Traffic Bunching

Whilst trying to cross the road in Hursley this morning, I was struck by how the cars arrived in a long bunch that prevented me from crossing. Someone pointed out that in this case it was probably caused by the traffic light at the end of the village. This got me to thinking: is it important to have cars bunched? If they had been evenly distributed along the road, is it possible that they would be just close enough never to give me a gap large enough to cross? However, it also seems obvious that too much bunching would cause further jams at intersections where bunches came together. Is there an optimum bunching level for any given section of road, and if you plotted it against the width/intended capacity of the road, is there a correlation?

Has anyone done research on this? I guess it might come under the larger umbrella of queueing theory.