# France Roadshow data notes

The compact text instance contains everything needed to reproduce the official score. The JSON file adds city display names, geographic coordinates, source metadata, and simplified map geometry for the visualization.

## Coordinates

All scoring coordinates are planar kilometres in EPSG:3035, translated so that Paris is the origin. Route lengths and coverage distances are Euclidean in this coordinate system.

## Population

Population weights come from the INSEE 2021 population grid. The source 1 km cells are deterministically combined into 5 km cells to keep the challenge data and visualization compact. Population is preserved by the aggregation.

Eligible cities are the 1,200 most populous communes in the frozen API Découpage administratif snapshot for continental metropolitan France. Commune population is used only to select this candidate set; it is not added directly to the score.

Sources:

- [INSEE 2021 population grid](https://www.insee.fr/fr/statistiques/8272002)
- [API Découpage administratif](https://geo.api.gouv.fr/decoupage-administratif/communes)

Both sources are published under Licence Ouverte 2.0. The website uses only the frozen files distributed with this problem and never calls a live service while scoring.