New paper on optimal bike network planning

Our paper Bike Network Planning in Limited Urban Space was accepted for publication in Transportation Research Part B: Methodological!

This paper was part of the e-bike city project, a multidisciplinary initiative at the department exploring the effects of a radically changed urban road space with priority on cycling. Planning a suitable bike network is a core challenge in this project. In our paper, we introduce a novel optimization method for placing new bike lanes with minimal impact on other travel modes.

Our approach leverages the concept of Pareto-optimality: When car lanes are repurposed as bike lanes, car travel times inevitably increase. The key question is: By how much? Pareto-optimal solutions are the street networks that present the best trade-off between car accessibility and bikeability. To quantify bikeability, we introduce the concept of “perceived bike travel time”, based on research showing that cyclists perceive dedicated bike lanes as faster. Our experiments show that the optimization approach outperforms other methods by proposing networks that have both lower car travel times and lower perceived bike travel times.

Check out our paper or get in touch if you are interested to know more!

Further resources:

A New Tool for Transforming Urban Transportation Systems Without Building New Roads

A new paper titled “Designing an E-Bike City: An automated process for network-wide multimodal road space reallocation” was published in the Journal of Cycling and Micromobility Research.

How can we add transport capacity for rapidly growing urban populations? How can urban transportation systems be transformed for lower emissions within the short time available? In dense cities, adding transport infrastructure is expensive, takes many years of construction, and faces restrictions by historical buildings. Our research proposes a faster and cheaper approach: We have developed an automated tool that redesigns urban transportation systems only by reorganizing lanes on existing roads.

The SNMan – Street Network Manipulator is a new open-source software that allows researchers and planners to generate alternative transportation networks within existing road space. It can handle any scale, from individual blocks to entire cities. Depending on the goals set, it can add bike lanes, bus lanes, or green spaces, while reorganizing the rest so that buildings remain accessible by car and public transit remains functional. For example, Zurich’s roads could allocate 4x more space for cycling infrastructure while still satisfying these conditions.

Discover more in the recently published open-access paper!

Design steps applied to a single block.

New Paper on Understanding Complexity of Urban Traffic Prediction

A new paper titled “Enhancing Deep Learning-Based City-Wide Traffic Prediction Pipelines Through Complexity Analysis” was published in the journal Data Science for Transportation.

Our research introduces a novel metric that allows for the pre-modelling complexity evaluation of traffic prediction tasks. This metric, designed for computational efficiency and to be architecture-agnostic, assists in choosing the most suitable model for specific traffic scenarios. It advocates a shift from the traditional “bigger-is-better” approach in deep learning-based traffic prediction to a “just-enough” complexity model, optimizing both performance and resource utilization.

The findings enable a refined approach to modelling traffic prediction tasks, such as deciding between multiple chained predictions and a single-shot prediction. Furthermore, it allows for the segmentation of urban areas into regions of varying complexity, paving the way for deploying ensembles of models that better address diverse urban dynamics.

For more details on this transformative approach and its potential impacts on urban traffic management, check out our paper!

The same model, when trained on two datasets with differing intrinsic traffic complexities, achieves varying levels of effective model complexity during training.

Spatial Nudging framework presented at COSIT 2024 conference

A new paper, titled “Spatial Nudging: Converging Persuasive Technologies, Spatial Design, and Behavioral Theories”, was presented at the 16th International Conference on Spatial Information Theory (COSIT 2024).

This paper introduces the Spatial Nudging framework—a theory-driven approach that maps out nudging strategies in the mobility domain, with a focus on cycling. The framework integrates physical and digital interventions to promote sustainable mobility, drawing from behavioral theories such as Nudge Theory and the Theory of Affordances. Additionally, we propose a graph-based workflow that uses cognitive graphs and the Fine-to-Coarse heuristic to model how cyclists perceive their environment. This method generates cognitive routes that align perceived affordances with the physical environment, closely resembling real-world cycling trajectories.

For more details, check out our paper!

Ayda Grisiute presented at CRBAM 2024

Ayda Grisiute gave a talk at the 8th Cycling Research Board Meeting (CRBAM). The presentation, titled “Conceptualizing Spatial Nudging: A Theoretical Framework for Integrating Interventions to Promote Cycling“ introduced Spatial Nudging framework that delineates nudging practices in the mobility domain and offers a theoretically integrated perspective on promoting cycling through spatial interventions.

In addition, Ayda presented a poster titled “Building a Planning Tool for the E-Bike City Vision,” which showcased a web application created by two geomatics students. The tool helps urban planners reallocate road space for bike lanes using various optimization strategies.

Check out the poster here!

New paper in Computers, Environment and Urban Systems: introducing VeloNEMO ontology to harmonize bike network evaluations

As the ecosystem of transport planning and evaluation metrics, tools, methods, and services grows, there is a pressing need to enhance domain interoperability and interpretability. In our new paper, titled “An ontology-based approach for harmonizing metrics in bike network evaluations“ , we construct a formal ontology, VeloNEMO, a formal ontology designed to capture the key attributes of bike network evaluation metrics and resolve terminological inconsistencies across them. We also introduce a machine-readable knowledge graph that compiles existing metrics, allowing for more efficient meta-analyses of various evaluation strategies. To further enhance transparency, we offer recommendations for making metric descriptions more comparable across different evaluation approaches.

For more details, check out our paper!

New paper in Applied Energy: V2G4Carsharing – A simulation study for 2030

What is the potential for integrating vehicle-to-grid with car sharing in the future? As part of the V2G4Carsharing project, we simulated scenarios for 2030 and quantified the benefits in terms of monetary savings and peak shaving effect. In our case study done in collaboration with the swiss car sharing provider Mobility, we found that Mobility could offer flexibilities between 12 to 50 MW, dependent on the scenario. There is a sweet spot where both car sharing and power grid operators benefit.

Our paper titled Vehicle-to-grid for car sharing – A simulation study for 2030 was now published in Applied Energy! Check out the paper here.

Get in touch if you are interested to learn more, or checkout our project code base and the car sharing simulator.

New Paper in Transportation Research Part C: Quantifying the Dynamic Predictability of Train Delays

Our paper on “Quantifying the dynamic predictability of train delay with uncertainty-aware neural networks” has been published in Transportation Research Part C!

In light of the importance of accurate delay prediction for transport services and passengers, many predictive methods have been proposed. However, they hardly account for the involved uncertainty and there is a lack of work analysing the dynamic predictability over time. We fill this gap with an uncertainty-aware neural network and a framework for describing the predictability by the prediction horizon. The results on Swiss train delay data show 1) an exponential decay of the predictability by the horizon, 2) a significant portion of (aleatoric) data uncertainty in contrast to model uncertainty, and clear advantages of the NN compared to MC models.

For more details, check out our paper! This work was done in collaboration with the Institute for Trans­port Plan­ning and Sys­tems at ETH Zurich.

New paper published in the Journal of Transport Geography – Car sharing demand prediction

Our paper titled “Spatially-aware station based car-sharing demand prediction” is now published open-access in the Journal of Transport Geography!

In this paper, we analyze long-term station-based car-sharing demand (i.e., the monthly number of reservations per station), and fit local and global models to the demand. Spatially-aware models and methods for interpretability improved our understanding of the effect of different features in varying locations. Our models can assist in planning new car sharing stations, an important avenue towards more sustainable transportation.

This work is part of the Vehicle-to-grid for Car Sharing project.

New paper in Transportation Research Part D – Time flexibility of car sharing users

Our paper titled “Vehicle-to-grid and car sharing: Willingness for flexibility in reservation times in Switzerland” presents the results of a stated preference survey conducted with 777 Mobility car sharing users in Switzerland. This study was part of our Vehicle-to-grid for Car Sharing project, funded by the Swiss Federal Office of Energy, where we aim to analyze the potential of integrating V2G in car sharing services. Understanding the time flexibility of car sharing users is crucial for designing dynamic pricing strategies, for example with the goal to incentivize users to shift their reservation times and thereby to increase the flexibility for V2G.
We found the value of time to be 31CHF/h on average, where older adults, lower income groups and employed adults tend to have lower flexibility. For more details, see our paper published in Transportation Research Part D.