1. Analysis of trajectories of pedestrians in urban environments Monika Sester, Rodrigo Silveira, Jack Snoeyink, Stefan van der Spek, Bettina Speckmann, Robert Weibel

2. Outline General considerations (Preliminary) Experimental data – Field trip, data collection and analysis

3. General goal Use trajectory data, together with context information, to identify and study activities of pedestrians in city environments Input: trajectories + context

4. It’s all about context Where people walk, stop, shop Activities occur in features of interest in the city – Possibly at different levels of interest City/neighborhood/street/shop/information sign/etc Geographical context/constraints: map information (street network) – Depending on the scale, streets can become areas, points of interest can become areas of interest And many other exploratory variables… – Size/Opening hours of shops – Weather conditions – Demographic data (age, gender, motion capacity, etc.)

5. Algorithmic questions Distinguish between movement and pauses – Non-geometric feature, natural segmentation events Identify noise due to poor reception (e.g. indoors) – Better estimation of trajectory lengths Context information must be used – Important: map matching

6. Groups of trajectories Track groups of people More sources of information on behavior – +1 trajectories describing more or less the same But: Interaction between people influences trajectories – Particular patterns: wait for others, stop for discussion, leading, etc. Main question: What else can you say if you have group trajectories? – “Behavior of a group with multiple GPS devices”

7. Further considerations Data may include gaps – How can we fill them in? Next… analyze the actual data