BikeNetKit launched for designing bicycle networks

We just launched bikenetkit.org – the platform visualizing our free, open-source Python tools for designing well-connected bicycle infrastructure. The platform covers 412 cities in Europe – Check it out!

After 8 years of researching the topic together with 17 amazing collaborators, and a year of focused programming by Manuel, Michael, and several other NERDS / ex-NERDS including Anastassia, Carlson, Clément, Mariana, and web/viz development by renown Data Design expert Moritz Stefaner / Truth & Beauty as part of the Innovation Explorer grant we won last year and the EU project JUST STREETS, our platform BikeNetKit is now online and ready for use.

See ITU’s promo video:

And our short explainer:

BikeNetKit is a collection of free, open-source Python software tools to help plan and develop bicycle networks, developed collaboratively at github.com/BikeNetKit. It turns our past 8 years of research efforts into polished software tools. Urban planners and citizens can run them on their own city with their own data, exploring many scenarios to make safe cycling happen.

The kit comes for now with 5 tools packaged as Python libraries: GrowBikeNet, LinkBikeNet, FixBikeNet, SortBikeNet, and superblockify. Further, it comes with BikeNetLib which offers general utilities for researching or working with bicycle networks.

For BikeNetLib we have also set up our own overpass server with the added side-effect of facilitating university education for geospatial data science at ITU and elsewhere.

We are happy if BikeNetKit grows into a wider community effort from the bicycle network/mobility/urbanist community. If you would like to contribute, have a look at: https://github.com/BikeNetKit

Even just trying it out and giving us feedback is very helpful. If you like this project, you can help us by following BikeNetKit on LinkedIn, Mastodon, Bluesky, or Youtube, and feel free to tell your urban planners and politicians about it.

Thanks for spreading the word, and enjoy the ride! 🚲

NERDS / BikeNetKit at the Digital Tech Summit

Yesterday, Michael presented at the Digital Tech Summit our ongoing innovative efforts for BikeNetKit, the bicycle network planning and visualization platform which launches on Monday at bikenetkit.org

The Digital Tech Summit is Denmark’s largest AI and digital transformation expo with hundreds of participants. Michael’s talk and live demo was titled “BikeNetKit: Open Bicycle Network Algorithms for boosting the Green Transition of European Cities”. Below some impressions:

Download the slides here: https://michael.szell.net/downloads/talk_szell2026bob.pdf

Next time BikeNetKit will be presented at Kortdage in Aalborg, on Nov 19th.
Stay tuned for BikeNetKit’s launch on monday!

Sofia Myrup Otero has joined NERDS

 

Sofia joins as a new industrial PhD student, coming with a Master’s degree in Quantitative Biology and Disease Modeling, and with several years of experience in modeling disease dynamics at Statens Serum Institute’s Department of Data Science and AI in Health.

Sofia is an industrial PhD student working jointly with PI Peter Bager at Statens Serum Institut and Jonas L Juul here in NERDS. Sofia is hired on Bager’s Project 2 grant from the Danish Fund for Independent Research. In her project, Sofia will use register data to study networks of infections with antimicrobial resistance in Denmark. We are excited to have you with us, Sofia. Welcome!

NERDS Research on the Economic Complexity of the Roman Empire

The economic complexity of the Roman Empire as inferred from Latin inscriptions by Matteo Mazzamurro, Petra Heřmánková, Michele Coscia, and Tom Brughmans, published in npj Complexity.

Economic complexity is a powerful tool to estimate the productive capabilities and future growth of modern economies. Little is known about how economic complexity evolves over long periods in history. In this paper, we use archeological evidence from the Roman Empire in the form of short texts preserved on a durable material (i.e., inscriptions) to estimate the economic complexity of the various provinces of the empire. By connecting the occupations listed in the text of inscriptions with the location in which the inscribed objects were found, we can estimate that the most complex areas during the first four centuries of the Roman Empire have a remarkable and statistically significant overlap with the most complex countries today. This is a surprising result running counter the expectations from historiography, and we lack an explanation for the reason of this supposed preservation of economic complexity through the ages – both factors pointing at the need of future work to integrate Greek inscriptions. However, this evidence provides a suggestion about how difficult the development of economic capabilities might be.

New NERDS paper on investigating the robustness of a Danish voting advice algorithm

Last month Giovanni Astante (who worked on the topic during his research stay at NERDS) presented our work (w. Roberta Sinatra) on “Investigating the Robustness of a Danish Voting Advice Algorithm” (VAA) at the European Conference on Algorithmic Fairness.

Now the paper is finally out in the Proceedings of Machine Learning Research!
You can find a copy here –> https://proceedings.mlr.press/v350/astante26a.html

We look at a popular VAA (called ‘Kandidattesten’), developed by the large media house Politiken, and investigated the robustness of its matching algorithm.

In past Danish elections 62% of eligible voters used some form of voting assistance algorithms (‘Valgtest’ in danish) one month prior to the election and 45% reported they followed the recommendation of a VAA when voting. This means these voting tools can have a large influence on election results.

Through a freedom of information request we got access to the algorithm used to match users and political candidates. The system functions by users filling out a questionnaire which is compared to a database of answers from candidates. Users are then presented candidates with highest agreement.

These systems have been studied in the past (mostly how humans interact with them), but so far nobody has tested their robustness. We study how minor modifications to the algorithm’s weights can change the outcome of which political candidates are recommended. In addition, we study how dropping questions, i.e. calculating match similarity based on fewer questions (than the original 20), affects which candidates are recommended.

Our results demonstrate that even minor tweaks to the algorithm can produce entirely different outcomes, potentially affecting outcomes of political elections. A marginally changed matching algorithm can recommend entirely different political candidates, from different political parties.

Based on our findings we provide recommendations to VAA developers and policy makers, on how to monitor and evaluate the robustness of these systems.

Giovanni Astante presenting our work at ECAF 2026, in a fantastic auditorium

New NERDS paper on the effectiveness of epidemic mitigation strategies

New NERDS paper out! Congratulations to our PhD student Morten Rahbæk Boilesen on publishing his first article!

Are fast test results preferable to high test sensitivity in contact-tracing strategies? This question is addressed by Morten Rahbæk Boilesen, Kaare Græsbøll and Jonas L. Juul in their modelling study of the dynamics of contact tracing, testing and isolation strategies in epidemic outbreaks. Here is a description of their paper:

During disease outbreaks, public health officials might face a decision on whether to use rapid tests that give quick but sometimes inaccurate results, or slower and more precise tests. This choice matters because delays in diagnosis slow down contact tracing, allowing infected and their potential secondary infections to spread illness longer.

Here, we use mathematical modeling to examine the trade-off between test speed and test accuracy. We use the mathematical model to simulate epidemic outbreaks with different levels of contact tracing efficiency, test turnaround time and test sensitivity. In each case, we evaluate whether disease mitigation is best with slow-and-accurate tests or fast-and-inaccurate tests.

For diseases similar to COVID-19, we find that accurate tests with test turnaround time less than four days generally reduce transmission better than rapid, less reliable tests. However, when contact tracing is highly efficient, faster results become advantageous.We show that if test sensitivity is proportional to the viral loads of the infected, rapid tests become more favourable overall as opposed to modelling the test sensitivity as a constant value independent of the viral loads of the infected.

Finally, our analysis shows that when contact tracing isn’t feasible, neither rapid nor accurate testing outperforms simply having people self-isolate without testing infrastructure.

This work can help guide testing strategy decisions when an epidemic is raging, revealing that prioritizing speed can become a viable strategy to reduce transmission when testing infrastructure is under stress.

A figure showing effective reproduction number under mitigation strategies.

Anthony Zhou has joined NERDS


Anthony Zhou has joined NERDS as a Research Assistant in the FemVision Project. Anthony recently graduated from the Social Data Science Msc Program of Copenhagen University and has a Bachelor in Public Health and Data Science from the University of Washington.  Anthony has experience both with complex data pipelines as well as in studying  Illicit maritime networks.

We’re happy to have you on board, Anthony!

Anders Giovanni Møller defends his PhD: “AI in Modern Society: From computational methods to societal consequences”

Big congratulations to Anders for successfully defending his PhD thesis on how AI is changing Computational Social Science and the Web. The Committee was composed by Elisa Mekler, Robert West, and Johannes Bjerva. His very proud supervisor is Luca Aiello.

During his three years with NERDS, Anders has published 6 papers in the areas NLP and CSS, pioneering topics such as synthetic data generation with LLMs and AI persuasion. His graduation officially concludes the COCOONS project.

Anders has now started a job in the industry as AI Lead of Polaris, in Copenhagen.

In bocca al lupo, Anders!