The logsum is a measure of consumer surplus in the context of logit choice models. In spite of the abundant use of logit models in transport, project assessment is only rarely done using logsums. Instead in project evaluation or appraisal, changes in transport costs and time (borrowing values of time from some source) are commonly used to get the traveller benefits. This report contains a review of the theoretical and applied literature on the use of logsums as a measure of consumer surplus change in project appraisal and evaluation. It then goes on to describe a case study with the Dutch National Model System (LMS) for transport in which the logsum method and the commonly used value of time method are compared for a specific project (high speed trains that would connect the four main cities in the Randstad: Amsterdam, The Hague, Rotterdam and Utrecht).
Table of Contents
Introduction to the main concepts
Review of papers on the theory of the logsum as an evaluation measure
Review of papers on the application of the logsum as an evaluation measure
Outcomes from the LMS case study
Summary, conclusions and recommendations