This is the second report dealing with an idealised mathematical model whose object is to assist in formulating fundamental principles for the design of motorway networks. It is assumed that trips are generated with equal frequency at all points in an infinite plane, and that the destinations are equally likely to lie in any direction. All trips are of the same length when measured in a straight line. Travel is possible on a basic road system at a speed v at all points and in all directions. There is also a network of motorways on which vehicles travel at a greater speed V. The earlier report was concerned primarily with rectangular networks of motorways, and expressions for the average journey time for a journey were obtained for various special cases and for long and short trips. The present report gives a rather similar analysis for a motorway network which divides the area into hexagons. It is found that for all values of the various parameters which have been studied, the average journey times for hexagonal and square networks with the same lengths of motorway per unit area are very nearly the same, within a few per cent. The differences are in general much less than those between networks having rectangular cells of different proportions.
Abstract