How these numbers are made.

1 · Collection

We run automated collectors that read each agency's published feed on a fixed schedule and store the response exactly as received. We do not scrape pages built for humans where a machine-readable feed exists, and we identify ourselves in our requests.

What	Source	Read every	Licence
Canada–US border waits	CBSA (into Canada) · U.S. CBP (into the US)	10 minutes	Open Government Licence – Canada · US public domain
Airport customs volumes	CBSA open data	On each release	Open Government Licence – Canada
Canadian security waits	CATSA published checkpoints	5 minutes	Directory of official sources
Ground stops & delays	FAA	5 minutes	US public domain
Airport rankings	FAA · Statistics Canada · ACI	On each release	Public domain · StatCan open licence
Ontario school buses	Six transportation consortia	10 minutes	Public consortium boards

2 · What we store

Every reading is written to an append-only archive with the time we captured it and the timestamp the agency attached to it. We keep the raw response, not just our interpretation of it, so any figure we publish can be traced back to the exact bytes an agency served. That archive began on 25 July 2026 and grows continuously.

This is the part that makes the rankings possible. An agency tells you the wait right now; our archive lets us say whether that is normal for a Tuesday in August.

3 · How the figures are calculated

Average wait

The mean of all readings for that crossing or checkpoint over the stated period, including readings of zero. Because most crossings are clear most of the time, this number is usually low — it describes the typical moment, not the typical bad moment.

Probability of a wait

The share of readings greater than zero. This answers "how often is there any delay at all", which is a different and often more useful question than the average.

Average when delayed

The mean of readings greater than zero only — how long the wait tends to be when there actually is one.

P95

The value below which 95% of readings fall: a bad-day figure. Useful when you need to know your realistic worst case rather than your typical case.

Busiest period

The day-of-week and hour combination with the highest mean wait across the archive.

4 · Rules we hold ourselves to

• No invented numbers. Every published figure derives from agency data. We publish no estimates, projections or modelled values anywhere on this site.
• No "real-time" claims. See the FAQ below — the agencies publish roughly hourly and we say so.
• Gaps stay visible. Missing data is shown as missing, never filled in.
• Agency wording is relayed verbatim. Where a consortium or agency writes a notice, we pass on their words rather than paraphrasing them.
• The agency wins. If our board and the official source disagree, trust the official source. We link it on every page.

5 · Limits you should know about

• We are only as current as the agency. If CBSA publishes hourly, an hourly figure is the best that exists — from us or anyone.
• Coverage is uneven. Some crossings have no feed in one direction; some US airports publish no security data at all. We list these rather than hide them.
• Historical data has a start date. Our archive begins 25 July 2026. Where we use an agency's own historical release, we say which release and its period.
• Occasional network blocks. One or two sources refuse connections from our data centre. Where that happens we say so on the page and link the official board directly.

6 · Corrections

We correct errors on the page itself and note what changed. If a figure looks wrong, tell us through the contact page with the page and what you observed — that is genuinely useful to us.

Questions

How often does Transit Barometer update?

Our collectors read each official feed every 5 to 10 minutes depending on the source. The agencies themselves typically publish about hourly, so a fresher reading on our side does not mean fresher data — it means we capture the agency's update quickly. Every value shows the agency's own timestamp.

Is this data real-time?

No, and we never describe it that way. The agencies publish on their own schedule, usually around hourly. We show the timestamp the agency gave the reading so you can judge its age yourself.

What happens when a feed goes down?

The board says so. We show an explicit 'check the official source' state and link the agency page. We never display a stale reading as if it were current, and we never substitute an estimate.

Where does the historical data come from?

Two places. Some agencies publish historical open data, which we reprocess and cite. The rest is our own archive: we have stored every reading our collectors have taken since 25 July 2026, which lets us show patterns that are not available anywhere else.