Press Releases

I-95 Corridor Coalition Validates Quality of INRIX GPS-Enabled Traffic Probe Data in Comprehensive Study Across 4 States

KIRKLAND, WA. – February 17, 2009 – INRIX announced today that the I-95 Corridor Coalition has completed the most comprehensive validation of vehicle probe data ever in the U.S., finding that the quality of INRIX traffic information “provides an accurate overall picture of traffic conditions for limited access roadways within the corridor.” INRIX also published today its own report, Benchmarking Traffic Data Quality: Best Practices for Analyzing the Quality of Traffic Information. The guide is designed for automobile OEMs, transportation agencies, wireless carriers and developers of location-based services as a guide showcasing best practices, metrics and INRIX thought leadership on the important topic of traffic data quality.

The four month I-95 Corridor Coalition study analyzed traffic on 111 miles of highways across Delaware, Maryland, New Jersey and Virginia. Using innovative Bluetooth reader technology, the study compared 19,000 observations of ground-truth vehicle speeds for over 1,500 hours on 54 road segments against real-time speed information for those road segments that INRIX provides as part of its contract to the Coalition.

The University of Maryland, contracted by the I-95 Corridor Coalition to conduct the study, found that the INRIX travel time and speed data across the system and by individual states generally satisfied the accuracy specifications of the I-95 Coalition Vehicle Probe Project contract. Further review established that in over 85% of the ground-truth comparisons, INRIX traffic data was within 5 miles per hour of the ground truth speeds. The study concluded “this result confirms that the INRIX GPS data provides an accurate overall picture of traffic conditions for limited access roadways within the Corridor.”

“This validation work is an important first step in the analysis of the INRIX data, and we are pleased that the results indicate the speed and travel time data meet our requirements for accuracy,” said George Schoener, executive director of the I-95 Corridor Coalition. “Our member agencies are already making excellent use of these data in the operations and management of their traffic systems.”

INRIX is able to deliver the nation’s broadest and most accurate real-time traffic information via its distinctive crowd-sourced traffic information network and data fusion technologies. INRIX intelligently blends billions of real-time data points from nearly a million GPS-enabled commercial and consumer vehicles including taxis, service vehicles, airport shuttle services and long haul trucks as well as consumer cellular GPS-based devices and traditional road sensor information. This innovative approach uniquely enables INRIX to provide real-time flow coverage on over 120,000 miles of roads and 140 markets across North America and Europe.

“This I-95 Corridor Coalition study is another clear validation of INRIX’s unique approach to building the broadest and most accurate traffic data network on the market,” commented Rick Schuman, vice president of public sector at INRIX. “The Coalition should be applauded for conducting one of the most comprehensive evaluations of vehicle probe data ever completed. We intend to continue our extensive collaboration with the I-95 Coalition and its member agencies as they integrate data from the Vehicle Probe Project to maximize the project’s value.”

In a further industry effort to demystify the quality analysis of traffic information, INRIX also released today the new Benchmarking Traffic Data Quality guide. This technical primer on traffic data quality provides a benchmark from which to evaluate the many components that make up the quality of traffic information. The report describes the processes and methods INRIX uses to validate, measure and verify the quality of incoming traffic reporting data. In addition, it outlines best practices for the planning and execution of ground truth testing of traffic flow data, including the results of tests conducted by INRIX and its partner, Clear Channel Total Traffic Network. Benchmarking Traffic Data Quality includes the results and an executive summary of the I-95 Corridor Coalition quality validation and is immediately available at

“In evaluating traffic information providers, data quality is generally the most important criteria our customers consider since it has a direct and critical impact on the end user experience,” said Craig Chapman, chief technical officer at INRIX. “The challenge has been that quality is very difficult to measure and quantify. We are publishing this Benchmarking Traffic Data Quality guide to share the methods and results learned from our years of experience and to highlight INRIX’s dedication to continuous improvement of our quality data processes.”

About the I-95 Corridor Coalition Vehicle Probe Project
The I-95 Corridor Coalition is facilitating a groundbreaking Vehicle Probe Project (VPP) involving the public and private sectors as well as academia to collect and evaluate real-time travel time and speed data for over 3,700 centerline miles of freeways and arterials in New Jersey, Pennsylvania, Delaware, Maryland, Virginia and North Carolina. The VPP began with the release of a Request for Proposals in May 2007 followed by a contract award to INRIX, Inc. in January 2008.

INRIX data primarily comes from GPS equipped vehicles, and is supplemented by sensor- and detector-based data in some states. These data are facilitating traffic management, traveler information and planning activities for both local and long distance travelers. In July 2008, INRIX activated the data feed for the network. Data collection for the initial evaluation activities were conducted by the University of Maryland, on behalf of the I-95 Corridor Coalition, between July and October 2008. The 128-page report summarizes the methodology and results of the initial evaluation and discusses outstanding questions and issues on how to appropriately assess data quality and planned steps to move forward. The full report is available at

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