Desk
Quality & Compliance
Validation, conformance, feed health, and reporting such as NTD and SB125.
03entries
On this desk
Explainers
Explainer
Bus bunching and headway: why three arrive at once
Three buses arriving nose to tail is not bad luck. It is a feedback loop in frequent service, where a late bus falls further behind and the one behind it catches up. Here is the mechanism, why agencies measure headway instead of schedule, and what they do about it.
Explainer
Ghost buses: why the app shows a bus that never comes
A ghost bus is a prediction with no vehicle behind it. Here is how a transit app generates one, the four ways it happens, and how Chicago drove its rate down.
Explainer
What the National Transit Database actually holds
The NTD is the federal record of US public transit: who rides, what it costs, and who has to report. Here is what it holds, who files it, and how to pull the numbers yourself.