A PROCEDURE FOR ESTIMATION OF TRIP LENGTH FREQUENCY DISTRIBUTIONS

Data from 20 transportation studies were utilized to develop a procedure for the theoretical estimation of the trip length frequency distribution (TLFD) for urban areas, which would be useful in synthetic transportation study and the future projection of TFLD's. The procedure requires 2 data inputs; an estimate of the mean trip length and the maximum possible separation as defined by the network of the area being considered. A TLFD is then computed which is of approximately the same trip length as the value input to the procedure. Statistical tests were conducted to determine the accuracy with regard to the theoretical representation of the observed TLFD's. The procedure was analyzed for the estimation of home based work and nonwork TLFD's, and is also applicable to the estimation of nonhome based and truck-taxi trips. The procedure (which was demonstrated to be reliable by tests concerning its sensitivity with regard to the calibration process, variation in parameter values and variations in the input values to the procedure), may be used in lieu of an O-D survey to provide a reliable estimate of the TLFD for an urban area.