TOWARD OPTIMAL PLANNING OF A TWO-MODE URBAN TRANSPORTATION SYSTEMS: A LINEAR PROGRAMMING FORMULATION

THE PURPOSE OF THIS STUDY WAS TO DEVELOP AN ANALYTICAL METHODOLOGY OR MODEL FOR FINDING THE OPTIMAL COMBINATION OF TWO MODES IN PROVIDING TRANSPORTATION SERVICE. THE SPECIFIC CASE TREATED WAS THAT OF PROVIDING AUTOMOBILE TRANSPORT FACILITIES AND POSSIBLY SOME RAPID TRANSIT FACILITIES IN A RADIAL, DOWNTOWN-ORIENTED CORRIDOR. THE OBJECTIVE WAS TO FIND THAT COMBINATION OF FACILITIES WHICH MINIMIZED TRANSPORT COSTS- INCLUDING BOTH CAPITAL AND OPERATING COSTS OF TRANSIT AND AUTO TRANSPORT DURING THE DESIGN OR HORIZON YEAR. SINCE TRANSPORTATION IS A SERVICE TO ITS ENVIRONMENT, THE SERVICES PROVIDED WERE REQUIRED TO HAVE CERTAIN ATTRIBUTES. THE CAPACITY OF THE TWO MODES HAD TO BE CAPABLE OF ACCOMMODATING THE PEAK PERIOD FLOWS. FURTHERMORE, THE SYSTEM HAD TO BE DESIGNED SO THAT THE PEAK PERIOD AND NON- PEAK PERIOD INTERZONAL TRAVEL TIMES DID NOT EXCEED THEIR RESPECTIVE MAXIMUM ACCEPTABLE VALUES. BECAUSE A TWO-MODE SYSTEM WAS DEALT WITH, THE MODAL CHOICE BEHAVIOR OF TRAVELERS HAD TO BE INCORPORATED INTO THE MODEL. IN ORDER TO INSURE THE USEFULNESS OF THE MODEL, IT WAS DEVELOPED WITH REFERENCE TO A SPECIFIC REAL WORLD SITUATION IN THE CHICAGO AREA. THE NATURE OF THE COST FUNCTIONS FOR THE TWO MODES AND THE CONSTRAINTS RELATED TO CAPACITY, TRAVEL TIMES, AND MODAL CHOICE WAS SUCH THAT THE PROBLEM COULD BE CHARACTERIZED WITHIN THE FRAMEWORK OF LINEAR PROGRAMMING. THIS VERY EFFICIENT OPTIMIZATION TECHNIQUE WAS USED TO FIND THE SOLUTION, WHICH APPEARED TO BE QUITE REASONABLE. /AUTHOR/