Over the last decade, a growing number of state departments of transportation (DOTs) have started to apply vehicle probe and cellular GPS data for a variety of uses. In recent years, the data has been put into mainstream use, propelled in part by the National Performance Management Research Data Set (NPMRDS), which consists of speed data from vehicle and cellular GPS probes, provided free to state DOTS. DOT use of GPS data includes real-time traffic and incident monitoring and communication, travel demand management, and to inform system planning and investment decisions.
GPS location data is derived from probes in fleet vehicles, in-vehicle navigation systems, connected vehicles, and cellphones and serves as a source of vehicle speed and volume data. NPMRDS consists of historical speed data from these sources, at the link level, for 5-minute intervals. It is provided to state DOTs as a source of travel time data for reliability, emissions, and congestion indicators they are required to report by MAP-21. In addition, several for-profit companies provide speed and relative volume data to state DOTs, including real-time data based on GPS locations from vehicle and cellphone probes. There are also tools that have been developed for the analysis of this type of data.
The objective of this synthesis is to document the state of practice regarding how state DOTs are applying vehicle probe and cellular GPS data for monitoring, planning, and real-time information. The study will also address data protection and privacy implications and whether these considerations are hindering states or entities from seeking GPS sourced data.
Information will be gathered through literature review, a survey of DOTs, and interviews with selected agencies for the development of case examples. Knowledge gaps and suggestions for research to address those gaps will be identified.
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