Given the high market penetration of GPS-enabled cell phones, these units can be used as sensors to obtain an enormous amount of information with the potential to improve the availability of data needed to implement the Dynamic Traffic Assignment (DTA) algorithms and procedures used to maximize the network’s capacity utilization. Dynamic Origins-Destinations and Dynamic Mode Identification are two aspects of DTA that can benefit from the data gathered. The algorithms and procedures proposed in this paper consist of using GPS-enabled mobile phones as sensors (probes) to determine origins, destinations and modal components of trips without user input. The main algorithm is called the Mode Identification Algorithm (MIDA), designed to identify origins and destinations of the following modes: pedestrians, motorized vehicles and heavy rail. MIDA does not identify trips on buses and it was developed to identify heavy rail trips only on single route networks. MIDA is divided into two components, Identification of Heavy Rail (IDHR) under the limitation previously described and Identification of Stop, Walk and Motorized vehicles (IDSWAM). The IDHR component relies heavily on positioning, while the IDSWAM component is a fuzzy algorithm that relies on speed, direction and consistency. The algorithm was tested with data gathered on the field. MIDA was tested in its identification of several modes, and it showed to be capable of doing so. Testing MIDA with data from volunteers showed an error of less than 6% in the identification of modes over the time period of the tests.
Keywords—GPS Tracking, Mode Identification, Origin-Destination Matrices, and Fuzzy Logic
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