The groundbreaking analysis of more than 30 billion location-based steps, jointly conducted by Emerton Data and WeWard, provides a factual insight into the various mobility phenomena observed since the announcement of of the containment in France.
Article realized in May 2020, republished in summer 2022
"The goat grazes where it is tied" (Cameroonian proverb) ... with the same number of steps
The unprecedented analysis of more than 30 billion geolocated steps, jointly conducted by Emerton Data and WeWard, provides a factual insight into the various mobility phenomena observed since the announcement of the containment in France. The results presented in this report are used to inform discussions on the implications of a generalized and uniform containment on the territory, and on the implementation of decontainment or a new containment. The announcement of the confinement, made a few days before its effective date, generated numerous long-distance pre-confinement trips: about 20% of the French population moved from one department to another, mainly in departments adjacent to their place of residence. To what extent does this massive displacement of the 18-45 age group concern family reunification with relatives vulnerable to covid-19? A more detailed analysis of local trips (less than 1 km) shows that the French population, especially in cities, quickly returned to almost normal walking activity during the period of confinement. After having briefly dropped to 2000 steps per day, the pedestrian activity returned at the end of April to a level almost equivalent to the one observed before the confinement, i.e. 5000 steps per day in Paris (against 6500 in normal time), in one of the most densely populated cities in the world (20000 inhabitants / km2), and 5500 steps per day in the rest of France (against 5500 in normal time).
What is the health impact of this level of travel in a densely populated area? What is the relative impact compared to other modes of individual travel in an unconfined context, for example with the continuation of professional activity?
In the context of the COVID-19 pandemic, many countries, including France, have chosen to adopt a containment strategy with the objective of drastically restricting the movement of their population.As the progressive decontainment approaches, WeWard and Emerton Data have conducted a study on the mobility of the French population. This report is based on anonymized data aggregated at the departmental or Parisian district level, from users of the WeWard application. More precisely, the results presented are based on more than 40 billion steps taken by 140,000 users distributed throughout the French territory, with the particularity of being composed of individuals who are rather urban and in the 18-45 age group.
While containment reduced the proportion of daily trips of more than 10 kilometers by a factor of 8, trips within 100 meters of the containment site increased by a factor of 2.
From the first days of the confinement (end of March), the proportion of long distance trips (more than 10 kilometers) was divided by 8, going from 23% to 3%, while the proportion of short distance trips (less than 100 meters) was multiplied by 2.2, going from 30% before the confinement to 67% at the end of March. In addition, individuals usually moving more than 5 days per week beyond 100 meters, moved outside this radius only 2 days per week on average during the confinement. From April onwards, the analysis shows a resumption of travel, with an 8 point reduction in the proportion of individuals staying within 100 meters (from 67% at the end of March to 59% in April). The resumption of trips of less than one kilometer is particularly high in the less densely populated departments such as Corsica, Ariège or Lot.
The percentage of individuals confined within 100 meters increased sharply from 33% to 67% at the end of March and then to 57% in April. However, pedestrian trips returned to their usual level of around 5500 steps/day during the confinement.
This is true for the entire country, although there are significant differences between departments. Paris usually has 27% of individuals staying within a radius of less than 100 meters, compared to 33% for the whole of France.
Parisians have thus reduced their trips even more drastically to reach the same level of confinement as in the rest of the territory, at 67%, with marked disparities in certain districts.
The proportion of individuals staying less than 100 meters from their home is lower in departments with lower density, such as Lot (53%), Ariège (55%) or Haute-Corse (55%). Beyond the proximity to the home, the confinement had an impact on daily physical activity, measured by the number of daily steps. In normal circumstances, the panel took 5500 steps per day.
At the end of March, the number of steps per day fell by -61% to 2100 steps per day, then rose again and returned to almost normal at the end of April, in the middle of a strict confinement period. In Paris, the drop in the number of daily steps at the end of March was even more marked (-71%), with a more moderate return to normal at the end of April (-23% compared to only -2% for the whole territory).
The announcement of the containment measures generated a significant number of interdepartmental movements, with 20% of individuals concerned. Paris is the main source of departure and Lyon the main destination.
In addition to the containment and social distancing measures, the French government has recently implemented a departmental management of the epidemic. Interdepartmental mobility is subject to restrictions during the progressive decontainment: travel limitation to 100km and specific measures according to active traffic and hospital saturations. The study on WeWard data confirms the phenomenon of interdepartmental travel, observed by many French residents who have temporarily changed their place of residence. This concerns 20% of the French population, 13% of whom have moved to another department.
Not surprisingly, the most urban departments (Paris, Rhône, Bouches-du-Rhône, Gironde, Haute Garonne, Nord, Loire-Atlantique) account for the highest numbers of departures and arrivals. Paris is the main origin of departures, accounting for 12% of national departures among 18-45 year olds, and representing 31% of Parisian residents. Lyon, on the other hand, is the city with the most arrivals (4% of all arrivals in France). The departments hosting the ski resorts were emptied with a high percentage of departures, such as Savoie (43%), Hautes-Alpes (41%), Hautes-Pyrénées (27%) or Haute-Savoie (18%). Conversely, Corsica did not experience any notable movements (less than 5% of departures and arrivals observed).
However, most of these trips are limited to the neighbouring departments, often less than 100 km from the usual place of residence.
Departures from Île-de-France are mainly to neighboring departments, accounting for 52% of the trips observed. They also concern the other large cities for 29% as well as the coastal departments accounting for 16% of trips.
As for departures from other large French cities such as Lyon, Toulouse, Lille, Marseille, Bordeaux or Nantes, the destinations are concentrated in the departments in the immediate vicinity. To go further, it would be interesting to explain this phenomenon by more precise age segments (for example, by analyzing students aged 18-25). Finally, the main destinations for departures from Savoie and Haute-Savoie are Lyon and Grenoble.