FORMING A COMPREHENSIVE TRANSPORTATION FLOWS MODEL

EFFORTS WERE MADE IN THE PENN-JERSEY TRANSPORTATION STUDY TO DESIGN A TRANSPORTATION FLOW SIMULATION MODEL THAT: (1) WOULD BE EXPRESSING THE AUTHORS' PHILOSOPHICAL APPROACH, AND (2) WOULD CONSIST OF TECHNIQUES THAT WOULD EXPLICITLY INDICATE RELATIONSHIPS TO BE INVESTIGATED AND CLARIFY THE ANALYTICAL PROCESS TO BE FOLLOWED IN EACH CASE. THE FIRST STEP IN THE TRANSPORTATION FLOW MODEL IS THE SIMULATION OF TOTAL TRIPS GENERATED WITHIN THE VARIOUS PARTS OF THE REGION. THE MULTIPLE REGRESSION TECHNIQUE USED IS THE ONE ESTABLISHED BY OTHER TRANSPORTATION STUDIES. THE OUTPUT OF THE TRIP GENERATION MODEL COMPONENTS WOULD BE: (1) THE TOTAL PERSON-TRIPS GENERATED BY EACH ACTIVITY AND IN TURN BY EACH SUBAREA OF THE REGION, WITHOUT REGARD TO TRAVEL MODE, (2) ACCESSIBILITY FACTORS SHOULD BE INCLUDED WHICH AFFECT THE TOTAL TRIP GENERATION PROPENSITIES OF AN ACTIVITY IN THE AREA, AND (3) SEPARATE GENERATION OF TRUCK TRIPS SHOULD BE EXPRESSED AS AN AGGREGATE OF TRUCK TRIPS GENERATED BY THE COMBINATION OF ALL ACTIVITIES LOCATED WITHIN EACH SUBAREA OF THE REGION. THE SECOND STEP OF THE TRANSPORTATION MODELS DEALS WITH THE MANNER IN WHICH MASS TRANSPORTATION TRIPS IN THE REGION CAN BE SIMULATED AND PROJECTED AT ANY GIVEN TIME IN THE FUTURE. THE AMOUNT OF TRAVEL IN ANY AREA BY PUBLIC AND PRIVATE MODES OF TRAVEL HAS BEEN CONSIDERED TO BE PRIMARILY DEPENDENT ON THE FOLLOWING VARIABLES: (1) AUTOMOBILE OWNERSHIP, (2) INTERSITY OF LAND USE, AND (3) RELATIVE TIME AND COST OF TRAVEL BY MASS TRANSPORTATION VS. THE AUTOMOBILE. THE THIRD STEP OF THE TRANSPORTATION FLOW MODEL IS TO DISTRIBUTE TRIP ENDS FOR AUTO PERSON TRIPS, MASS TRANSIT TRIPS, AND TRUCK TRIPS. THE FOURTH STEP INVOLVES ASSIGNMENT OF TRIPS ONTO NETWORKS, BOTH HIGHWAY AND TRANSIT. THUS THE MODEL INCLUDES AN ESTIMATION OF TRAVEL IN TERMS OF MILEAGE, TIME AND COSTS INCURRED ON EACH SYSTEM USED.