ABSTRACT
The ‘aggregate sequential’ transportation planning process involves the accumulation of a considerable amount of basic data. Characteristics of the present-day travel pattern in the area under consideration must be collected, the future distribution of land use and population derived, the adequacy or otherwise of existing transportation facilities determined and spare capacity estimated. The different surveys necessary to collect the basic data are time-consuming and expensive in both staff and money. Outside the external cordon changes in the land-use pattern are considered to be less significant, and therefore are examined in a less detailed manner. The traffic zones defined beyond the external cordon cover the whole country. For internal traffic within the study area the aim is to define zones small enough to give accuracy of movement, and to allow reliable trip generation rates to be established. Traffic movement will certainly be related to population.
