Abstract

The form of cities has a great influence on their social, economic and environmental outcomes, and complement their size effects. While there is commensurate research on measuring urban forms, only few relate those measures to city size or consider the relationship between road networks and urbanised land. Nonetheless, transport is key to the urban actors and actually to the understanding of positive and negative agglomeration effects related to population size.
In this study, we analyse the shape of urban road networks for over 300 cities in Europe. We use a monocentric and radial perspective because it is palatable to urban economics and to an effective simplification. Our first data source serves to identify the location of people within urban areas. We combine the Urban Atlas land use maps (Copernicus, 2006) and the Geostat 1 km population grid (Eurostat, 2006). Our second data consists in computing fastest car routes from a sample of urbanised locations at different distance bands from the main center of each city, using the Google Maps algorithm. We examine the internal radial profiles of road distances, compare them to the Euclidean distances, and investigate how and why this relationship between those two distances vary across Europe and across city size.