Deconfinement is fast approaching. From May 11, it will again be possible to move freely, with the notable exception of "trips more than 100 km from home". During the presentation of the deconfinement plan to the deputies, last week, Edouard Philippe announced that " travel more than 100 km from home ... will only be possible for a compelling, family or professional reason".
Read also: How can I easily calculate a radius of 100 km around my home?
Important clarification, it will be possible to cross departments but also to go to a department classified red on the deconfinement map, even if ours is green. And vice versa. But why an area of 100km and not 50 or 200km? The government remains elusive on the issue. Obviously, the main issue is to limit the circulation of the virus, and therefore the movement of French people. However, there does not seem to be any real calculation justifying this choice. “The 100 km area is, in a way, the living area. This includes the movements of daily life. It is an area that allows you to do your shopping, to do administrative procedures at the prefecture for example, to go to work… ” , one assures however of the side of Matignon.
It is true that mobility surveys, in France or abroad, often use a 100 km threshold to distinguish local mobility and long distance mobility. "This threshold makes it possible to encompass the majority of the usual trips by French people who are made within this radius," specifies Anne Aguilera, researcher at the City Mobility Mobility Laboratory. I imagine that the government's idea is therefore to guarantee normal activities and limit more exceptional travel. ”
"A partly arbitrary choice"
According to the latest national transport and travel survey, published in 2008, local mobility corresponds to "all trips made within a radius of 80 kilometers around the home and on the national territory". In 2008, it represented almost 99% of French trips. For the next study - carried out between 2018 and 2019 and the results of which will be published soon - the threshold for local mobility will be minus 100 km.
"Concretely, this includes everyday travel, that is to say health, administrative, sociability or leisure, shopping, work and schooling," adds Richard Grimal, researcher within the ESPRIM team. at the Center for Studies and Expertise on Risks, the Environment, Mobility and Planning (Cerema). A radius of 100 km therefore largely encompasses all these distances. For example, according to INSEE, in 2015, 14% of employees took their car every day to go to their workplace located more than 25 kilometers from their home.
"The selected threshold is a partly arbitrary choice even if it more or less covers what was called urban and intra-urban mobility", notes Richard Grimal. "These 100 km do not represent much ," says Brigitte Baccaïni, Inspector General of the Administration of Sustainable Development. Mobility is never 100 km, daily journeys are much lower ”. According to the last national survey, the French traveled indeed 25.2 km per day when the Territorial Observatory indicates in an analysis published in 2019, that the French, outside Île-de-France, walk an average of 36 km in one day .
100 km as the crow flies or by road?
"On the contrary, for journeys over longer distances, the French go well beyond 100 km," says the specialist. For holidays, for example, almost half of motorists travel more than 500 km, according to polls. The government clearly wants to avoid a rush on the roads and this delimitation of the 100 km makes it possible to avoid long journeys, especially when approaching long weekends like the ascent. ”
An unknown remains, however. The government has still not specified whether it is an isodistance, also called distance traveled by roads, or a radius as the crow flies, that is, in a straight line. The difference is not trivial. "The road is longer than the crow flies," clarifies Brigitte Baccaïni. The distance traveled by road is given on the car counter or on the smartphone. That as the crow flies can be calculated on sites as was the case for the kilometer authorized for physical activity ”. The latter is thus more advantageous because it makes it possible to cover more distance, as shown by the following maps produced thanks to the OAlley site. The circle represents 100 km traveled as the crow flies. If for Parisians, the result is substantially the same, the inhabitants of Privas (Auvergne-Rhône-Alpes) will have access to Saint-Etienne and Avignon as the crow flies but not by road.
100 km from the premises of Figaro, in Paris. Map produced on the OAlley site
100 km from Privas, in Auvergne-Rhône-Alpes. Map produced on the OAlley site
100 km from Cognac in Nouvelle-Aquitaine Map produced on the OAlley site
Jean Castex, responsible for coordinating work on the release of containment, hinted on Wednesday that this distance "should be as the crow flies" adding in the aftermath that no decision had yet been made. The government's “Monsieur déconfinement” also opened the door to a possible relaxation: “We are going to refine a whole series of things, in particular the fact that in the same department we can continue to circulate if there are more than 100 km 'point to point'.