This study investigates the Information Process Space (IPS) of
pedestrians, which has been widely used in microscopic pedestrian
movement simulation models. IPS is a conceptual framework to define the
spatial extent within which all objects are considered as potential obstacles
for each pedestrian when computing where to move next. The particular
focus of our study was identifying the size and shape of IPS by examining
observed gaze patterns of pedestrians. A series of experiments was conducted
in a controlled laboratory environment, in which up to 4 participants walked
on a platform at their natural speed. Their gaze patterns were recorded by a
head-mounted eye tracker and walking paths by laser-range-scanner–based
tracking systems at the frequency of 25Hz. Our findings are threefold:
pedestrians pay much more attention to ground surfaces to detect immediate
potential environmental hazards than fixating on obstacles; most of their
fixations fall within a cone-shape area rather than a semicircle; and the
attention paid to approaching pedestrians is not as high as that paid to static
obstacles. These results led to an insight that the structure of IPS should be
re-examined by researching directional characteristics of pedestrians’ vision
