Entropy Model and Intercity Modal Split in the UK

Using the entropy trip distribution model of Wilson as a base, two intercity bimodal split models are developed; one with a negative exponential impedance function, the other with a negative power function. The models are calibrated and compared against rail and air domestic intercity travel data in the United Kingdom. The power function is found to give the best fit to the data. The most satisfactory model is used to predict modal share for changes in intercity travel times which have taken place and the predicted values compared with actual measured results. Additional outputs from the analysis are values of time for work and nonwork trips and the relative weighting of excess time to line-haul time as perceived by the traveler.