Identifying Unusual Pedestrian Movement Behaviour in Public Transport Infrastructures

1. Introduction The investigation of pedestrian spatio-temporal behaviour and related influence factors plays an important role in the field of mobility research. In several of our research projects, we are particularly focusing on pedestrian activities and motion tracks in medium-scale investigation areas (e.g. large infrastructures or urban quarters). As part of one recently completed study we investigated motion behaviour and activities of passengers under time pressure in a public transport infrastructure. The overall aim of the project was to identify stress-inducing factors in transport infrastructures and their effects on navigation behaviour of passengers as well as the passengers´ strategies of gathering information and coping with stress. We conducted experiments with participants of four different target groups (young and elderly people, both either experienced in using public transport or not) in a laboratory environment and during field tests, applying a combination of different complementary methods such as physiological measurements of heart rates, visual field analysis based on eye-tracking data, interviews, and semi-automated annotation of trajectories and activities for identifying potentially stress-influenced behaviour. Observing and analysing the spatio-temporal movement patterns of the test subjects was a main part of the field tests. Several potential indicators for stress-induced behaviour can be identified through observation. For our study, we specifically focused on motion-related indicators such as . unusual speed levels (high speed - hurrying, or very low speed - hesitating, indicating uncertainties), . frequent stops (e.g. for gathering information), or . uncertainties in route choice (e.g. changes in direction, turning back). To collect the required spatio-temporal data, we used the method of "shadowing" (Millonig et al. 2009). "Shadowing" is a form of tracking where researchers follow the test subjects and annotate the test subjects´ individual trajectories and related activities on a map. In the course of this study, this was done by applying specific software installed on a tablet PC, which allowed annotating the information in digital form. The use of technology in this phase (digital map on a tablet PC, tracking software) offers mainly two major advantages: firstly, a large investigation area can be covered without having to handle a large paper map, and secondly, all points drawn in the map are recorded with time-stamps and map coordinates, which allows calculating average speeds and detecting stops for each trajectory. Additionally, the system allows annotating specific activities carried out by the participants when they stop (e.g. gathering information from a public display). The participants had to find a particular destination by using predetermined modes of public transport. The trajectories have been collected in the connecting stations the participants used on their way. In total, 25 test persons participated in Vienna, 10 test persons have been tracked in Graz.