Transportation networks represent one of the key structural elements behind the functional properties of a large number of natural and man-made systems. In urban systems, they represent some of the arteries that regulate human mobility, especially in commuting scenarios. Moreover, they are by essence linked to the growth and development of urban areas, both in the exploitation of the urban space and its efficiency. Understanding the interplay between networks and urban exploitation represents a step forward in the study of cities and urban areas as complex systems, which in turn can be helpful for decision makers and urban planners. In this thesis focus on urban transportation networks by first approaching the problem by framing the system in the field as spatial networks, in particular we study subway systems as they exhibit complex spatial features and we expose their interplay with urban land use features.