This paper presents a new technique of time allocation in transport modelling, when amounts of time and money for travel are limited. It transforms the theory of flexible budgets into a mathematical formulation of transport planning models. It uses a utility maximisation approach, where the utility of performing an activity depends on its type, duration, and location in terms of travel distance. In the first stage of the model, the population is classified into several groups, at an individual level, based on their lifestyle and social characteristics. Then car ownership is calculated for each group, using a standard model such as a binomial logit model. On a short-term level, the allocation of time and money to travel and other discretionary activities is calculated. This leads to the calculation of the total distance travelled per mode, and to the time and money expenditures on travel, in relation to the total expenditures on activities. Specific attention is paid to dynamic aspects of the system, including feedback loops and time delays. Some recommendations are made for further research.
Abstract