Travel characteristics survey - Method of expanding household interview survey data

In 2002, the Transport Department conducted a large-scale Travel Characteristics Survey with a view to collecting the public's views and attitudes towards the transport system, and the necessary data for the recalibration and enhancement of the comprehensive transport model in Hong Kong for planning purposes. in the Survey, about 1.4% of the population or 30,000 households were successfully interviewed. Information on the socio-economic data of the selected households and a 24-hour trip log for each household member were collected. Like most interview surveys requiring respondents to provide very detailed trip information for a full reference day, under-reporting of trips inevitably occurred in this Survey. Very serious underestimation of trips would result if the data was simply expanded according to the sampling factors. This paper presents the method adopted for expanding the survey data to match with independent data with a view to addressing the under-reporting problem and obtaining the overall territorial trip pattern for further use.