Kay Kitazawa

Gender differences in children's pathways to independent mobility

This paper presents some empirical findings relating to the independent mobility of children in two parts of south-east England – one a south London borough, the other a suburban county north of London. In both locations boys appear to enjoy greater mobility than girls, and become independent much earlier. But closer analysis suggests that girls manage to attain similar levels of independence from adults by travelling more in groups. This collective independence achieved through peers is often overlooked, and may compensate modern children to some extent for their loss of individual freedom.

Pedestrian Vision and Collision Avoidance Behavior: Investigation of the Information Process Space of Pedestrians Using an Eye Tracker

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. Particular foci of our study were on identifying the size and shape of IPS through examining observed gaze patterns of pedestrians. A series of experiments were 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 25 Hz. Our findings are three folds: pedestrians pay much more attention to ground surface to detect potential immediate environmental hazards than fixating on obstacles; most their fixations fall within a cone-shape area rather than semicircle; the attention paid to approaching pedestrians is not as high as that to static obstacles. These results led to an insight that the structure of IPS should be re-examined by taking directional characteristics of pedestrians’ vision.

Using Laser Scanner Data to Calibrate Certain Aspects of Microscopic Pedestrian Motion Models

In this paper an automatic procedure to obtain trajectory data sets for controlled walking experiments based on laser scanner measurements is investigated. The laser range scanners provide raw data consisting of snapshots of scattered points with a frequency of 10 Hertz. A tracking algorithm is applied in order to convert the laser scanner measurements into trajectory data sets. Suitability of the method is demonstrated via the application to walking experiments performed in the London based walking laboratory PAMELA. Beside evaluating the accuracy of the obtained trajectory data the experiments are also used in order to enable data driven modelling of stopping and turning movements within the social force model paradigm. It is shown that via the modelling of a ‘desired velocity’ term inside the models the observed behavior can be modelled with reasonable accuracy.