On the Numerical Measurement of Accessibility

Abstract

The aim of this paper is to clarify the validity of a fairly broad range of numerical indicators of accessibility. To this purpose a measurement-theoretic framework is presented, where accessibility is considered as a property of configurations of opportunities for spatial interaction. Within this framework a few established indicators of accessibility are discussed and notions of separable, additive, and maxitive indicators are introduced. An analysis is given of the validity of numerical indicators in general and of separable, additive, and maxitive indicators in particular.