This research explores the relocation of supermarkets in medium-sized town centres from a carbon emissions perspective. 

Why this research? 
This research project is based on two observations. The first is of a socio-economic nature, since it concerns the commercial devitalization of medium-sized town centres to the benefit of suburban commercial centres. This "crisis" of centrality is a national issue, highlighted in particular by the "Action Cœur de Ville" plan, which emphasises the scarcity of town centre shops, thus disrupting the social role that trade plays in urban structuring. The second observation stems directly from the first: the mobility resulting from this commercial model causes a continuous increase in the number of journeys by private vehicle by consumers living in town centres to large stores on the outskirts and significantly worsens the carbon footprint induced by the daily consumption of households in medium-sized towns. This phenomenon contradicts the national objectives of carbon neutrality by 2050 and the reduction of the carbon footprint of French consumption set out in the Energy Transition Law for Green Growth of 17 August 2015. The construction of these peripheral commercial centres is also an important factor in urban sprawl, the artificialisation of land and the loss of quality of urban space.

Methodology and results
Faced with these socio-economic, environmental and architectural challenges, we can assume, as a scientific hypothesis, that there is an urban solution that satisfies the constraints imposed by public policies, the evolution of consumer demand and the current strategies of the actors of the commercial offer. Our research explores this theoretical solution through simple mathematical modelling which we can then adapt to urban and economic realities. We have developed a tool to calculate the carbon emissions of individual transport for commercial purposes according to a relocation index. For the moment, we have applied our research to the city of Bourges.