The human element in car following models.

This commentary distinguishes between the engineering-inspired formalisms used by Brackstone,M and McDonald,M (see ITRD E104802) and the psychological knowledge of, and assumptions about human behaviour when car following. It outlines a preliminary mathematical model, based on psychological knowledge about car following behaviour by human drivers, which could be applied in traffic engineering, as a means of bringing these two ways of studying car following closer together. (Author/publisher).