Every county in America, ranked.
A county-level rollup of observed signalized intersections: all signals spatially joined to county boundaries at ingest, then ranked by delay, peak-hour performance, arrival on green, and sampled crossing density. Methodology sits at the bottom of the page.
Top 10 smoothest counties
Lowest average control delay.Top 10 counties with the lowest signal progression
Lowest arrival on green.National county leaderboard
Search by county or state. Click any column header to sort. Default order: lowest average delay first.| # | County | State | Signals | LOS | Avg delay | Peak-hour LOS | AOG % | Daily obs / signal |
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About these metrics
All figures are derived from INRIX Signal Analytics: anonymized GPS pings from connected vehicles passing through signalized intersections, sampled across eight representative weeks of 2025. They are probe-based performance measures, not full traffic volumes. Full definitions, the data window, and Level of Service thresholds are documented on the methodology page.
Peak hours are rolling 60-minute windows stepped every 15 minutes. For each intersection we evaluate weekday AM, weekday PM, and weekend candidate windows separately and select the window with the highest average control delay as that intersection's peak. State composition aggregates those per-intersection peaks; the "typical" window cited in each caption is the modal window across states.