A Dent in Someone Else's Line

An Essay on movement, data and whose map gets drawn

introduction

The Quantified Scientist runs in circles. Ten kilometers through public space – around a famous monument in Vienna. His goal is not to train, but to generate data. He tests fitness devices and health trackers. Specifically, their GPS accuracy. By running in circles again and again, the generated data is loaded into a digital map, making his movements visible as an imperfect, overlapping blue line. Each round is slightly different. The path never lands exactly on itself. The reason of which is absurd. A bend in the track, amplified by each round he runs. The quantified scientist had to give wide berth at this location, he explains, because tourists would appear repeatedly at that spot. The same exact space is ground to a range of different groups of people. They share no interaction, no common purpose. But through the perspective of one, the other groups don’t disappear. They show up as noise. As a dent in someone else’s perfect line. This essay takes this picture as a starting point. Connecting to de Certeau’s notion of the ordinary practitioner who navigates the ground, Bachelard’s tension of inhabited and geometrical spaces and the GPS collections of runner’s data of Strava Metro - it asks what happens when everyday movements are turned into raw, mathematical data that becomes material from which cities are being planned. It raises the question of whose map is drawn, and by whom?

drawing a line

The Quantified Scientist looks at the map. At the abstraction he has created by drawing a simple line through a complex space. A space shared by people. But the people don’t appear as such in the path he has constructed. They are seen solely as deviation, as a distur- bance in his data. De Certeau writes that “the activity of passers-by, is transformed into points that draw a totalizing and reversible line on the map. They allow us to grasp only a relic set in the nowhen of a surface of projection,” (De Certeau 1984, 97) and continues with “the trace left behind is substituted for the practice.” One could argue that The Quantified Scientist takes up the role of de Certeau’s voyeur-god: a position of observing through an abstract and theoretical model of efficiency in an urban context, rather than engaging with a concrete, living space. It’s this precise abstraction and simplification of a space that re- moves its essence. The blue line doesn’t capture the space, the aspects and realities of living entities. It measures the performance of a spatial realm by reducing it to a mathematical path. Coordi- nates sharing entry and exit points that construct an imaginary line. It captures movement through space, not the space itself. As Bachelard writes: “Inhabited space transcends geometrical space” (Gaston Bachelard, 1994, 47). And yet, it’s this exact reduced, geometrical trace that platforms like Strava collect, aggregate and provide as a form of knowledge on how a city is lived. The fitness tracker doesn’t just record movement. It shapes and produces it. Following Bruno Latour’s actor-network theory (Latour 1992, 256), the device is an actant that forms and translates the run into tangible data for the platform, and useful to the city. The runner thinks he is using a device for his own self-quantified goals. Simultaneously, the device is recruiting the user into producing this kind of specific, legible data. It’s the source of this action. An action that for most of us, usually remains unnoticed.

Repetition of movement has always formed space. That shortcut across the grass is inscribed by the people taking it, before any planner decides it should. These are called desire paths: informal trails formed by repeated movement, etching routes into space. What is new is that these etchings are no longer just physical – they become digital and collectable. Strava Metro makes this structure visible.

strava metro for urban planners

Urban planners rely on data to construct new or improve existing roads, paths or streets. Decisions about how a route flows, where it intersects and how it’s built, have immense impact on the efficien- cy, safety and structure of a city. This data has been, and still to a large extend is collected manually, oftentimes relying on free labor - volunteers that would sit at a corner of a street and count the cy- clists passing by. This would be done periodically, to stay up to date with how streets are used. A player new to this field is Strava, a platform used to track and record sport activities. Like the volunteers doing work for the city, Strava is also collecting free data from its users – being the cyclists, runners and other individuals. In 2014, Strava decided to sell this data as a service called Strava Metro. Additionally, to the manual labor that’s been done traditionally, Strava also collects anonymized demographic data, such as age or gender, which is linked to the in- dividual heat maps that are being collected and generated. In 2020, the decision was made to provide this data free of charge. Several municipalities in Ontario, Canada have been using it, and the ser- vice has over 100 million users worldwide – in combination with existing manual counting done by volunteers, as well as other data sets. Robinson et al. (2025, 10) describe how this creates a dependent relationship where the government is tied to data and expertise owned by corporations - an example of what Zuboff calls surveil- lance capitalism (Zuboff 2019, 806). The intentions of the user, which is recording their activities, don’t align with the intended data collection by the platform. This gap is what Zuboff refers to as behavioral surplus (Zuboff 2019, 797). The data itself reveals a deeper problem: Strava’s heatmap rep- resents a large quantity of people, but a quantity of mostly Middle-Aged Men in Lycra – a colloquial term that describes the fitness and affluence of this group of people, which is already well-served by existing infrastructure. The city, that is being planned from this data is one built around a very specific type of movement. And everyone around – the com- muter, the pedestrian, the tourist – remains as an indent in some- one else’s line. A factor to ignore, or even to correct, by the urban planner staring at their office screen.

conclusion

The indent in the line is not just a small deviation in an athletic endeavor. It's the consequence of what gets captured and what gets erased. What gets erased is the presence, the reality of the ordinary people. The runner's desire path, formed through repetition, is captured and compiled back into the systems that design the space in the first place. De Certeau's tactics - the walking, wandering or taking shortcuts - were once invisible to the map. Now they feed it. It's not just an accident. It's induced by the platform. While the runner has passed the tourists for the sixth time in a row, their relation didn't change. They proceed with the same intentions they had as before. Maybe in five years from now - there will be a separate path - just for the runners so the line can finally go into perfect form?

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references

Note / Use of AI: NotebookLM was used in research and help with bibliography / referencing. Claude was used for proofreading and correction of grammar and spelling.

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Bachelard, Gaston. 1994. The Poetics of Space. Translated by Maria Jolas. Boston: Beacon Press.

De Certeau, Michel. 1984. The Practice of Everyday Life. Translated by Steven Rendall. Berkeley: University of California Press.

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Latour, Bruno. 1992. "Where Are the Missing Masses? The Sociology of a Few Mundane Artifacts." In Shaping Technology/Building Society: Studies in Sociotechnical Change, edited by Wiebe E. Bijker and John Law, 225-258. Cambridge, MA: MIT Press.

Robinson, Pamela, Peter A. Johnson, Madison Vernooy, and Leorah Klein. 2025. "Strava Metro Data as an Urban Planning Input." International Journal of E-Planning Research 14 (1). https://doi.org/10.4018/IJEPR.368846.

"The Quantified Scientist." n.d. YouTube channel. Accessed June 7, 2026. https://www.youtube.com/@TheQuantifiedScientist.

Zuboff, Shoshana. 2019. The Age of Surveillance Capitalism: The Fight for a Human Future at the New Frontier of Power. New York: PublicAffairs.