Travel diary surveys of the past two decades typically contain substantial amounts of detail from which it is possible to build up a detailed picture of the travel behaviour of car users. Such a picture is of considerable interest to those examining the relative attractiveness of public and private modes. The mounting concern in many countries over road congestion, the intrusiveness of traffic, and air pollution has brought into question the extrapolation of historical car use patterns, even those constructed painstakingly from disaggregate, Revealed Preference (RP) data. It is arguable that new types of information are needed to interpret the impact of three important dimensions of the driving environment, all three of which are undergoing important changes at the present time: the traffic conditions; the automotive and highway technologies designed to alleviate traffic problems; and, evolving policies for the control of car-use. A problem for survey research is to incorporate information, not only about motorists' perceptions of the prevailing state of traffic, technology and controls, but also about the cumulative effect of all three on their willingness to own cars, and to use them more or less. This paper gives the preliminary results of an attempt to identify survey methods which would be more sensitive to these issues. It covers experimental work on survey instruments which attempt to measure how drivers' perceptions, both of actual trips during a diary period, and of the cumulative "stresses" of driving, relate to the set of travel opportunities they consider that they have available. The results of the experiments are expressed as a concept for an "ideal" methodological package for an in-depth interview in this area, and some general recommendations for car-use surveys.
Samenvatting