  The study of the properties and structure of a city's road network has for
many years been the focus of much work, as has the mathematical modelling of
the location of its retail activity and of the emergence of clustering in
retail centres. Despite these two phenomena strongly depending on one another
and their fundamental importance in understanding cities, little work has been
done in order to compare their evolution and their local and global properties.
The contribution of this paper aims to highlight the strong relationship that
retail dynamics have with the hierarchical structure of the underlying road
network. We achieve this by comparing the results of the entropy maximising
retail model with a percolation analysis of the road network in the city of
London. We interpret the great agreement in the hierarchical spatial
organisation outlined by these two approaches as new evidence of the
interdependence of these two crucial dimensions of a city's life.
