PANEL DISCUSSION ON INTER-AREA TRAVEL FORMULAS

THIS PANEL WAS DEVOTED TO THE PREDICTION OF TRAVEL PATTERNS AT SOME TIME IN THE FUTURE. IN ALL, SIX METHODS WERE DISCUSSED (1) THE GROWTH FACTOR, INCLUDING THE FRATAR FORMULA, WHICH PROJECTS THE PRESENT TRAVEL PATTERN FORWARD ON THE BASIS OF ANTICIPATED GROWTH IN DIFFERENT AREAS, (2) THE GRAVITY MODEL, WHICH ASSUMES THAT THE TRAVEL BETWEEN TWO AREAS DEPENDS ON THEIR ATTRACTIVE POWER AND THE DISTANCE BETWEEN THEM, SIMILAR TO THE LAW OF GRAVITATION, (3) AN ELECTROSTATIC FIELD THEROY, (4) INTERVENING OPPORTUNITIES, WHICH ASSUMES THAT TRAVEL WILL TAKE PLACE IN SUCH A MANNER TO MINIMIZE TIME, (5) MUTIPLE REGRESSION, AND (6) COST OF TRAVEL.