Bias in trip rates obtained from travel surveys conducted by telephone

Whilst the advantages of telephone surveys have recently been widely touted, there has been little systematic investigation into the sample bias inherent in the method. This paper examines the bias in trip rates which would be obtained from travel surveys conducted by telephone. The analysis is based on the construction of samples of telephone owning and non telephone owning households from the 1978/79 Melbourne home interview survey. The paper examines the demographic, socioeconomic and travel characteristics in each of these samples. It is shown that while the telephone owning households make more trips than non telephone owning households, the majority of this difference can be explained in terms of the different characteristics of households in each of these samples (a). Only the abstract of the paper is bound with the conference papers.