Proxy Responses in Self-Completion Travel Diary Surveys

Abstract

This paper examines the characteristics of proxy respondents and those completing survey forms for proxy respondents in self-completed questionnaire travel diary surveys. With data from the Coastal South-East Queensland (Australia) Travel Survey, in which a special question was included about who completed the travel diary, it was found that about 30% of respondents were proxy respondents. The young were more likely to be proxy respondents, and males of all ages were more likely to be proxy respondents than females of the same age. Females were most likely to be the ones completing the travel diary for people younger than 35 years, whereas persons of the opposite sex were most likely to complete the forms for proxy respondents older than 35 years. Proxy respondents were more likely not to make any trips on the travel day; those who did travel had fewer stops and less travel time and travel distance than those who self-reported their travel. However, one has to be careful in interpreting these results because of the confounding effects of the demographics of proxy respondents versus self-reported respondents. In particular, it is known that younger people, who have fewer stops and less travel time and distance, are much more likely to be proxy respondents. Therefore, the stops, travel time, and travel distance for proxy respondents will automatically be lower than for self-reported respondents even if there were no effect of proxy reporting on reported daily travel.