A procedure for synthesizing travel movements in small and medium-sized urban areas begun in 1961-1963 by the planning staff of the north carolina department of transportation is described. Four methods are used, depending on the extent of travel surveys done as part of the transportation study. Method 1 uses data from an external-cordon, origin and destination (o-d) survey and small-sample, internal, o-d survey. Method 2 procedures are followed if only an external-cordon, o-d survey is done. Method 3 requires only travel data from aninternal o-d survey. Method 4 is followed if no o-d surveys are done. All four methods require comprehensive traffic volume counts and comprehensive inventories of employment, commercial vehicles, and dwelling units. The north carolina procedure has greatly reduced the time and cost required for the travel-modeling phase of transportation studies and has enabled more time and effort to be devoted to travel forecasting and transportation plan development and evaluation. Abrief history of the evolution of the synthesis procedure is included. This paper appeared in transportation research record no. 1139, Urban travel forecasting. For covering abstract see IRRD no 817822.
Abstract