Traffic signals are an everyday part of travel, but the seconds drivers spend waiting at intersections add up quickly across an entire transportation network. During the peak commute hour alone, traffic signals account for an estimated 4.27 million hours of delay nationwide and that conservative estimate does not include the return trip home.
Understanding where those delays occur and why is essential for agencies looking to improve traffic flow, prioritize investments, and make better operational decisions.
The INRIX U.S. Signals Scorecard offers a nationwide, data-driven look at how signalized intersections are performing. In the webinar, U.S. Signals Scorecard, INRIX explores the latest findings and demonstrates how connected vehicle data can help transportation agencies benchmark performance and identify opportunities for improvement.
Measuring Traffic Signal Performance at a National Scale
One of the most significant aspects of the latest Signals Scorecard is its scale. INRIX evaluated 276,880 signalized intersections using eight weeks of representative data, two weeks from each quarter. The analysis was powered by approximately 10.5 billion vehicle observations, with each observation representing a vehicle passing through a signalized intersection.
The results provide insight across all 50 states, as well as approximately 2,500 counties and 411 Metropolitan Planning Organizations (MPOs).
That scale matters because traditional signal performance analysis can depend on infrastructure installed at individual intersections. INRIX instead uses connected vehicle and probe data to evaluate how vehicles move through intersections. This approach required no field detection equipment or communication with traffic signal controllers.
How Long Do People Wait at Traffic Signals?
The Signals Scorecard puts numbers behind an experience familiar to every driver. Across the signals analyzed, the average control delay was 20.1 seconds per signal visit, while the median delay was 16.1 seconds. Nationally, that performance corresponds to a Level of Service C.
The Signals Scorecard grades intersections from A through F based on control delay. Most signals fall within the A, B, and C categories, while D, E, and F signals can help highlight locations where further investigation or investment may be valuable. The webinar emphasized that context remains important: an intersection serving two major arterials should not necessarily be evaluated in the same way as one serving a lower-volume local roadway.
The data also shows significant geographic variation. According to the Signals Scorecard, Wyoming had the lowest statewide average control delay at 12.6 seconds, followed by Nebraska at 15.2 seconds and Iowa at 15.6 seconds. At the other end, Washington, D.C. recorded an average of 28.8 seconds, followed by Nevada at 23.8 seconds and Florida at 23.6 seconds.
Going Beyond a Simple Ranking
The value of the Signals Scorecard goes beyond identifying which locations have the longest or shortest waits. Users can explore measures including average and median delay, peak-hour delay, Level of Service, and arrivals on green which is a coordination metric indicating how often vehicles progress through an intersection without stopping.
The interactive Signals Scorecard also provides state, county, and MPO views, maps of individual intersections, quarterly trends, and demand patterns by time of day and day of week. These tools can help transportation professionals move from a broad national benchmark to specific locations that deserve closer analysis.
Turn Data Into Better Signal Decisions
The Signals Scorecard demonstrates what is possible when connected vehicle data is applied at scale. Rather than relying only on periodic studies or infrastructure at selected intersections, agencies can gain a broader view of network performance and use consistent metrics to guide conversations about where improvements could have the greatest impact.
For transportation agencies, planners, engineers, and anyone interested in understanding how America moves through signalized intersections, the webinar provides a closer look at the Scorecard’s methodology, findings, trends, and practical applications.
Watch the on-demand U.S. Signals Scorecard Webinar or read the report.