Towards City-Scale Smartphone Sensing of Potentially Unsafe Pedestrian Movements

This paper proposes large scale collection of pedestrian movement data to promote pedestrian safety in our rapidly developing urban environments. As a first step, we develop and test algorithms for sensing unsafe pedestrian movements. With distracted pedestrian fatalities on the rise, and larger than ever use of smart devices, we propose to use the smartphone to protect pedestrians by leveraging the in-built inertial sensors on the smartphone. We discuss how to use these sensors for recognizing user movements that could be potentially risky when walking on the street, while also accounting for different phone orientations. We introduce a simple path prediction technique and use this to compute potential street crossings. In order to evaluate our algorithms, we conducted walking trials and collected data from all relevant sensors. Initial tests indicate a 90.5% success rate in predicting that a pedestrians trajectory will cross a road.