Looking Beyond Commuter Travel in Cape Town: Methodological Lessons from the Application of an Activity-Based Travel Survey

Abstract

The way the passenger transport problem has, in the past, been framed in Cape Town and other South African cities, and the nature of the transport modelling exercises that have given rise to large-scale surveys, have resulted in a limited understanding of travel behaviour beyond home-based work tripmaking and morning peak period traffic volumes. Within a new South African transport policy environment however -where the discourse has shifted from 'commuter-based' to 'customer-based' service provision, and from supply-side to demand-side strategies -current understandings of travel needs and behaviour are insufficient. Little is understood of household constraints on travel decisions, of non-work, informal work, off-peak and non-motorised travel needs, as well as of so-called 'equity gaps' in transport supply. Richer, better quality data are required to implement and monitor the new transport policy, and innovative methods will be required to collect and analyse these data.This paper reports on the experiences of a survey aimed at collecting rich data through methods that are, to a large extent, innovative in the South African context. This survey, in the form of an activitybased household travel survey, was conducted in late 2000 and early 2001. The choice of, and some theoretical background to, the survey methodology is discussed. A description of the survey instrument, sample selection, survey administration and data capture and analysis is provided. Methodological lessons from the design and administration of the survey are identified. These centre around the importance of interviewers in successful surveying, interviewer versus self-completion of activity diaries, the impact of computer-assisted interviewing technology on substitution rates, recall periods, and trip recall.

Introducing multitasking to the study of travel and ICT: Examining its extent and assessing its potential importance

“…The pursuit of representativeness in the sample was not considered the most appropriate way in which to make theoretical and analytical advances in relation to this research (Behrens, 2003;Mason, 1996). Rather, the study aimed to gain a sample representing the four factors deemed key to the research area.…”

Collection of passenger travel data in Sub-Saharan African cities: Towards improving survey instruments and procedures

“…The table indicates this methodological variety in terms of the nature of the sampling unit, the site at which the survey takes place, the time period for which travel data is collected, the data collection procedure followed, the type of survey instrument used, and the types of questions asked in questionnaires. Arentze et al, 2004;Behrens, 2003;van Zyl et al, 2001). …”

“…As a result, such respondents typically provide hurried and unreliable answers or refuse outright to participate in the survey. In the case of self-completed diaries in Cape Town some respondents who initially agreed to participate in the survey, subsequently failed to complete their diaries once the effort that was entailed became clear (Behrens, 2003). In West African surveys, especially in the largest households, even if the head of household agrees that his or her household be surveyed some members refuse to participate.…”

“…In the case of a self-completed activity diary pilot test in Cape Town, Behrens (2003) cites the example of a respondent recording in the table that the first activity of his 10 24 hour day was sleeping, and that this was done by minibus-taxi two to three times a week. Further common errors associated with an inability to complete tables were a lack of symmetry between forward and return trips recorded in diaries (e.g.…”

“…An often cited problem in self-completed questionnaires is an inability of respondents (and in some instances by supervisors and interviewers as well) to read and complete diary tables as a series of intersecting columns and rows (Behrens, 2003;van der Reis, 1997). Less educated respondents are not always familiar with the concept of filling answers in designated spaces, which often results in the intended answer to one question being filled in the space intended for the answer to another.…”