Institute of Transport Studies, University of Leeds
Abstract
This paper reports the findings of further work undertaken on the
Stated Preference (SP) data collected as part of the Department of
Transport's Value of Time Project. The latter study estimated values
of time in a variety of different circumstances and for a number of
modes of travel and also examined how the value of time varied
according to socio-economic factors. Although values of time were
allowed to vary across individuals by segmenting the data according
to socio-economic factors, the SP data permits the estimation of
values of time at the individual level whereupon a distribution of
individual values can be obtained.
The Department of Transport expressed some interest in what
information could be provided by the SP data about the distribution
of values of in-vehicle time across individuals. Individual values of
in-vehicle time have been estimated for each of the five SP
experiments which had previously been conducted to obtain a
distribution for each survey context and also pooled across surveys
to derive a population distribution. The problems of estimating
values at the individual level with the SP data available are
considered and the findings are compared with the average values
previously derived in the Value of Time Study. How these individual
values of time vary with socio-economic factors is also considered
