Commercial Vehicle Global Positioning System Based Telematics Data Characteristics and Limitations

The use of the United States’ Global Positioning System (GPS) to assist with the management of large commercial fleets using telematics is becoming commonplace. Telematics generally refers to the use of wireless devices to transmit data in real time back to an organization. When tied to the GPS system telematics can be used to track fleet vehicle movements, and other parameters. GPS tracking can assist in developing more efficient and safe operations by refining and streamlining routing and operations. GPS based fleet telematics data is also useful for reducing unnecessary engine idle times and minimizing fuel consumption. Driver performance and policy adherence can be monitored, for example by transmitting data regarding seatbelt usage when there is vehicle movement. Despite the advantages for fleet management, there are limitations in the logged data for position and speed that may affect the utility of the system for analysis and reconstruction of traffic collisions. The U.S. Air Force is responsible for maintaining and operating the GPS space and control segments and publishes information about these limitations. The most significant of these limitations do not have serious effects on the use of this data for daily fleet operations, but may have effects and limitations for use in accident reconstruction. These limitations are specific to the accuracy of the position data, the reported vehicle speed, and changes in vehicle speed during acceleration maneuvers. User segment GPS telematics data generated during typical vehicle dynamic maneuvers of medium-duty commercial delivery vans was studied and their accuracy analyzed and discussed. Testing of various maneuvers was conducted at a western U.S. location and an eastern U.S. location. The telematics data validity and reliability was assessed by comparison to data gathered using the GPS based Racelogic VBOX III data acquisition system with a corrected signal, via a GPS Base Station, for baseline reference. The findings present the calculated accuracies for speed and position data.