The Utility of Travelling When Destinations Are Heterogeneous: How Much Better Is the next Destination as One Travels Further? 2002

In many studies travel behaviour (for example, commuting) is analysed on the basis of a utility function with the distance travelled (d) as one of the arguments. An example is U=U(d,Y-cd,T-td), This standard approach is not without problems, however, since it ignores the fundamental fact that most transport has a derived character: travelling kilometres is not an activity that gives utility per se, but only because these kilometres bring people to certain places they want to visit. In this paper we develop a method that provides a justification for utility functions such as shown here by showing that these can be made consistent with theories that take into account the derived character of transport. The core element of our approach is that individuals compare potential destinations of their trips that are heterogeneous in terms of distance travelled and quality offered. Given the spatial distribution of destinations and the distribution of the quality of the jobs, one can derive the set of non-dominated alternatives that may serve as a destination. This nondominated set is essentially a monotone relationship between distance travelled and utility of the trip. Examples of this curve are given under various assumptions concerning the spatial density of destinations and urban form. Implications of this approach are discussed for commuting distances of different types of jobs. Our approach gives an explanation for the paradox that highly educated workers tend to have long commuting distances. Given their high value of time one would expect short commuting distances, but the low spatial density of their jobs appears to dominate the outcome.