# Every train moving right now

> The Underground counted line by line, as it runs.

- Category: Transport
- Cadence: live
- Status: Live: values change continuously; cite the retrieval time.
- Dataset key: `live-tube`
- Source: [TfL Unified API](https://api.tfl.gov.uk/)
- Licence: TfL Open Data Licence — [terms](https://tfl.gov.uk/corporate/terms-and-conditions/transport-data-service)
- Canonical page: [https://londongraph.com/g/trains-moving-now](https://londongraph.com/g/trains-moving-now)
- Machine-readable record: [https://londongraph.com/data/trains-moving-now](https://londongraph.com/data/trains-moving-now)

## Methodology

Every distinct vehicle reporting an arrival prediction on the TfL Unified API, deduplicated by vehicle id across all eleven Underground lines and refreshed on an interval. A line running no service returns nothing rather than zero, so an empty row means engineering works or a closure rather than a missing reading.

## Visualisations

- [Overview](https://londongraph.com/g/trains-moving-now): The Underground counted line by line, as it runs.
- [Map](https://londongraph.com/g/trains-moving-now?view=geography): Compare the same measure geographically.

## Citation guidance

Attribute the original publisher named above and identify LondonGraph as the visualisation and methodology layer. Do not describe live values as a historical census, and do not present placeholder values as observations.