“Passively collected data” are gathered from non-traditional vehicle stream sources such as smart phones, vehicle transponders, and vehicle tracking devices, rather than with traditional roadway sensors. This study developed a guide to help public agencies purchase and test traffic volume information that is based on non-traditional data sources.
Recent research has shown that passively collected data hold promise for calculating important traffic volume information such as annual average daily traffic (AADT). To further evaluate the technical and statistical validity of AADT statistics derived from passively collected data, the Federal Highway Administration sponsored a pooled fund project. The study compared the precision and accuracy of AADT data derived from various passive data methods with AADT results derived from traditional continuous counts, factoring methods based on 48-hour counts, and other methods that state highway agencies use.
As part of that study, and as a subcontractor to Streetlight Data, Inc., TRAC researchers developed a guide for use by federal, state, and local highway agencies that contains a comprehensive technical checklist and data quality acceptance criteria. The guide will help agencies purchase or acceptance test traffic volume estimates such as AADT supplied by the private sector when those estimates are based on non-traditional data sources.
Specifically, the guidance is designed to help agencies prepare for purchasing data, interact with potential data providers, determine the quality and accuracy of the data, and evaluate their value. Four checklists are provided. The first helps agencies clarify their requirements before requesting bids. The second ensures that those bids include the data required to compare different offers. The third helps them judge the quality of the data and select among offers. The fourth helps them understand the technical procedures of the vendor providing AADT estimates.
Passive data collection methods, if validated, could reduce costs and improve the efficiency of collecting traffic data for state departments of transportation and other public agencies. They could also reduce risks to employees and contractors who place sensor devices on roadways by dramatically reducing the number of necessary field-based traffic counts.
Authors:
Mark E. Hallenbeck, Washington State Transportation Center-UW
Laura Schewel, Streetlight Data, Inc.
Sean Co, Streetlight Data, Inc.
Sponsors:
Streetlight Data, Inc.
FHWA