Passive Origin-Destination Studies and Research

An origin-destination (O-D) study is used to identify travel patterns and movements of traffic during specified time periods such as an average weekday, weekend, or during major events. O-D data provide critical information for routing and alignment studies and in long-range transportation planning, especially in areas facing substantial growth.

MAG 2018 External Travel Study

Screenshot of an 'External-to-External Trip Flow Band Diagram' as displayed on the MAG External Travel Study website. In 2018 the Travel Survey and Passive Data research team assisted the Maricopa Association of Governments (MAG) with developing external travel data of cars and trucks for the region. This study was MAG’s first use of use passive GPS and Location Based Services (LBS) data for external travel estimation. The use of passive data for external studies is state-of-the-practice and provides significant benefits over prior methods such as roadside interviews and license plate matching techniques that garner safety and privacy concerns. The study’s primary objective was the development of traffic matrices of external O-D interactions for the regional travel demand model. The results of this study benefit many uses of the travel model such as evaluation of freeway improvements, new location corridors and tolling studies, as well as air quality/conformity assessments. Researchers used data management techniques, algorithms, and analytical computations to address the technical and data processing challenges inherent in using large amounts of passive data.

As part of this study researchers developed a custom algorithm of to estimate truck trips from American Transportation Research Institute (ATRI) truck GPS data and developed a custom MAG External Travel Study web site.

Synopsis of New Methods and Technologies to Collect Origin-Destination (O-D) Data

Cover of TMIP's 'Synopsis of New Methods and Technologies to Collect Origin-Destination (O-D) Data' report. TTI prepared the Synopsis of New Methods and Technologies to Collect Origin-Destination (O-D) Data report for FHWA’s Travel Model Improvement Program (TMIP) in 2016. The report provides an overview and detail on the use of cellular, GPS, and Bluetooth technologies for origin-destination (O-D) data. It discusses what each technology represents and its capabilities and limitations in relation to accuracy, sample saturation, and frequency. It includes takeaways and lessons learned from numerous studies in recent years that have used cell, GPS, and/or Bluetooth to collect O-D data. The report provides a comparison between the technologies in relation to the ability to provide O-D data by external trip types, by non-commercial and commercial vehicle categories, and by supplemental attributes such as residency status and routing. It discusses the suitability of each technology for planning versus operational O-D studies and for different geographic scales such as urban, regional, or statewide. The report provides potential users of O-D data sourced from cell, GPS, or Bluetooth general guidance on which technology or combinations of technologies is best suited for different O-D study types, sizes, and objective.

Optimizing Technology for Collecting Long-Distance Travel Data

Diagram from the Arizona DOT report showing the implementation framework for long-distance O-D data for the Arizona Travel Demand Model.
Implementation Framework for Long-Distance O-D Data for the AZTDM.

In the 2019 study, Optimizing Technology for Collecting Long-Distance Travel Data, TTI researchers developed an implementation plan and recommendations for developing long-distance travel data, defined as trips 50 miles or longer, for the Arizona Department of Transportation (ADOT) statewide travel demand model. Researchers evaluated origin-destination (O-D) data from cellular, global positioning system (GPS), Location Based Services (LBS), and Bluetooth technologies and compared their strengths and weaknesses considering sample penetration, accuracy, and the ability to estimate long-distance travel for different trip types and categories. Collage of Arizona-related logos, maps, and locations. The researchers found that ADOT should use LBS data as the primary source for passenger travel due to the relatively high penetration rate, better location accuracy than cellular data, and ability to estimate flows at a large geographic scale. They found that ADOT should use GPS O-D data for truck travel, since commercial truck fleets have a significant sample penetration in GPS data. The study concluded that ADOT should acquire trip matrices for zone-to-zone truck flows or acquire trip records with waypoints for detailed study of truck flows on the highway network. AS part of the study, researchers provide a detailed implementation plan for integrating “new technology” O-D data into ADOT’s statewide model. The plan outlines important preparatory activities, tasks, and decisions that ADOT must address prior to acquiring data such as forming a technical advisory committee to help assess technical decisions, revising Traffic Analysis Zones to optimize passive data capture, and assessing the numerous forms and attributes available with LBS and GPS zones (data prior to acquisition).

For More Information

Ed Hard
(979) 317-2592
[email protected]


Byron Chigoy
(828) 675-5304
[email protected]