Cognitive organization of roadway scenes : an empirical study.

This report describes six studies investigating the cognitive organization of roadway scenes. These scenes were represented by still photographs taken on a number of roads outside of built-up areas. Seventy-eight drivers, stratified by age and sex to simulate the Dutch driving population, participated. In the first study, subjects were asked to sort the photographs presented to them into piles of similar photographs. These piles were intended to be `meaningful' and `useful' to the subjects. In the second study, the same subjects were again asked to sort the same photographs into new piles on the basis of two other criteria. In other studies, other subjects: (1) sorted homogenous subsets of the same photographs; (2) named differences in pairs of widely different photographs; (3) estimated a safe driving speed and the chance of encountering `slow' traffic for the photographs presented; and (4) learned to classify each photograph in a pre-determined category. The report shows that three factors on average are of great importance, when subjects in their roles as drivers view a road scene. These factors are: (a) the presence of an intersection; (b) the number and breadth of carriageways; and (c) the presence of a curve