A design tool to identify those elements of a road network necessary to support an efficient traffic routeing pattern

In an urban road network, with its relative density of junctions, it is the competition for road space at junctions that is a major contributor to both delay and the potential for accidents. One method of reducing that competition would be to allocate a route to each driver which involves minimum conflict with the other streams of traffic using each junction. It is shown that repeated application of this principle to each driver in turn results in a relatively efficient routeing pattern. A suite of computer programs, for use on a microcomputer, has been developed as a design tool to find such a routeing pattern for a given road network and trip matrix. With this design tool a traffic engineer could explore the potential for allocating trips more efficiently. The engineer would be interested in those links most used by such an efficient allocation. Some links will only be used in one direction; these would be suitable candidates for one-way operation. Reduction in conflict at junctions will sometimes be achieved by the complete avoidance of certain turning movements; these turns could be banned. Some properties of routeing patterns found for one real and one idealised network are described in the paper.