SMATS Volume Estimation Accuracy Evaluation in the MAG Region

Maricopa Association of Governments (MAG), the federally designated MPO for the greater Phoenix region, manages transportation planning across a network exceeding 10,000 square miles. When it came to evaluating whether probe-based volume estimation could reliably support regionwide data collection, MAG ran a rigorous validation across 300+ freeway, arterial, and intersection locations, spanning multiple road classes, area types, and time periods.

Traffic volume data is foundational to how planning agencies operate. It supports federal reporting requirements, informs competitive grant applications, and drives long-range planning decisions. For agencies managing large and growing networks, the question of whether probe data can meet that standard, reliably and at scale, is one with real consequences.

SMATS developed a custom, locally calibrated model trained on MAG's own ground-truth data, designed to capture regional traffic behavior rather than apply generic national benchmarks. The findings are documented, specific, and directly relevant to any agency navigating the same question.