Millions of cars on road generate tons of data every day. Vehicle communication technology (including drivers' smart phones connected with 3G/4G/WiFi) provides us a new way of accessing this rich dataset.
University of Michigan Transportation Research Institute (UMTRI) hosts a connected vehicle research project called SafetyPilot originally intending to improve traffic safety by utilizing vehicle communication technology. Each participating connected vehicle has a message broadcasting equipment, as well as a GPS sensor. Some more advanced vehicles may equiped with message receiving device and/or even onboard warning system. Basic Safety Message is the essential information transmitted by these connected vehicles and some Road Side Equipment (RSE). BSM contains two parts of information. The first part is mandatory, including vehicle's GPS location, speed, acc/dec rates, paddel status, ligth status, heading direction and much more. The second part is optional environmental information, including for example weather condition, bus schedule etc. These BSMs are transmitted via Dedicated Short Range Communication (DSRC) at 10Hz frequence (That's really alot of data).
Evey 3-6 month, these vehicles will come back to UMTRI and upload their data. Since the commencement of the project in 2012, UMTRI is now hosting more than 70 billion BSM records on more than 4 million trips, all come from about 3000 connected vehicles (3~4% of the total car ownership).
Diving into this database, we are able to locate the data records we need in order to produce a road travel time estimation for the City of Ann Arobr. Due to the data availability, we present the visualized map for this city at 07:00 to 10:00 on Dec 2, 2013. Without doubt, same data processing method could be replicated to get road travel time estimation for any other time window, and even real time.
The tool we used to produce the map is ArcGIS 10.2. We produced a map for each 10 minutes. Each map, as a frame in the video, will be shown for 3 seconds. For your convenience, static maps (click for larger view) are also included at the end of the post.
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