PREDICTING FUTURE DEMAND FOR URBAN AREA TRANSPORTATION

A SUMMARY IS GIVEN OF THE RESULTS OF A STUDY OF CURRENT PRINCIPLES AND TECHNIQUES FOR PREDICTING THE PRESENT AND FUTURE DEMAND FOR URBAN AREA TRANSPORTATION, OFTEN REFERRED TO AS TRAFFIC ESTIMATION AND ASSIGNMENT. EMPHASIS IS PLACED ON THE TRANSPORTATION PLANNING PROCESS AS A TOTAL PROCESS, REQUIRING THE INTEGRATION OF MANY OF THE INTERACTING CHARACTERISTICS OF THE URBAN ENVIRONMENT. THE PRINCIPAL PHASES OF THE TOTAL PROCESS OUTLINED ARE: (1) INVENTORIES OF EXISTING CONDITIONS, SUCH AS LAND USE, POPULATION, VEHICLE OWNERSHIP, VEHICULAR AND PERSONAL TRAVEL, TRANSPORTATION FACILITIES, AND MONETARY RESOURCES, (2) ESTIMATES OF FUTURE URBAN AREA GROWTH IN TERMS OF POPULATION, ECONOMIC ACTIVITY, VEHICLE OWNERSHIP, LAND USE, AND AVAILABLE TRANSPORTATION NETWORK, AND (3) DETERMINATION OF FUTURE TRAVEL DEMAND BASED ON TRIP GENERATION, MODAL SPLIT, INTERZONAL TRANSFERS, AND THE ASSIGNMENT OF TRAFFIC TO TRANSPORTATION FACILITIES. THE FEEDBACK FROM LEVEL OF SERVICE SUPPLIED BY AVAILABLE FACILITIES TO TRAFFIC DEMAND IS STRESSED. FEATURES OF THE TRANSPORTATION PLANNING PROCESS WHERE CURRENT METHODS APPEAR INADEQUATE ARE POINTED OUT AND RECOMMENDATIONS ARE SUGGESTED FOR FUTURE RESEARCH. AN ANNOTATED BIBLIOGRAPHY INCLUDES 177 ITEMS PERTAINING TO LITERATURE ON PREDICTING THE FUTURE DEMAND FOR URBAN AREA TRANSPORTATION. /AUTHOR/