate their actions around sustainability.Figure 1. 17 Sustainable Development Goals. Source:

Why the SDGs matter for us in DGL?

Universities play a crucial role in the achievement of SDGs as knowledge, innovation, evidence-based solutions, and good quality education are the basis for reaching the targets. As an interdisciplinary research group focusing on spatial Big Data analytics for fair and sustainable societies, we have always worked towards advancing sustainability. As SDGs, despite critique towards them (Arora-Jonsson, 2023), are increasingly used to communicate the sustainability actions in the society, we decided to map also our research activities at the Digital Geography Lab against the SDGs.

Continue reading “How is our research related to Sustainable Development Goals (SDGs)?”

Releasing the new Travel Time Matrix and GREENTRAVEL project 17th May 2023!

Howwell-connected is the Helsinki region for drivers, cyclists or public transport users? Does greenery support health and wellbeing during travel? How to plan for equal travel access and environmental sustainability? How are equal travel access and environmental sustainability related?

If you want to hear and discuss more about these topics, join us on 17 Mayin Think Corner (9.30-11.00) and Porthania Urbarium (11.30-13.00). The event is organized by the University of Helsinki’s Digital Geography Lab.

The event consists of two sessions. In the first morning session  ( 9.30-11.00), we will launch the new Travel Time Matrix 2023 for Helsinki region. The matrix is an interactive open access dataset that allows investigation of travel times for different travel modes in the Helsinki region. This widely used dataset has been published since 2013. It is now published for the fourth time, allowing for examining  changes in accessibility structures over an even longer period of time. During this session, there will be a presentation of the purpose and development of the matrix by the researchers. The stakeholders from the cities will also tell about their uses and experiences with the Matrix.

After launching the matrix, we will present our next big project GREENTRAVEL (2023 –2028). The goal of the project is to better understand the importance of urban greenery during people’s travel, its impacts on human well-being and health, and the equality of green travel environments. The event will be both in Finnish and English.

The second session of the event (11.30-13.00) is the GREENTRAVEL project workshop. The workshop aims to encourage cross-sectional discussion on how greenery is understood from a travel perspective, what wellbeing benefits it is expected to produce and how it can be better incorporated in current green infrastructure and travel and mobility planning.

Coffee will be served after the first part of the event. We also offer coffee and snacks for those who participate in the workshop.

Please register to participate by 12 May by filling the registration form.



Pääkaupunkiseudun uusi matka-aikamatriisi julki 17.5.2023!

Miten saavutettava pääkaupunkiseutu on autoilijalle, pyöräilijälle tai joukkoliikenteen matkustajalle? Tukeeko kaupunkiympäristön vihreys miellyttävää ja terveellistä liikkumista? Miten on liikkumismahdollisuuksien tasa-arvon ja ympäristöllisen kestävyyden laita? 

 Tervetuloa kuulemaan ja keskustelemaan näistä teemoista Helsingin yliopiston 17.5 Tiedekulmaan (9.30-11.00) ja Porthanian Urbariumiin (11.30-13.00). Digital Geography Lab-tutkimusryhmän järjestämään tilaisuuteen.

Tilaisuuden ensimmäisessä osassa (klo 9.30-11.00) julkaistaan pääkaupunkiseudun uusi matka-aikamatriisi 2023. Matka-aikamatriisi on avoin paikkatietoaineisto, joka mahdollistaa matka-aikojen vertailun eri kulkutavoilla pääkaupunkiseudulla. Paljon käytetty tietoaineisto on ollut saatavilla vuodesta 2013 lähtien. Se julkaistaan nyt neljättä kertaa, mikä sallii saavutettavuudessa tapahtuneiden muutosten tarkastelun entistä pidemmältä ajalta. Tilaisuudessa esitellään Matka-aikamatriisin tuottamisen taustaa, käyttömahdollisuuksia sekä kuullaan kommentteja käyttäjiltä.

Matka-aikamatriisin julkaisun jälkeen suuntaamme katseen tulevaan. Esittelemme Digital Geography Labissa juuri käynnistetyn viisivuotisen GREENTRAVEL-tutkimushankkeen, jossa selvitetään matkustusympäristöjen laatuun ja vihreyteen liittyviä mieltymyksiä sekä niihin kytkeytyviä hyvinvointivaikutuksia ja näiden alueellista, vuodenaikaista ja yhdenvertaista saatavuutta.

Tilaisuuden toinen osa (klo 11.30-13.00) koostuu GREENTRAVEL-hanketyöpajasta. Työpajan tavoitteena on kerätä näkemyksiä kaupunki- ja liikennesuunnittelun tietotarpeista liikkumisympäristöjen laadun osalta, pohtia liikkumisympäristön laadun hyvinvointivaikutuksia, oppia kaupunkien käynnissä olevista strategia- tai suunnitteluprosesseista sekä pyrkiä edistämään kaupunkien ja tutkijoiden yhteistyötä hankkeen aikana.

Tilaisuuden ensimmäisen osan jälkeen on kahvitarjoilu. Työpajaan osallistuville tarjoamme myös pientä purtavaa.

Rekisteröidy mukaan 12.5. mennessä täyttämällä ilmoittautumislomake.



Join our special session at ECTQG’23 in September

Olle Järv (University of Helsinki) and Ate Poorthuis (KU Leuven) organize a special session focusing on how dynamic mobility flows form functioning systems like communities, urban networks and regions at the European Colloquium on Theoretical and Quantitative Geography 2023. The ECTQG’23 takes place 14.–17. September 2023 in Braga, Portugal.

Join us and submit your abstract HERE. Abstract deadline: 15th May 2023. We plan to organize a special issue in a peer-reviewed geographical journal in 2023 and look forward to your contribution on the scope, in addition to our ongoing research in BORDERSPACE project. See our session description, below:

Special Session “From dynamic mobility flows to functional systems: Communities, urban networks, and regions”

The analysis of functional systems through spatial interactions has been a long-standing interest in quantitative geography. While traditional approaches often focused on single cities or countries, limited themselves to specific kinds of mobility (e.g. commuting or migration), or a single point-in-time, new (big) data sources and computational methods have opened up new avenues. By not only providing new insights on temporal rhythms of functional systems, these systems can also be investigated at larger global and cross-country scales, and capture for more heterogeneous types of mobility (e.g. cross-border commuting, multilocal living, recreation and social networks). This can shed new light on, for example, border regions from different countries forming one functional system regarding peoples’ daily practices or the temporal rhythms of urban networks.

Continue reading “Join our special session at ECTQG’23 in September”

New study on cyclists’ environmental exposure in Helsinki

Title: Cyclists’ exposure to air pollution, noise, and greenery: a population-level spatial analysis approach

Published in International Journal of Health Geographics

Authors: Elias Willberg, Age Poom, Joose Helle, Tuuli Toivonen

photo by Christoph Fink

New study assesses the healthiness and pleasantness of cycling in Helsinki.

[press release]

Exposure to environmental pollutants, such as particulate matter and noise, can significantly contribute to the prevalence of respiratory and cardiovascular diseases. At the same time, pleasant and green environments have shown to reduce the harm of negative exposures and support health through various pathways. Reducing negative exposures and increasing positive ones is recognized as effective ways to promote public health and people’s well-being.

Continue reading “New study on cyclists’ environmental exposure in Helsinki”