Present modelling technology is to a large extent con- strained by the characteristics of existing data systems. Some of the problems posed by the lack of an adequate, longitudinal data set describing the locational preferences, daily activity sets and daily travel patterns of urban households are examined, and the use of a permanent response panel-analogous to the consumer panels employed in market research- as a means of collecting such information is proposed. Consideration is given to the need for both long- and short-run data, with particular reference to /1/ model structure and calibration, /2/ forecasting and /3/ before- and-after studies. A brief description is given of a case study, employing the panel technique, in which data on daily travel behaviour were collected for a sample of 50 house- holds for a period of one month. Finally, a scheme is proposed for the continuous monitoring of urban travel demand, integrated within the framework of a continuing urban transportation study. /author/.
Abstract