CAR AVAILABILITY AND MODE CHOICE: A DISCUSSION PAPER

A number of urban transport studies have shown the overwhelming importance of household car availability as a variable in determining whether journeys are made by non-car modes, particularly bus. But few studies have attempted to explain the detailed choice processes involved and therefore the extent to which their results are accurate and can be influenced by policy. This lack of explanation and understanding has meant that the concept remains somewhat confusing both to professional transport planners and members of the public who are asked about it in surveys. This paper aims to discuss four main aspects of the car availability decision process: (I) the likely accuracy of survey data; (II) the allocation and/or transferability of household cars between the members of the households; (III) the characteristics of particular journeys which influence the significance of car availability in modal choice the influence of the car availability concept on car passenger travel. The paper also attempts to draw some general conclusions on the implication for further surveys and analysis using the car availability concept. Some new evidence is presented based on recent surveys (both qualitative and guantitative) carried out in South Yorkshire. (Author/TRRL)