Hybrid Traffic Data Collection: Integrating Probe Data with PeMS

Counting the actual volume of traffic at a location and determining its speed has long been the province of loop detectors buried in the pavement. However, the advent of GPS-equipped smartphones has given rise to the hope that “probe” data could one day supplement loop data to produce much more plentiful information. While this hope is becoming a reality, integrating probe data with traditional data sources accurately is no simple task. In this project, PATH investigated how Caltrans might go about buying traffic probe data from vendors, how to modify and manage it to make it useful, and how to integrate it with data from loop detectors archived into Caltrans’ existing performance measurement system called PeMS.