Structural analysis and traffic flow in the transport networks of Madrid

As the framework to characterize the subway and urban bus networks of Madrid city three topological spaces: geographical stop space, transfer space and route space, are considered. We show that the subway network exhibits better structural parameters than the urban bus network, with higher performance since in average a stop is reachable passing through less number of stops and carrying out less number of transfers between lines. We have found that the cumulative degree distributions of the subway and urban bus networks correspond to an exponential function, while the degree-degree correlations present a power law distributions in both transport systems. The relationship between transport flows and population are also studied at the city level by analyzing the flow between all the district (administrative areas) of Madrid. We prove that these flows can be described by a Gravity Model which takes into account the population from the origin and destination districts as well as the number of sections of a transport line that passes through two different districts.