SPATIAL-ASPECTS OF TRAFFIC CIRCULATION .1. A REVIEW OF ALTERNATIVE SYSTEMS

One of the key aims of traffic management is to encourage drivers to f ollow an efficient routing pattern (i.e. a set of routes that collecti vely minimise the potential for delays and accidents and possibly also minimise travel distance). At present, little is known about the rela tive merits of different patterns or how they Could be accommodated or encouraged within existing city centre networks. A number of archetyp es are compared using total vehicle conflicts and total travel distanc e as the main criteria. They include several that have not previously appeared in the literature, and, the conflicts are weighted to reflect variations in the severity of the interactions between vehicles carry ing out different turning movements at junctions. The results indicate wide variations in the characteristics of different routing patterns and suggest new ways of organising the spatial pattern of traffic circ ulation as possible alternatives to the conventional gyratory system.