urban transit

Is digital really helping to end urban congestion?

"Cities are fighting traffic jams with Big Data", "Applications to beat traffic jams on the road", "The end of the galley": digital technology has arrived in the cities with its share of promises. Optimizing the city, making it smarter. In every major function of the city, digital technology has been brought to play a fundamental role. But what about mobility? While we have seen the development of new transport offers, the announcement of the disappearance of the car and traffic jams in the city has not yet come to pass. Worse, digital technology seems, in some respects, to have contributed to urban congestion. This is the observation of the think tank La Fabrique de la Cité in its report on congestion and digital technology, Ending (the end of) urban congestionpublished this Thursday, April 11.
The passage of cars through the winding narrowness of the streets, the din of a stuck herd would snatch sleep from Drusus or from sea calves. ...] We who hasten ahead are hindered by the flood that precedes us, the mass of people who follow us in great crowds press us to our loins; this one hits me with an elbow, another hits me with a rough beam, this one hits my head with a joist, this one again with a barrel.
Satires III - The Embarrassments of Rome, Juvenile, 110 ".
Rn the sunshine again: in the first century AD, Juvenal already perfectly defines urban congestion as the result of an imbalance between available space and traffic flow. Inherent to cities, congestion has serious consequences. Firstly, environmental consequences, since the immobilisation of several thousand polluting vehicles has consequences on CO2 emissions. In the United States, congestion alone is responsible for an additional 25 billion kilograms of CO2 emissions. (1). Economical then, since in France, the cost of time lost in traffic jams represents nearly 3.3 billion euros. (2).
To this must be added the health risks linked to fine particle emissions and the risks of increased stress and anxiety for urban dwellers: in metropolises, where city dwellers generally spend more than one day a year stuck in traffic jams, urban congestion is cited as one of the main stress factors by the working population (25%). (3). A survey conducted by Waze in October 2018 indicated, for example, that for 79% of Israeli drivers, traffic jams were the most important cause of daily stress.

The "bottled city": a pleonasm

This century is the century of individual mobility: the car, which is more flexible and faster, is becoming the primary mode of transport for everyday journeys. (4).
To solve "the traffic problem"... (5) In cities sized for travel on horseback or on foot, space must be opened up. The twentieth century consecrated "the passage from pedestrian metrics to automobile metrics". (6) The streets widen, the number of parking spaces multiplies, the city spreads out in a centrifugal movement allowed by the automobile. In spite of these transformations, congestion remains, survives and becomes... automobile to such an extent that in 1908, the president of the Congress of Tourism suggested that "... the city should be transformed into a city of cars...". channel "In 1921, the French Highway Code was created and finally enforced, thanks to red traffic lights, right-of-way, and the creation and enforcement of the Highway Code.
Today, the space open to the automobile in the past is gradually closing. Cities are moderating car traffic in favour of new modes by reducing the space dedicated to the car (lanes, parking lots). This paradigm shift is the result of a web of considerations that combine the fight against congestion with the reduction of pollution, the desire to reduce car use and the promotion of multimodality, especially more virtuous modes (cycling, walking, public transport). Reducing speed limits, congestion charging, traffic restrictions and the development of public transport are all solutions implemented by cities in an attempt to reduce the increase in traffic congestion.

What if the long-awaited miracle solution comes from the digital revolution?

In 2005, the first bricks of what would later become the "smart city" embodied the utopia of the controlled, predictable and regulated city, a city in which human intelligence is fading away in favour of intelligence allegedly obtained through digital tools.
For digital has enabled cities to enter the era of optimizing existing infrastructures: mobility remains the favorite playground of digital platforms and congestion, their best enemy.
This new era was therefore going to be able to revive many battles such as the fight against the famous traffic jams, a problem inherent to large cities and the source of nuisances that affect accessibility, the environment and the quality of life in cities. And for good reason: thanks to its ability to aggregate a large amount of data, create new services and build mobility platforms, digital technology promises to ease congestion in cities by enabling users to better plan their journeys, avoid traffic jams and abandon their personal cars.

The digital city to the rescue of the congested city: what promises?

However, since their appearance about ten years ago, these digital tools have not made traffic jams disappear. Paradoxically even, digital technology has led to giving a new raison d'être to the car in the city by making it available and more competitive. Meanwhile, metropolises are becoming ankylosed and some inhabitants of the most outlying areas, captive to the automobile, see their mobility degraded, sometimes forcing them to demobilize.
For Antoine Piconprofessor at the Graduate School of Design of Harvard University, the last few decades have seen the passage of the " city of flows and networks ", as it has been known since the 20th century, to the " city of occurrences ». The latter would be based on the capacity of cities to record more and more events. Each of these occurrences, or data, represents the city differently.
In the digital city, the plan gives way to the scenario. Data, artificial intelligence, sensors... Behind the digital are actually many technologies and techniques. They enable private actors in the city as well as municipalities to be able to process a very large amount of information in real time. Thanks to these new acquired capacities, it is hoped that the city will be more fluid and liveable.
These promises are based on three levers that digital technology seems to be able to activate or facilitate: developing knowledge of mobility, providing better information to users and, lastly, setting up an intelligent and responsive real-time transport system.
The promises of digital technology are numerous when it comes to moving around more simply. The players in this new economy have been the first to relay them, using many superlatives in the process. In response to the traffic jams of the past, they propose to avoid them with intelligence (" outsmart traffic ", Waze); they intend to solve the intermodality complex by simplifying the city (Citymapper); finally, while the service provided by historical modes of transport is gradually deteriorating, they promise comfort and efficiency at an affordable price (Uber). Behind these words are promises of services deployed by digital players. Focused on the objective of simplifying mobility by making it more fluid and less complex, they seek to renew the travel experience. Digital has made its mark on the mobility landscape, to the extent that these new services are perceived as essential by city dwellers, vectors of innovation and change that would necessarily go in the right direction.
Among the many services developed thanks to digital technology, Europeans value the indispensable nature of paperless payment services (62%), journey planners promoting intermodality (73%) and passenger information (77%). (7). Predictability, real-time information, aggregation of data from a greater number of players... The innovations brought by digital technology have made themselves essential in the collective imagination in a very short time.

Knowledge, information, intelligence, but the problem remains...

To understand why digital technology has not and will not solve the problem of congestion in cities, we must go back to the very cause of congestion: an economic imbalance between the supply of infrastructure and the demand for mobility. Behind the effects of the announcement of digital services aimed at reducing urban congestion, there is a reality: nothing seems to be able to stop the slow progression of congestion in cities, not even the most intelligent technologies. This calls for the identification of proven and unproven solutions to reduce congestion.
Far from being resolved, congestion seems to be increasing in many cities (8). The review of the INRIX Global Traffic Scorecard, the highest ranking of cities according to their congestion, no real global movement to reduce congestion emerges. What's more, Los Angeles, Moscow and New York, cities that are already very much involved in the digital revolution, have formed a stable top trio for several years: the world's most congested cities. It is therefore becoming urgent to reexamine the link between digital and mobility.

A paradox of modernity: when digital increases congestion

More than ever, traffic congestion is a far cry from the initial promises of digital technology in terms of reducing congestion. Disillusionment is high, equal to the disconnect between the promises and actual achievements of digital technology. Maximizing travel time - in the economic sense, in order to derive the greatest benefit from it - does not in itself make it possible to curb the trend increase in congestion. That these services have improved or even transformed the user experience at the micro level is undeniable. These services enable city dwellers to make informed decisions, to move around without constraints.
However, the overall traffic situation continues to deteriorate with few exceptions. (9). According to data collected by the TomTom application, the congestion rate in European and American cities has increased by 1.8 and 1.5 points respectively. The subject of improving the situation at the macro level therefore remains unresolved.
What if this congestion is exacerbated by digital? Far from having improved the situation, digital technology may have contributed, in some respects, to congestion. Route planners, by indicating the most direct route to a destination, actively contribute to the overall reduction in the number of kilometres travelled by car ("Vehicle Miles Traveled") and VTC's services contribute to its increase. However, although they have different effects on traffic, they both contribute to increased congestion. (10). Rewarded for their efficiency, they allow users to do without their personal vehicle in urban centres and thus contribute to the demotorization of city dwellers. These digital companies have gained this efficiency and position as key players in mobility in the field, notably by making a very large number of vehicles available to reduce waiting time and make the service more reliable.
Between 2015 and 2016, the city of New York experienced, for the first time since 2009, a decline in public transport ridership (bus and subway), while Uber et al. tripled their passenger numbers over the same period. Observed in major American metropolises, this trend is particularly strong in dense urban areas for off-peak travel.
By now competing with historical modes such as public transport, walking and cycling, these new digital services have paradoxically contributed to increasing urban congestion. This phenomenon constitutes a real transformation of urban travel patterns: the transfer of part of the demand for mobility to these new digital modes.

Congested city or congested society: space, time... and us...

A bottleneck occurs primarily because the ratio between capacity and demand becomes unbalanced. And cities are areas that are conducive to congestion... The effective and efficient functioning of our societies implies the synchronisation of working hours. Thus, working people and students must be in the same places and at the same time to be able to interact. This necessity imposed by our societies leads a majority of city dwellers to move around in similar time windows: 7:00 am to 9:00 am and 4:00 pm to 6:00 pm. In addition, the spatial concentration of employment, increased by metropolization, contributes to reinforcing the use of road networks around employment centres.
Several factors explain this increasing reliance on long-distance commuting. Firstly, the phenomenon has been facilitated by the presence of transport networks over these long distances (suburban trains, buses) and by the reduction in the cost of car use. The increasing acceleration of transport has made it possible to push back urban boundaries and for city dwellers to live further away. In addition, this increase in travel distances has become a means of coping with tensions on the labour market, rising land values and disparities in the attractiveness of the regions. (11). Far from a re-ruralization of society made possible by the computer and the Internet, society remains urban.
For Edward GlaeserThe reason for this is that the city is not just a place to work," he says. It is also a place of consumption in which city dwellers enjoy spending time. (12).
Contrary to what was envisaged with the advent of information technology, cities have gradually spread out, while daily journeys are made over ever greater distances and durations. City dwellers tend to become more mobile.
The phenomenon has become particularly acute in Europe in recent decades. (13). In France, commuters' commuting distances (14) have lengthened by an average of 1.6 km between 1999 and 2013. (15) The same is true in the United Kingdom over the period 2001 to 2011. A study conducted by the Urban Sociology Laboratory (LaSUR) of the Swiss Federal Institute of Technology in Lausanne (EPFL) indicated that in 2015, between 11% and 15% of European workers aged 25 to 54 could be described as "highly mobile". (16). In France, the share of journeys of less than 10 km decreased while the share of those between 20 and 50 km increased. Over these longer distances and as one moves further away from urban centres, the car remains the main - if not the only - mode of transport, a mode which, when under-optimised, contributes to a disproportionate use of roads and to the emergence of traffic jams.
This excessive demand leads to congestion when there is overcapacity on the network. Due to too high a concentration of traffic, the optimum traffic speed can no longer be achieved. (17). The main cause of this phenomenon is the sub-optimal character of the individual car, which is often pointed at. In fact, private cars have a relatively low occupancy rate in relation to their capacity. In Europe, the vehicle occupancy rate fell between the 1990s and 2005 from 1.65 to 1.45 passengers per vehicle. (18).
Conversely, the number of kilometres travelled per passenger increased over the same period: from 45% in Germany, 28% in France and 15% in the United Kingdom. (19). In summary: the number of vehicles on the roads is increasing faster than the number of people transported.

What actions can be taken?

Unlike a true common good, whose resource is limited, the road network is extensible. Nevertheless, once its extensibility has been reached, either because it is spatially impossible to build more roads or because the resources necessary for its construction are lacking, the road network can be considered a finite resource and therefore a common good for the non-concession (and non-paying) network. On these roads, traffic jams are a perfect example of the "Tragedy of the Commons".
Theorized by Hardin in 1968, this phenomenon is defined as the overexploitation of a common and limited resource and from which no economic player competing for its consumption emerges as the winner. In other words, in a traffic jam, everyone is a loser. This theory is useful for thinking about how motorists can change this situation and make better decisions collectively. (20).
If urban congestion does indeed manifest itself in the momentary and recurrent immobilisation of many vehicles on urban roads, it can be analysed in two quite distinct ways. Seen from the perspective of urban travel, traffic jams illustrate the inadequacy and inappropriateness of metropolitan mobility policies, as city dwellers lose tens of hours - even a hundred in the most extreme cases - stuck in traffic jams every year. But congestion is also, like the economist Anthony Downs a direct manifestation of the good economic health of cities. Thus, if traffic jams are a source of nuisance for cities, they are also a manifestation of their attractiveness. The possibility of this dual interpretation of urban congestion makes its resolution all the more complex: how to arbitrate?
Urban congestion is likely to survive the digital solutions that were intended to end it. In order to break the current deadlock in which our cities find themselves and from which only urban congestion emerges as the winner, it is necessary to go beyond the question of the role of digital players alone in reducing congestion and to see how digital could be a privileged support in the development of more efficient tools (pay-per-use, etc.).
Teleworking, construction of additional lanes, congestion charging...: between apparent short-term solutions and medium-term aporias (construction of new lanes), substantive multi-actor actions as such complex to implement (changing social rhythms) and technically but politically difficult effective measures (making the motorist pay), congestion reduction strategies go well beyond the digital issue. As pointed out by Martin Wachs, a professor at Berkeley University, "Congestion is always described as a major problem that needs to be solved, but it is unacceptable to use the most effective solutions" (21).
The real issue is therefore not so much the disappearance of congestion as its relative control, in which digital technology must find its place and, as Downs invites us to do, to investigate the most effective tool to date in reducing urban congestion: the taxation of mobility, consistent with contemporary environmental and spatial issues. What could be better than current technologies (GPS, pay-per-use) for which digital technology is a preferred medium?
Source : Camille Combe - Cécile Maisonneuve The City Factory (Edition: Marie Baléo)
(1) Eli Meixler, Singapore is Banning Additional Cars on Its Roads as the City-State Runs Out Of Space, Fortune, October 24, 2017 [Online] (Accessed October 24, 2018)
(2) Expressed in number of vehicles using the infrastructure.
(3) Richard Dowling, Alexander Skabardonis, Michael Carroll, Zhongren Wang, Methodology for "Measuring Recurrent and Nonrecurrent Traffic Congestion, Transportatio Research Record": Journal of the Transportation Research Board, 1867: 60-68, 2004.
(4) INRIX Global Traffic Scorecard (Accessed February 9, 2018)
(5) Ministère des transports du Québec, Travel induction and the Montreal area transportation model, September 16, 2002 (Accessed June 6, 2018)
(6) Bruce Schaller, Empty Seats, Full Streets : Fixing Manhattan's Traffic Problem, Schaller ConsultingDecember 21, 2017  
(7) Frédéric Héran, De la ville adaptée à l'automobile à la ville pour tous. The Parisian example, in Déplacements. Architectures du transport, territoires en mutation, Anne GRILLETAUBERT, Sabine GUTH (dir.), Recherches/Ipraus, Paris, 2005, pp. 173-186.
(8) NRIX Global Traffic Scorecard  (Accessed February 9, 2018)
(9) Tomtom.com, TomTom Traffic Index, Measuring Congestion Worldwide2016 (Accessed September 17, 2018).
(10) In just a few years, chauffeured transport companies have established themselves as key new players in urban mobility. In New York, in barely three years, Uber and Lyft, the leading figures of this new economy, have managed to surpass the emblematic "medallion taxis" in number of runs.
(11) Emmanuel Ravalet, Highly mobile or highly sedentary?, Mobile Lives Forum - Preparing for the mobility transition, February 18, 2014
(12) Greg Rosalsky, The Economics Of The Office: Why Do We Still Commute?, Pacific Standard, 30 October 2017
(13) Fabrice Breithaupt, La grande mobilité liée au travail est un phénomène de société, Interview with Vincent Kaufmann, Sociologist, EPFL, La Tribune de GenèveNovember 19.
(14 ) Selon l'INSEE, un navetteur est un actif occupé non travaillant dans sa commune de résidence.
(15) Institut national de la statistique et des études économiques, De plus en plus de personnes travaillent en dehors de leur commune de résidence, INSEE Première n°1605, 30 June 2016.
(16) "Large mobile" means a person who spends more than two hours a day commuting to work on average.
(17) Gaële Lesteven, Les stratégies d'adaptation à la congestion automobile dans les grandes métropoles. Analysis based on the cases of Paris, São Paulo and Mumbai, Geography, Université Panthéon-Sorbonne - Paris I, 2012.
(18 ) European Environment Agency, Occupancy rates of passenger vehicles16 December 2008
(19 ) 13 Kurt Van Dender, Martin Clever, Recent Trends in Car Usage in Advanced Economies - Slower Growth Ahead?International Transport Forum, September 2009
(20) Paul Minett, Are Predictable Traffic Jams a 'Tragedy of the Commons'?,Move Forward, Infrastructure, September 11, 2015 (Accessed September 14, 2018)
To go further :
– Cities and People: An Investigation into a Global Way of Lifeby Edward Glaeser, Paris, Flammarion, 2011, 364 p. (Translated from the English Triumph of the City: How our Greatest invention Makes us Richer, Smarter, Greener Healthier and Happier, the Penguin Press, 2011)

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