Travel modeling has traditionally relied on survey data acquired through direct interaction with subjects. For years these proven methods have allowed for the collection of detailed trip and traveler information, serving as the basis for travel demand models. More recently, technological advancements and limitations associated with traditional travel survey data—including increasing cost and declining response rates—have resulted in the growing interest in and adoption of “passive” data collection techniques, which do not rely on traveler interaction. These technologies are enticing for their ability to generate massive quantities of travel data at a fraction of the cost of traditional methods.
The main objective of this project is to examine current passive data applications and identify key areas in need of further research with a particular focus on travel demand modeling. To achieve this, the study started with a literature review to identify recent research assessing the reliability and applications of mobile phone positioning, global positioning systems (GPS), Bluetooth®, social networking, and smart card data. Following the literature review, a web-based survey was developed and distributed to transportation professionals. The survey, and subsequent follow-up interviews, provided an understanding of the views and concerns of travel modeling practitioners regarding passive data.
Finally, a workshop was held with researchers and practitioners to present preliminary project findings and to discuss future research directions. Findings from the discussion and prior phases of the project were then used to develop recommendations for future passive data research. Although funding for passively collected data for use with travel demand models research will likely continue to originate from the state or regional levels in the near term, national funding opportunities are anticipated in the future as this field continues to mature.