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The new value of curbs

Under the effect of the digital transition
Isabelle Baraud-Serfaty and Nathan Benamouzig


The objective of this article is to understand the changing value of the curb in the digital transition that we currently experience. Digital technologies impose a new perspective when it comes to understanding the curb. This reflection relies on observations of a variety of academic and non-academic pieces of literature. The analysis of the urban economy is therefore deeply linked to activities of the private sector in the studied space, here the curb. The change in behavior of private operators regarding the occupation of curb has been crucial to acknowledge that the curb is becoming a scarce and valuable resource. This transition is bringing up new challenges to various city operators, both public and private, especially since the curb is used in its physical form but also to obtain information through digital technologies. Digital technologies are also opening new models of governance of urban spaces, more specifically of the curb, which can serve public services and the residents. New possible models and tools of governance can also help cities deal with contemporary arising issues such as global warming, preservation of personal data, or public health emergencies.

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1In 2016, Alphabet Inc. launched an urban innovation company called Sidewalk Labs. Alphabet Inc., as one of the Big Five Tech companies, shows interest in urban planning. It chose to create a subsidiary dedicated to urban planning and named it after a particular object: the sidewalk. Sidewalk Labs aims at tackling “cities’ greatest challenges”i. In 2017, Sidewalk Labs instigated the project of transformation of Toronto, Sidewalk. This proposal was abandoned in 2020ii. However, this setback did not negate Alphabet’s interests in urban planning. Sidewalk Labs is the symbol that the sidewalk is being the outpost of the digital economy in cities. The sidewalk is originally a space along the road, which is dedicated to pedestrians. It has become an object of reflection in the transformation of cities. The primary use of the sidewalk seems to be the mobility of pedestrians. Often, the sidewalk is understood as the opposite of the road. This opposition reflects the conflict between (motorized) vehicles and pedestrians. On the contrary, the term curb, the edge separating the road from the sidewalk, is commonly inserted in a more nuanced manner. Curb management, for instance, is the management of pedestrians and non-pedestrian users and objects, either in mobility or still.

2Even though, curbs are centered upon the separation between two sides of a road, they are less focused on the role of pedestrians. We will therefore prefer the term curb to sidewalk. Moreover, modern uses of curbs reveal the importance of this space as a continuation of buildings (both residential and commercial). The curb is a space connecting private and public interests and nuisance.

3New actors, often private actors, are entering the curb as a playground, using its convenience and its lack of regulation to offer new types of services. Curbs are, by definition, limited in space and are used by countless companies in the digital world. This competition for the occupation of curbs is generating overcrowding of curbside spaces. Of course, curbs differ from city to city, and it is not the objective of this article to compare them except for the way they are modified through digitalization. Curb space is a key resource for a growing number of actors. Public authorities, therefore, have a role to play in the regulation or non-regulation of curbs, for it is central to the management of cities.

4The article examines the effects of the "digital transition" of curbs. The foundation of this transition is technological (e.g., geolocalization, smartphones, cloud computing, big data (Batty 2013)). However, it is important to realize that its effects are much broader, especially anthropological (Boullier 2016, Cardon, 2019). Digital innovations have transformed the ways people debate, work, learn, consume goods, meet, play, etc. This digital transition also changes economic models along three main axes (Baraud-Serfaty, 2017): (1) the emergence of “multitude” (individuals-residents-consumers are becoming producers)iii; (2) the generalization of customization; (3) the importance of “real-time” (synchronization may help optimizing flows). The development (or acceleration) of new technologies (such as augmented reality, virtual reality, or artificial intelligence) suggests that we are still at the beginning of this digital transition. There are undoubtedly other stages to come, the full effects of which are yet unseen.

5This article is mainly based on French and North American sources. The examples are mostly European-centered, so is the reflection on the role of curbs during and after the Covid-19 pandemic. However, the general observations and implications ought to be understood in a broader context. This article seeks at a better understanding of the curb, regardless of the location of its city or size of its street.

Literature review and methodology

6Whereas the changes in the value of the curb have rarely, if ever, been an object of academic research, this article tries to understand the digital transition of the curb through the prism of the multiple actors of public space. A curb is a singular object of study. It is at the crossing of the roadway and the sidewalk. It is valuable to both the public and private sectors, for it straddles several competencies of these actors. However, it must be noted that the curb should not be identified as an autonomous or independent object. The role of the curb depends on the will of operators to take advantage of its features, which might explain its absence in the field of political economics.

7The curb is a recent topic in academic literature. Curb studies originate in 2017-2018 from reflections on curb management in North America. Literature is therefore only beginning to analyze the curb as an academic topic. Moreover, understanding digital technologies might seem somehow technical and difficult to frame in the field of public policy. As for articles on smart cities, the first works often dealt with actors from the IT industry such as IBM or Cisco, which did not deal with curb management. The curb has been addressed when considering the economic and competitive features of mobility. In this domain, the curb remains a peripheral object of such analysis. As demonstrated throughout the article, the curb should not be reduced to its mobility component. It must be noted that because the digital transition is underway, the models are most likely to evolve in the following years and decades. The operators, who use the curb are evolving their strategies. In this domain, many initiatives have been launched by private actors, who seek to improve their models and adapt to technological development. While some of the operators mentioned in this article may disappear or change their model in the future, this does not invalidate the overall argument. This research is based on the use of strategic analysis tools.

8First, we tried to identify the actors for whom the curb is a valuable resource. To do so, three types of sources are to be looked at: academic publications, grey literature, and newspaper articles. As this subject is almost absent from academic publications, at least before 2020, this article is primarily based on grey literature and newspaper. These sources indicate weak signals, observations, or reflections, that have not been taken up by the academic literature. The curb is often analyzed from the perspective of curb management or mobility, whereas our objective is to focus on the curb as a rare and coveted resource. Moreover, the few academic sources on the value of the curb adopt the point of view of mobility or logistics specialists on the curb (Butueil 2018, Chaire Logistics City 2019, Chaire Logistics City 2020, Dablanc 2019). This article is about analyzing the curb itself as a space for plug-and-playiv. We could have relied more extensively on academic articles dealing with public space (Mongin 2012), even more specifically in the way public space is involved in the production of private actors – as most companies in the digital sector are private companies. However, these publications address the urban fabric through the lens of real estate (Le Goix 2008, Lorrain 2011) or urban services (Lorrain 2002). The issue at stake is not the role that the curb might have for mobility or logistics operators. It is also necessary to dispense with academic publications on the neoliberal city, as they do not take enough into account the role of digital actors (Baraud-Serfaty, 2022). This article operates a change of focal point. It emphasizes the importance of taking the curb for what it has become with the digital transition, a key resource.

9Before 2020, non-academic articles already analyzed the curb as an object of study in the digital transformation of cities. This change in the value of the curb has also soon been perceived in professional (Hao 2018), technology-focused media (Marshall 2017), and policy reports (ITF/OECD 2018, NACTO 2017). These articles and reports raised interrogations on the value of the curb and were the starting point of the reflection that led to the redaction of this article. The curb is no longer conceived as an abundant and accessible space, but rather as a scarce and therefore valuable assetv. These sources of grey literature make spell out the existence of dynamics other than the digital transition in the transformation of curbs, such as the environmental transition, the Covid-19 pandemic (Baraud-Serfaty 2020b), and the multiple emergent uses of the curb (Nanga 2020, Jeanmougin 2021, Baraud-Serfaty 2021a, b, c, Laurant 2019). Understanding the curb without linking it to its "mobility" feature is a change in perspective that forces us to look for sources in broader ways (such as in studies on urban logistics, new types of mobilities, e-commerce, etc.) and to understand the ongoing revolution not only as a digital transformation but also as a radical modification of our urban environment and lifestylesvi.

10These new reflections on the curb in the digital transitions are linked to the emergence in the academic field of literature devoted to the emergence of a new actor with a very specific economic model: the digital platforms (Rochet and Tirole 2003, Tirole 2018, Cardon 2019). Digital platforms are more and more understood as full-fledged actors in the urban landscape (Courmont and Le Galès 2019, Courmont 2021). In addition, the economic press (e.g., Les Échos in France) has relayed the work validating the hypothesis of a new value of the curb in the age of the digital transitionvii. Therefore, newspaper articles dealing with these matters are also central to addressing the new status of the curb.

Curb space scarcity under the effect of digitalization

11The overcrowding of curb spaces is far from being an emerging challenge. Already in 1882, Jules Brunfaut, a Belgian architect-engineer complained about the transformation of Paris, with the newly inaugurated gas-powered candelabras (candélabres à gaz), the store clutter (encombrement des boutiquiers), the “handcarts” (“voitures à bras”), and “vehicles containing children” (“véhicules renfermant des enfants”), strollers (Brunfaut 1882).

New clutter of curbs

12The ongoing digital transition has put forward the clutter of curbs as a renewed contemporary issue. The widespread use of smartphones and other connected portable devices has generalized the use of geolocation to offer services. New mobility equipment has appeared on curbs such as electric scooters (in France, it is now forbidden to drive them on the sidewalk, but they can still park along or on the curb), free-floating bicycles, vehicles for hire (e.g., Uber, Lyft, Bolt, or DiDi in China), who need to pick their passengers up and drop them off. In addition, e-commerce, and delivery companies such as Amazon, Deliveroo, and Glovo, are using curbs to deliver their products as part of their last-meter logistics. Such services require a pick-up/drop-off zone, which is the curb by convenience for both clients and delivery companies (Courmont 2018).

13When observing both mobility equipment and delivery companies, the acceleration of clutter of curb space is directly derived from the “three laws of the digital economy” (Cardon 2019): increasing returns to scale, the network effects, and the “winner(s) takes it all” law. The financialization of the digital economy has accentuated the monopolistic trend of the sector. It put forward the importance of marketing means used by each company to compete for the leading position in the sector. The goal of each actor is not to be cost-effective. Each actor only aims at crushing competitors and potential emerging competitors.

14The digital transition with the development of cloud computing and storage has had another consequence on the occupation of curbs. Companies have more interest in offering a range of services than in meeting an existing need. For instance, free-floating scooter companies will create the need for residents to ride a scooter instead of commuting or walking, but they will also provide the user information on combining scooter-riding with other means of transportation. Through this strategy, private operators aim at becoming essential to the residents. Digital advertisement and the constant occupation of curbs to gain visibility impose the product as an integrated object on the curb. Because electric scooters are present everywhere in a city, they are part of the everyday life of the inhabitants (pedestrians and drivers), who integrate the service into the public space almost as utilities. Service supply has preceded demand because digital companies need to obey the law of "winners take it all".

The curb, a key resource for city operators

15The sidewalk was first understood in relation to the roadway. Whereas the roadway was dedicated to cars, the sidewalk was considered a safe space for pedestrian mobility (Loukaitou-Sideris 2009). The sidewalk and the curb along were seen as spaces encompassing the mobility of urban actors. However, now, it shall be understood in a dimension of immobility organized into three key functions. Traditional operators of the local economy (shops and restaurants) are expanding their activity through the occupation of the curb. This expansion has proven useful, and therefore was accentuated during the Covid-19 pandemic. Indeed, as lockdowns and deconfinement came and went with the fluctuation in levels of contamination, the curb became the “waiting room of shops” (“salle d’attente des commerces”)viii due to the lengthening of queues in front of stores because of the implemented measures of physical distancing, the space for curbside pickup initiatives (“click-and-collect”), but also a space dedicated to the extension of terraces of cafés and restaurants. One last function of the curb shows up when looking at the activity of various operators of the city (Baraud-Serfaty 2021c). The curb is a resource, especially for digital platforms and free-floating services companies, which are producing new types of clutter. The curb should be understood as arising border between local and online commerce. As online shopping companies such as Amazon are treated as major threats to local businesses, one must acknowledge that curbs de facto are the unloading platforms (Townsend, 2020) and are the inevitable space between the delivery van and the domicile of the clientix. To perform their task fully, an online shopping company must access the curb.

16Among the multiplicity of occupations of the curb, micro-hubs embody the scarcity of the curb space. Micro-hubs are storage points for goods suitable for delivery by bicycle. These modules have been invented and installed on parking spots by a semi-public company, Sogaris, in collaboration with the City of Paris.x They aim at answering the difficulties encountered by the actors of urban logistics (Chaire Logistics city 2021). Micro-hubs consider the curb as a coveted resource for it encompasses beneficial features both in terms of mobility and fixed occupation. Sogaris apprehends the curb as a space subject to both the digital and environmental transitions. It facilitates delivery by bicycle at the expense of motorized vehicles. Bicycles are not dependent on large parking spaces as cars. The sector of logistics is adapting to changes caused by digital and environmental transitions. In doing so, logistics rely on occupying the curb while considering this space not only for curb-kissing purposes but to occupy it permanently. Reef is another example of the occupation of the curb. Reef suggests that available open public (and private) space can benefit the local community. The service proposed by Reef is the transformation of unoccupied urban space into “delivery-kitchens”, “micro-clinics”, or “on-site security” modules.xi Reef argues that their customized occupation of the curb space is benefitting the local community and economy The company provides modules at the request of the inhabitants according to their needs.xii Reef is exploiting an available yet profitable resource, free curb space.

17The digital transformation, as well as the environmental transition of cities, have brought new occupants of the public space and especially the curb. Indeed, municipalities and collectives of neighbors are putting forward the greening cities, both for their ecological value and for the improvement of the quality of life of the residents. The appearance of urban vegetable and herb gardens or urban meadows has produced another type of occupation of the curb. The curb is not properly reduced but is occupied durably in the interest of residents. This type of occupation is a collective and local taking over of the public space. The curb has a strategic position, as it is a space for inhabitants to create new living habits and practices. The public space is mediterraneanizing. The curb is more and more considered as the outdoor extension of homesxiii. The city of Paris, for instance, intends to give its inhabitants back the “10 square meters down the street” in suppressing parking lots.xiv This initiative can be understood as a way to compensate for the loss in the past years of 10 square meters on average of the size of housings in Ile-de-France. The “resident” (“riverain”) has outgrown the inhabitant. Curbs might slowly be replaced by “new urban commons” (“nouveaux communs urbains”), the association of curbs, sidewalks, and ground floor (rez-de-chaussée) into “city-floor” (“rez-de-ville”) (Mangin 2019).

18Moreover, projects of greening can be combined with classic utilities. “Curb-urinals” (“Uritrottoirs”) have been put in place on curbs of a dozen of cities in France and Belgium. These urinals are freely accessible, they are decorated by a planter box and produce bio-enrichment. These urinals are connected to a maintenance company, which can verify the level of filling of the urinal. The occupation of curbs is beneficent to the residents, the users, the public authorities, as well as the farmers who receive the enrichment.xv The greening of cities has inspired initiatives to collect and compost food waste. In May 2022, in Paris, Les Alchimistes, SPHERE, and JCDecaux installed five urban composting terminals. These composting micro-platforms are integrated in the urban landscape in the way they physically occupy the curb, but as they seem useful to the neighborhood (Paris and co, 2020).xvi Other public or associative services use the curb as a space to be occupied. Community fridges were first installed in Germany by the Foodsharing groupxvii and are now widespread around the world. In this case, curbs are occupied in a durable way to serve the residents but not in their mobility. These two examples reveal how the role of curbs is changing. As it changes, residents use it as an extension of their home. The curb can at the same time be a garden and kitchen. It is shared between neighbors as would be the indoor common space of a building. All of these occupations emphasize how the curb is a key resource for the various actors in the city, as it is composed of a variety of spaces (spaces in front of stores or building doors, parking and service lanes, curb-roadway line) that can serve differently those operators (cf. figure 1).

19Figure 1: the curb, a key-resource for city operators

The curb, a scarce space

20The intensification of uses is largely focused on the curb, revealing that the width of sidewalks is too small. Wills of expansion of sidewalks onto the road has been particularly suggested during the first months of the Covid-19 pandemic in Europe. Yet, are our sidewalks really too small? Considering that the physical surface street is limited in space, as long as the size of the given street remains unchanged.

21There are two dimensions to measure the size of a sidewalk: its length and its width. The length is fixed. The length of the curb depends on the length of the street. Therefore, the width is the only variable. However, when considering an existing street, its width is fixed. The enlargement of the curb can happen only at the expense of other lanes: the parking lane, the road, and the cycle path. These lanes often cannot be narrowed, they can only disappear, whereas the curb is a priori more variable. The width of the curb is used as an adjustment variablexviii. During the Covid-19 pandemic, however, curbs were temporarily extended in Europe for restaurants to expand the size of their terracesxix. In some cities, another adjustment variable is appearing, the parking lane (APUR 2019). The City of Paris has decided in October 2020 to suppress half of its 140,000 parking spots. This decision was featured as the will to dramatically limit the use of cars in Paris. It can also be understood as the intention to use a larger part of the curbxx. Online-delivery companies are artificially enlarging the size of curbs as they use the entrance of buildings as a logistics space.

22Because of its physical limitations and the growing number of actors to which the curb is valuable, the curb is scarcer and scarcer. For the moment, using the curb is free for private actors in most cases, especially when considering temporary occupations. However, curbs might soon be too valuable to be ignored by public authorities. Curbs would be scarcer and therefore more valuablexxi if they were limited in their access. Curbs could require conditions for private actors to use it for economic interests. Establishing conditions (paying a fee, establishing access hours…) could, as is examined later in the article, artificially limit the curb, in addition to its already existing physical borders. (Halpern 2020, Hao 2018, Marshall 2017, Smyth 2018)

23The clutter of curb spaces has boomed as a result of the digital transitionxxii. This clutter generates a growing competition for the occupation of physically limited space, the curb. This struggle for space has had a major outcome: “the modest curb” has become the most prized urban asset (Hao, 2018). From this observation stems the need to manage the curb as best as possible in allocating an availability of the curb to an occupation. This is how “curb management” emerged as a proper discipline in the United States and Canada. Curb management relies on the possibility of matching a need to availability on the curb in real-time. This dynamic curb management allows the curb to perform “more functions for more people at different times of the day” (Wiedenhaefer 2019). Curb management allows customized uses of the curb, such as dedicating one lot of the curb at one given moment to the dropping-off of people with physical disabilities. Whereas nowadays, vehicles for hire would drop their passengers off at one housing block from their real destination, it could be possible to choose a disability-inclusive drop-off zone, with a ramp to access the curb or access through an elevator rather than a stairway. “None of these advantages require new physical infrastructure. It is only about taking what is already there and digitalizing it” (Hao 2018).

Curb management in the various forms it can take displays a new perception of the street. It cannot be understood as an undifferentiated area, but rather as a stack of thin grids, referencing all the aspects of the public space; each spot on this grid is precisely identifiable and classified. The public space is pixelized. The most expressive image to describe such a change of paradox would be the grid of Battleship. The intersection of the abscissa and the ordinates tells the position of each “ship”, here each user of the space or an occupant of the curb. Therefore, unlike Battleship, time is a decisive dimension to consider when considering curb management. The spatial dimension of each point in the street is essential, while not sufficient to capture the nature of the occupation. To apprehend each point correctly, it is necessary to analyze each point at a given time t. The temporal dimension of the street is as important as its spatial dimension. Nonetheless, this grid-based analysis of the street differs from “tactic” urbanism. The Covid-19 pandemic largely contributed to the success of tactic urbanism (Pradel 2021), with requests for temporary street closures, or temporary extensions of sidewalks through the installation of café terraces on parking spots. Tactic urbanism encompasses the temporal dimension but is scaled upon days, weeks, or even months. On the contrary, curb management has a much shorter timescale. Modifications in the type of occupation at a given point in space happen at an intraday scale or even in real-time.

The new layer of the curb: data

24In addition to the exploitation of the physical surface of the curb, digital actors profit from a set of data. The first part of the article was committed to understanding the effects of digitalization on the physical layer of the curb, although digitalization also affects another layer of the curb, data, because those layers are indissociable.

Data and Cartography: who draws the map?

25As stated by Antoine Courmont (Courmont 2018), “the digital city is characterized by its “digital skin” (Rabari and Storper 2015), a layer of information, which has developed thanks to technological innovations in the ICT sector (mobile phones, IoT, etc.). The digital world stresses the point in which information technologies have become pervasive (Boullier 2016).” This digital layer of information should not be exclusively related to “digital cities” (“villes numériques”) or those cities that would engage in a process of transformation into a “smart city”. This layer exists in all cities. Indeed, every city is being transformed by the digital transition. More and more often, access to public space requires access to information.

26Since the development of smartphones, users of public spaces have changed their moving patterns. The way pedestrians walk, the pace at which they step one foot in front of the other, or the destination towards which car-drivers drive has changed because of the integration of smartphones into the everyday habits of almost everyone. Smartphones are also becoming the main access point to public space. Such layer of data is namely “operated” on by private actors of the digital world. As an example, Google has a key role regarding public spaces as the company is collecting, treating, and selling data, both with Waze and Google Mapsxxiii.

27When considering the access to data, the first issue at stake is the information on the access to public space. Google Maps is a perfect illustration of how local authorities must be attentive to the appearance of new digital actors. Google Maps provides an API (Application Programming Interface) for businesses, companies, or local authorities to integrate customizable interactive maps on their website. When it was first launched, this service was free below a certain threshold of use. This freemium business model granted Google an unavoidable position while suppressing the emergence of potential competitors. However, in the summer of 2018, Google restricted the free usage of its servicexxiv. Google Maps now puts forward the brands and businesses which are paying for their logo to be more visible on the application. The restriction displayed how public authorities had become dependent on these services. This example is a lesson for authorities to remain independent from new operators, which could master strategic components of urban planning, such as cartography or data analysis (Quest 2018). In Accra for instance (Ghana), SnooCode (a mobile application) generates a unique code for any placexxv. This technology functions thanks to the geolocation of smartphones and aims at replacing addresses, because the system of addresses is misfunctioning.xxvi

28With the collected and available data, Google Maps can draw a map according to its own criteria. In Brazil and Israel, the application Waze (Google-Alphabet) proposes a service for drivers to avoid areas, which are considered as dangerous. In addition, Google Maps highlights “areas of interest” on the maps of all cities of the world, putting forward centralities that do not necessarily match the perspective of public authorities (Vraiment Vraiment 2019). The curb is the space of collection of data. The actors succeeding in owning data can orient digital maps as they wish, in the most profitable manner.

Curb data management

29Curb data is also developing at a quick pace. Until recently, the understanding of curb data was poor. Within local administrations, curb data was split amongst different services (parking, traffic, fire and emergency services, logistics, network maintenance, street shops, bicycles, and carpooling). Such data was neither digitalized nor updated. However, it is now possible to “code the curb” (Smyth 2018)xxvii by producing a cartography of the curb including the location of curbs, the enforced legislation, and regulations (such as no-parking areas, delivery zones, bus stops, fire hydrants, etc.), traffic signs with their content, emergences (parking meters, cameras, bus stops, bicycles, or scooter parking spots, etc.), current usages (bicycle parking stations, temporarily authorized terraces, etc.), as well as real-time usages (parked cars, a vehicle dropping off a passenger, etc.). Curb data can be gathered by local authorities or private companies. Pebble (who took over Coord in January 2022) is a company created in 2018 after a Sidewalk Labs initiative. It is an example of a leading company in curb data production and gathering.

Curb management relying on curb data is benefitting operators for whom curb data is key (ITF 2022). Coord in 2021 sold data in the form of an APIxxviii, an interface, to “vehicles for hire” operators (Uber, Lyft, etc.), logistics operators, micro-mobility operators, etc. Data-based curb management also benefits the collective: vehicles would know exactly what parking spaces are available because this data would be integrated directly onto Waze or Google Maps. As a result, vehicles would not spend time looking for a free space, thus reducing congestion, improving air quality, and further reducing noise pollution. It must be stressed that naming the different physical parts of the street is central to optimizing the analysis of curb data. The difference between terms such as “curb”, “sidewalk”, “footpath”, “pavement” or between the “frontage”, the “façade” and the “building front” reflects a difficulty raised when trying to analyze curb data prospectively. Indeed, if foresight consists in naming things, then work must be accomplished to properly define the vocabulary of the street.

30The extension of curb management to components of the curb other than mobility would mean properly understanding the curb as a space of occupation (of clutters). Commonly, the curb is apprehended as a space, where mobility can be assessed. The curb is the space in which parking spaces, parked scooters, and bicycles can be found. It is also a space used by pedestrians when they walk in the street. However, the curb is also a resource for other private and public operators because of the layer of services, which is integrated into the curb, such as urban furniture (“mobilier urbain”), public water fountains, etc. The street is not solely a space of mobility, even though it remains one of the main (if not the main) characteristics of the sidewalk. The curb is also a space for recreational uses. The real-time pairing between the growing number of needs (in terms of types of uses of the curb) and the available offer of physical space is thus a way to optimize the use of the curb (Yu 2021). What do the users want the curb to be? What can it be at a given time? Matching the offer to the needs can be optimized thanks to curb management practices (ITE 2018, International Parking and Mobility Institute 2019, ITF/OECD 2018, NACTO 2017, National Center for Sustainable Transportation 2021).

Access to data and upcoming challenges

31The irruption of AR (Augmented Reality)xxix, which is a component of the digital transition, is also shaping the relation of users to physical space (Douay 2018). This change in the relationship can be considered both with public space and built-up environment. In the summer of 2016, the “Pokémon Go”xxx phenomenon created congestion in real-life public and private spaces. Aside from this example, AR is also being used by public authorities to promote some aspects of cities. The city of Montreal has created a digital application, Montreal in stories(“Montréal en histoires”) to encourage inhabitants and visitors to walk and creates animation in the historical center of the city at night.

32These evolutions in the relation pedestrians have with the public space have had impactful consequences on the physiognomy of streets. Thus, Google Maps uses AR technologies to display the inside and the upper floors of shops, whose owners decide to pay an additional fee. This technology and service might drive “shopkeepers and site managers to evolve in the way they show the inside spaces of their shops, in the way they offer the private spaces to the city and its passers-by (passants)” (Vraiment Vraiment 2019). In the future, as it is already the case in Japan, shops on the upper floors or in basements could be found and therefore accessed thanks to the location appearing on the smartphone, while being invisible from the street. The relationship between buildings and their ground floor or public spaces will inevitably change in the next decades, which will transform the physiognomy of curbs too.

33New actors of the digital world are constantly redesigning the way we orient ourselves, move around, and consume in the city. Even though these modifications yet remain modest and unobtrusive, they might have significant impacts on the shape of cities. “It is possible that the development of digital technology will contribute to transforming cities as systems of interaction and exchange multipliers. (…) We still know little about how social interactions, which are conveyed by search engines, change the staging of real urban life. For instance, the urban nightlife tends to organize through the existence of virtual communities, offering new access to various types of people via social media and gathering them in a real urban space” (Courmont et al. 2019), that is a physical space.

34During the Covid-19 pandemic, the access to data is less about the digitalization of space (cf. Coord, now Pebble) than it is about people circulating in that space. Some companies, which have developed systems of geographic information, are shifting towards the analysis of the users of the public space. Systems for verifying compliance with physical distancing measures could be an emerging economy, especially when considering that epidemics (or pandemics) might be more and more frequent in the future. Such systems rely on the massive use of artificial intelligence devices and therefore data. Societies such as Unleash Livexxxi, Esri, or Amazon have developed AI-based technologies to control physical distancing. Amazon uses this technology to control the physical distancing of its employees in its warehouses.xxxii

Arising concerns regarding curb governance

35Because of the digital transition, as well as the environmental transition, new actors are appearing on the curb. Some operators intervene on the physical layer of the curb, which belongs to local authorities, while more and more actors are profiting from the access to data. For now, access to data is poorly regulated. This lack of regulation allows for the multiplication of digital actors, who act as mediators with the users of the public spaces. Public spaces and urban services are organized in an ecosystem (Baraud-Serfaty et al. 2021). Some operators need to access the curb and this access is controlled by public authorities.

36One ought to differentiate three different types of actors, which are not positioned in the same way in the value chainxxxiii. The first type of actors, called hypervisors, are directly playing a role in urban governance. Hypervisors are the products of a contract between private (or semi-private) companies with local authorities. Local authorities, and indirectly local communities, are the main recipients of hypervisors’ services. Hypervisors are positioned upstream of local authorities in the value chain (unlike Google Maps-like actors which are positioned downstream, on the slot of “information”, closer to the final user). They provide information to the public authorities. Second, Amazon-like operators offer services to the inhabitants/users. To offer their services, these operators need access to the key resource of the curb. These actors will need to negotiate with local authorities to access the curb. Public authorities will therefore be considered key partners to Amazon-like actors. Last, Google Maps-like platforms are operating through the curb with advertisers, businesses, and users. Google Maps like many other digital platforms, have adopted a three-face model (Tirole 2018). Their objective does not rely on the access to the curb but on their ability to target clients through curb. Digital platforms are situated downstream of the value chain, close to the users. Because of their proximity to the inhabitants and the access to data, these platforms can bypass public authorities and thereby cause a rupture of the link between digital actors and local authorities.

37In addition, hypervisors refer to a “smart-city” type of approach to urban governance. Their organization is based on top-down and techno-solutionist reasonings. On the contrary, Amazon and Google Maps-like actors are “user-centric” in their conception of smart cities (Commission de l’éthique en science et en technologie 2016). On the “chain of value” of the services provided to residents (e.g., micro-mobility services, pick-ups, deliveries), these actors are positioned downstream, in direct interaction with the users.

Governance of actors born with the “smart city” concept: hypervisors

38In this section, we will focus on a specific type of actor, hypervisors. Hypervisors are not specific to curb management practices; however, their objective is also to favor optimized management of public space. The example of hypervisors is interesting for we can compare it to the positioning of private digital companies both towards customer targeting and value proposition making.

39The term “smart cities” would come from the 2008 IBM “Smarter Cities” initiative. This initiative aimed at making urban management more efficient in using technologies and data collection. Plenty of companies and IT services have followed this trend (Languillon-Aussel 2016, Peyroux 2019). Digital technologies are understood as technical solutions to practical controversies. The goal of smart cities is primarily the optimization of urban management in hybridizing urban systems, through the implementation of hypervisors. Hypervisors are models of urban management, which use "top-down”, techno-solutionist, and optimizing approaches. Hypervisors are conceived by private actors but are limited for they only serve public authorities. In La Défense, Paris’ central business district, a platform of hypervision was put into application. The platform manages “access security, road traffic, charging stations for electric vehicles, consumption of energy and water… Overall, thirteen different systems, viewable on a 2D/3D cartography (…), on three levels stacked together: roadways on the slab, in the tunnels, and the technical galleries. This hypervisor is a proper control tower of the district. It groups 15,000 pieces of equipment and is running 24 hours/day, 7 days/week through a security control station that links the hypervisor to other services. This system sends alert messages to managers when incidents are detected”xxxiv.

40Data generated from the analysis of the curb mobilities and “immobilities” is essential in the management of public spaces. In April 2019, the city of Dijon in France decided to put in place an urban pilot station (“poste de pilotage”) connected to various pieces of equipment in the public space of twenty-three surrounding municipalities. This device was set up by a consortium composed of Bouygues Energies & Services, Citelum, Suez, and Capgemini. Gathering data on the consumption of electricity and water is information to be used for private interests or to serve the management of a city. This hypervisor is considered the milestone of the “Smart City” initiative On Dijon. It is a command post, unique for it brings together five distinct domains of supervision and management in one location: the police, CCTV, security, traffic, and snow precipitation.

41This type of contract should be multiplied in the following years, even if it is still too early to have some perspective on the efficacy and convenience of such a management tool, and even if these actors are often criticizedxxxv. It is critical to emphasize the need for companies to finance the entire system.xxxvi Therefore, as public authorities can become dependent on digital services, they can also become dependent on the service provider, which would have financed the hypervisorxxxvii. The hypervisor in La Défense is controlled by one single company, Vinci Energies, whereas the trend accentuates the fact that consortia are much more frequent in the establishment of such device of management, as is the case with the hypervisor in Dijon. In China, digital platforms, such as Alibaba, are providing services similar to those of hypervisors, called City Brain. It was implemented in 2016 in Hangzhou.

42Real-time management is a crucial dimension for “urban monitoring”. Such a device relies on the disposition of sensors in the city to measure and gather a set of urban data (noise pollution, air quality, the filling rate of waste containers, watering of green spaces, etc.). The goal of this monitoring is to improve the quality of the services corresponding to the measured data, for instance in optimizing waste collection depending on the location of the most filled containers.

Governance of Google-like actors

43The digital transition has created a variety of street operators. The actors of the digital world can also be platforms, but they are also startups or IT companies (Courmont 2018). These operators are among those who are the quickest to evolve, partly because they must adapt to an always-changing technological environment. Indeed, the three laws of the digital economy above-mentioned may equally encourage the development of some operators and put an end to some others in the way that some free-floating bicycle companies have disappeared as suddenly as they appeared. Uncertainty and constant evolution of the actors of the digital economy are also a factor of their power: “To continue to grow and become a "super-app", Google will have to persuade the competition authorities that its successes are not abuses of power. But in the United States, the tide is turning against the new giants of the Internet, and their "winner takes all" strategy is starting to turn against them. Like Facebook, and to a lesser extent Apple and Amazon, Google is currently the subject of several antitrust investigations, led by the Federal government and a coalition of states" (Georges, 2020a). On the one hand, these digital giants have access to the curb through its data and not its physical space, therefore public authorities struggle to regulate their activity. Moreover, the freemium economic models allow these companies to grow rapidly and therefore to be untouchable because of their unavoidability. On the other hand, curb data is not the property of those companies. Free access to the collection of curb data allows cooperative projects, such as OpenStreetMap, to develop alternatives to widespread (inevitable) digital tools, here to Google Maps (Choplin et al. 2019).

44Curb management can be a powerful tool to optimize the way the occupation of the curb is conceived and used. One or several actors must take responsibility for putting in place effective management of curbs. These actors will be responsible for matching the offer to the demand in terms of curb occupation. This match shall not be exclusively technical but is political in the arbitration decision-making process. Curb management necessarily results in prioritizing some occupations over others. Nowadays, two types of actors are willing to take an active role in curb management. On the one side, local authorities want to play a role in curb management. Since 2015, the city of Washington D.C. has identified information on delivery areas and put in place a dynamic pricing system for those areas. Cities can rely on private actors, such as Populus, to obtain data and/or to put in place innovative solutions to optimize curb management. Populus gather data on parking locations and patterns of occupations. After analyzing these data, the company will advise the city to optimize the access to curbs to suit all needs. On the other side, many private actors are taking positions on curb management practices. Traditional urban actors, such as Siemens, as well as digital actors, such as Sidewalk Labs or Pebble, are competing to gain control over the management of curb. These platforms are considered a threat by public authorities for they are becoming essential to most habits of the daily life of residents. Nowadays, such actors are not part of a contractual relationship with the public authorities, but one could imagine a third way in which this would be the casexxxviii.

45Operators of curb management are owners of the data they gather from the curb. These operators can work for municipalities but can as well sell those data to any of their clients. According to SharedStreets, “cities should be owners of the curb’s inventory data. In this way, no company could “hold” a portion of the curb, (and) determine the way it (the curb) is priced or controlled its access”.

Curb governance of Amazon-like actors

46The curb should not necessarily be understood as an object of regulation. On the contrary, the curb can be an efficient regulation lever. Public authorities must be aware that the occupation of curbs constitutes an immeasurable and unavoidable resource to the economic well-being of a plethora of private actors. Without access to the curb, Amazon, Uber, or Lime would have extreme difficulties selling their services. The access to curb is crucial to these digital actors, but it is also needed by traditional actors (physical shops). The curb is most of the time public property, therefore public authorities have the right and capacity to govern these private operators. Local authorities can implement regulations on the curb. In May 2019, the City of Paris compelled free-floating scooter companies to agree upon a “charter of good behavior” (Dezobry 2020). To implement regulations, local authorities must own these spaces. It would be impossible for a municipality to regulate a garden on the frontage of a building as if it was part of the curb. In a context of shrinking local budgets (as is the case in France), local authorities often consider the curb, and broadly public spaces, as costly infrastructures, both in terms of production and management. From this assumption, it is tempting to have the urban development operations carried out by contractors and to transfer the ownership of the space to an association of co-owners. This is often the case in the realization of macro-lots. This trend is mainly present on smaller secondary streets, not structuring axes. Nonetheless, there is a paradox in the way public actors get rid of the most valuable and most strategic space of the city (Wiedenhafer 2019, Clewlow 2020b, Baraud-Serfaty 2020c).

47Public authorities must change their paradigm when considering the curb. Curb must be understood as a strategic asset in the city, whether it is monetized and regulated or not. Still, putting a price on the access to the curb remains delicate if public spaces are considered free and open access. On the contrary, the establishment of terraces is subject to specific fees. Public authorities should seize this question of the pricing of curb occupation, not simply because it is an accessible source of income. The real questioning is about letting private actors use the curb massively for their interests without compensation for the use of this space. Curb management practices have also shown that pricing itself can be dynamic and adapt to the type of actor, the nature of the use, and the duration and size of the curb occupancy. Pricing can be applied to operators who use the curb as a valuable resource, and not to regular users and inhabitants. Raising the question of the pricing of public space also raises the question of determining what is and should be free of access. Originally, free use of public spaces by users was based on its payment by taxpayers. However, because of the digital transformation of cities and the widespread use of freemium business models, free use is only possible thanks to (or because of) advertisement. The pricing of public spaces must go hand in hand with legal evolutions and a deep reformation and redefinition of the nature of public spaces to integrate digital actors, as well as anticipating the emergence of newer actors.


48The digital transformation of urban spaces has changed the role and the importance of the curb in the city. Whereas the curb was understood through its mobility component, the emergence of digital actors has stressed the scarcity of its occupation capabilities in terms of immobility. The scarcity of the space of the curb is revealed both in its physicality and the collection of data. This scarcity, in addition to making the curb a key resource, is putting forward its value. Many new actors need access to curb’s space, but this access is limited. Digital transformation of curbs is pushing towards more regulation from public authorities as well as an overall improvement in the way curbs are managed (Ville de Paris, 2022).

49The curb should not be a space dedicated to regulation only, for it is a revealing of urban transformation under the effect of the digital transition. One might consider the curb as a place of observation to analyze and understand the dynamics, processes, and types of actors at stake in the digitalization of cities. These digital newcomers do not yet have a fixed business model and strategy. It is therefore from the curb that most of these transformations take place. As are digital and energetic governances or the environmental transition, the access to the curb is also becoming a gateway for private actors to integrate themselves into the economic landscape of the city. Once integrated into the curb, which is integrated into the public space, any actor can seize greater opportunities in the physical and digital layers of a digitalized city. When looking at actors of the digital world, failures, and successes in their integration into the digital economy of a city can be assessed only through their capacity to occupy the curb and use it as a resourceful space.

50Another aspect to take into consideration is that the curb is in fact expanding. The “right to the city-floor” (“droit au rez-de-ville”) aims at enlarging the curb by considering the ground floors of buildings as the continuation of the street (more specifically of the curb)xxxix. These inside spaces should be seen more as an inside portion of the street, rather than the base of the building itself. This expansion of the curb is a redefining of the street: from the space between two frontages (“façades”) to the space between the walls of facing buildings (“pieds d’immeuble”). During the Covid-19 pandemic, queues in front of shops have overflown onto public spaces. The lengthening of queues has contributed to the growing permeability between the private space of the shop and the public space of the curb. This permeability between public and private spaces at the front door of buildings is also demonstrated through the development of logistics in supposedly private spaces. Digital delivery companies, as well as virtual restaurants, are using ground floors as if they were logistics spaces. Expanding the curb towards the inside of buildings is telling of the scarcity of the available lots on the curb, even though digital platforms need smaller and unmarked spaces. The blurring is increasing between real estate space (mostly indoor and private space) and public space (mostly outdoor and public space).

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Electronic reference

Isabelle Baraud-Serfaty and Nathan Benamouzig, The new value of curbsArticulo - Journal of Urban Research [Online], 22 | 2021, Online since 03 February 2023, connection on 27 February 2024. URL:; DOI:

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About the authors

Isabelle Baraud-Serfaty

Consultant in urban economy, teacher at Sciences Po, Paris

Nathan Benamouzig

Graduate student Sciences Po/UCLA.

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The text only may be used under licence CC BY-NC-ND 4.0. All other elements (illustrations, imported files) are “All rights reserved”, unless otherwise stated.

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