Mobile phones as traffic sensors with map matching and privacy considerations

In the recent years, it has become readily more accepted that smart mobile phones with GPS or A-GPS enabled device, or even Cell-ID enabled, among the commuters, can be used as traffic sensor, which complements other traditional sensors. This development is pursued in the efforts of reducing or avoiding traffic jams. Consequently, this paper attempts to find a novel way to map match 2D local map with actual GPS traces from mobile phones. From a number of experiments, it has been found that Virtual Detection Zone method can be used to obtain 100% map matching, as it ensures matching by comparing the GPS data to a set of pre-determined check points (circular VDZ, preferably with a radius of 50-185m). Furthermore, from this study, it is proposed to increase privacy, firstly by using OTP to doubly-lock the sensor´s data. Secondly, by ensuring that valid data is only delivered from a significant distance of the user´s private locations, and thirdly, by splitting the data to two parts before using OTP.