How Leavecast measures airport wait times

Leavecast is a measurement project. We do not estimate security waits from crowd-sourced guesses or stale averages — we record what official sources report, every five minutes, around the clock, and we keep every reading.

What we poll, and how often

Every five minutes our collectors query four kinds of sources. First, TSA wait-time feeds: the checkpoint wait figures airports and the TSA publish for standard and PreCheck lanes. Second, FAA National Airspace System status: ground stops, ground delay programs, and closure advisories that affect when your flight actually leaves. Third, National Weather Service forecasts for the grid point covering each airfield, because weather drives both airport delays and your drive to the terminal. Fourth, CBP customs data: official arrival-processing wait times for international airports. Each reading is stamped with the moment it was observed and appended to a permanent archive — nothing is overwritten, smoothed, or backfilled.

What the numbers mean

When an airport page says the security wait is 25 minutes, that is the most recent figure a source reported, and the page tells you how many minutes old the reading is. Our when-to-leave guidance combines that live wait with typical patterns we have recorded for that airport at that hour and day of week.

Honest limitations

Not every airport publishes live checkpoint waits. Some airports in our registry have no live security-wait coverage at all; for those we show typical patterns and clearly label the absence of a live reading rather than inventing one. CBP customs data lags roughly 48 hours behind real time, so customs figures describe recent conditions, not this moment. And any feed can go quiet — when a source stops reporting, we show the age of the last reading instead of pretending it is current.

The accuracy scorecard promise

Because we archive every reading, our track record is checkable. We publish an accuracy scorecard comparing what we showed travelers against what the sources subsequently reported, airport by airport — and we will keep publishing it even when the numbers are unflattering. If our data for an airport is thin or unreliable, the scorecard will say so.

Leavecast is not affiliated with the TSA, FAA, NWS, CBP, or any airport.