ABSTRACT
This chapter discusses the collection of transport data and presents some general results based on the analysis of these data. Transport capacity is defined, and ways of measuring the vehicle and passenger capacities of public transport modes, roads and intersections are described. Transport performance is explained in terms of journey speeds, delays, travel times, 'generalised time' and 'generalised cost'. Systems modelling involves both the application of graph theory to the construction of abstract networks and the specification of mathematical functions to represent the interaction between traffic and transport. Public transport inventories include both identification of routes and the enumeration of the vehicles operating along those routes. Urban road capacity is often determined by the capacity of the critical points—the major intersections. For analytical purposes transport supply is represented as a network of nodes and links, with transport impedance associated with each link.
