This article features insights from Lea S. Zuckriegl, Research Associate at the Technical University of Munich (TUM), who leads the development of the Comfort-Based Accessibility Tool (CAT) within the InclusiveSpaces project.
Introduction to the technology
Could you describe the “Comfort-based Accessibility Tool” and how it fits into the InclusiveSpaces project?
Accessibility planning means planning a city focusing on how easy it is for people to get to the places they need, such as school, work, shops, or parks. It looks at how people move, like walking, wheelchair, or cycling, where things are located, when people can travel, and what personal needs they might have. Traditional maps and planning tools often show how far someone could go, but not whether the journey would be comfortable or possible for everyone. This kind of planning is important because not everyone finds it equally easy to move around the city. Some people might face problems like steep streets, loud traffic, uneven sidewalks, or missing crossings.
The Comfort-Based Accessibility Tool (CAT) helps to fix this. It shows how comfort or discomfort, like noise, bad pavement, or steep hills, can make places feel far, even if they are close. This helps city planners see which areas need improvement so that more people can move around safely and comfortably. CAT serves both professional and public audiences. City planners, policymakers, and organizations can use it to better understand and address urban accessibility challenges. At the same time, citizens can adjust comfort settings to see how accessibility changes depending on their own preferences or needs. This dual approach makes CAT a key element of the InclusiveSpaces project, supporting the creation of more inclusive and user-centered urban environments and helping to plan that everyone can reach the places they need in their daily life, easily, safely, and without stress.
Why focus on comfort (terrain, noise, temperature, obstacles,) in addition to traditional accessibility calculations?
Most accessibility tools focus on travel time, distance, cost, or emissions. These tools do not take into account how a journey feels to the person making it. People may avoid or be unable to complete a trip because of certain environmental conditions. When comfort is included in the analysis, the tool presents a clearer picture of everyday mobility. This allows professionals to better understand which barriers prevent some individuals from participating in daily activities.
Features
What are the main features of the tool, for example, how does it provide realistic insights and route choices for users?
CAT works through an interactive map. A user selects a starting point, walking speed, and a time limit that reflects their walking ability. The user then chooses comfort factors that may influence the travel experience. The tool produces two catchment areas. One is based on walking speed and time alone. The other reflects the selected comfort preferences. Comparing the two areas allows users and professionals to see how accessibility changes when comfort is considered.
How do users customise the preferences according to their personal comfort needs?
Users can select discomfort factors from a menu and choose a level on the discomfort scale (ranging from “Barely Noticeable” to “Totally Unbearable”). These weights are integrated into the algorithm to generate an individualized comfort-based catchment area.
For users wishing to understand accessibility for groups vulnerable to exclusion (such as wheelchair users, parents with strollers, or visually impaired people), CAT provides predefined profiles. With one click, these profiles automatically set typical discomfort features and walking speeds. They are based on qualitative interview insights and illustrate how accessibility can differ for various groups.
Data and conditions
What types of environmental or mobility-condition data does the tool capture or integrate (terrain, weather, noise…)?
CAT is implemented in two demonstration sites: Hamburg (Germany) and Penteli (Greece). It primarily relies on municipal datasets and supplements them with open-access data from OpenStreetMap.org when needed.
Hamburg offers a rich, high-quality digital dataset due to its extensive data infrastructure in an open-access geoportal. Penteli, as a small municipality, faces constraints in staff capacity, funding, and time for maintaining digital data. This contrast reflects a broader challenge: the growing digital divide between large, well-resourced cities and smaller communities. Addressing this gap through support and cooperation is essential so that all municipalities can benefit from digital tools fostering sustainable development.
Urban integration
How does the tool identify and visualise comfort-based accessibility areas within the city?
CAT generates catchment areas based on the user’s starting point, walking speed, and selected comfort preferences. In addition, comfort-related data layers visualize where specific comfort aspects are lacking across the city. These maps reveal patterns of discomfort and highlight neighborhoods that may require targeted improvements.
For the Municipality of Penteli, this enables quick identification of areas needing upgrades and supports comfort-sensitive planning for future developments.
Testing
What testing or piloting has been done (or is planned) to validate the usability of the comfort-based accessibility and real-time responsiveness?
CAT was tested with built-environment experts (Ntotal = 6) and citizens or representatives from social organizations (Ntotal = 5). Testers explored the tool independently and submitted structured feedback. The evaluation revealed improvements needed in design, visual identity, navigation, and data communication.
Since the September 2025 testing phase, the feedback has been implemented in the updated version of CAT. Developers are also working with a social organization in Munich to strengthen the tool’s digital accessibility and ensure it better serves vulnerable-to-exclusion groups.
User-centricity
How are people with mobility challenges involved in shaping and using the tool (feedback loops, interviews, surveys…)?
The discomfort features included in CAT originate from a qualitative analysis of interviews with 81 people with mobility impairments, including people with disabilities, older adults, and caregivers. Not all identified discomforts can be included – for example, illegally parked cars on sidewalks are not captured in existing datasets and therefore cannot currently be mapped.
During the demonstration phase, CAT is being refined in collaboration with a social organization working with people with disabilities. In addition to a “How to use CAT” tutorial video, digital workshops will be organized for experts, community groups, and interested residents of Penteli. Through the municipality’s social services department, people with mobility challenges are invited to test the tool, creating continuous feedback loops for further improvements.
Future outlook
How do you envision the tool influencing urban design and mobility planning in the longer term?
CAT offers planners a new lens for identifying discomfort hotspots and understanding how different groups experience the urban environment. This supports more inclusive, evidence-based decisions on street design, infrastructure upgrades, and sustainable mobility strategies.
In the long term, the goal is to make CAT deployable in other cities through an open-source codebase. While implementation requires some programming expertise, collaboration and additional support – especially for smaller municipalities like Penteli – will help expand the tool’s adoption.
What has been the most rewarding insight or outcome from developing this tool so far?
One of the most rewarding outcomes has been the close collaboration with people in vulnerable situations. Through conversations, exchanges, and in-depth interviews, we gained insights that had often been overlooked in traditional mobility research and tool development. This cooperation highlights important gaps in how mobility has been understood and planned until now. It reinforces the need for mobility researchers and planners to design cities and municipalities that serve all people.