The Impact of Fast Routes on Urban Travel Geometry

Abstract

We examine some spatial properties of cities and obtain new results about how travel patterns are influenced by strategic routes such as radials and orbitals. Following a general introduction in which the basic approach is described, we develop a number of key principles, which build on our earlier work on velocity fields. Three theoretical case studies are described in which the authors show the expected patterns of quickest paths, isochrones, and catchment areas arising from alternative simple basic routing assumptions. We then elaborate the concepts of the hub, rim, and core of a city, showing how these features can be constructed and how they affect the pattern of travel. The results provide a number of insights that are then applied in a fourth case study to examine the effects of the M25 orbital on travel in London. Some policy implications are then explored before concluding with a discussion of potential applications and research.