THE TRAFFIC CAPACITY OF MAJOR/MINOR PRIORITY JUNCTIONS

A study has been made of the traffic capacities of non-priority streams at major/minor priority junctions. Except at abnormally high major road flows the capacities depend linearly on the flow in the relevant priority streams of the major road. The relationships depend on the lane width available to the non-priority stream, the visibility T waiting drivers, the width of the major road, and, at dual-carriageway sites, on the width of central reserve. A framework of predictive equations has been developed. In addition to normal capacity prediction, methods have been developed to allow the equations to be used specifically (I) to take account of local operating conditions at overloaded existing sites, and (II) to predict the effects of changes to the geometry of existing sites.(a) (TRRL)