Move the mouse: travel times on foot, by bike, by car or by public transport are recomputed at every move, and the map lights up from green (close) to red, then violet (far).
▶ Open the demo · How it works · desktop browser recommended
| 13 | 18 M | 14,000 | 0 |
|---|---|---|---|
| regions of metropolitan France | road sections | public transport lines | server: everything runs in your browser |
Data from the IGN Géoplateforme (BD TOPO, Plan IGN, geocoding) and transport.data.gouv.fr (timetables). Computed in the browser by a Rust engine compiled to WebAssembly: the whole region in a few milliseconds.
- Hover anywhere: the map is recolored from the cursor. Click to pin a point, then hover a destination for the route and the trip step by step.
- Choose the mode, the hour, departure or arrival, the maximum time; buildings in 3D follow the cursor too.
- Simulate a closure (a metro section, a street) and see the stations that lose more than 5 min.
- Compare the modes on one trip, search an address, share the view by its link.
A proof of concept, for comparing places and modes, not for planning to the minute:
- transit: average waits on a typical weekday, not the exact timetable;
- car: a typical congestion curve, no live traffic;
- walking and cycling slowed down on slopes, from the BD TOPO heights;
- footpaths and service roads only in the main city centres.
The literature behind each model, with figures and formulas: How it works and docs/engine.md.
One map takes it 1 to 3 s (12 to 15 isochrone requests, about 5 accepted per second); following the mouse needs 30 to 60 maps per second, and it has no public transport. So the data comes from the Géoplateforme and the computation runs in the browser; the route service stays the reference, shown beside our time in the trip panel. A one-to-many service (travel time matrix) or a downloadable routing graph would let the Géoplateforme serve it directly.
| Data | Source | Licence |
|---|---|---|
| Roads and buildings (BD TOPO), basemap (Plan IGN), hillshade (RGE ALTI), addresses | IGN, Géoplateforme | Licence Ouverte Etalab 2.0 |
| Public transport timetables | transport.data.gouv.fr (Île-de-France Mobilités, regional aggregates, SNCF) | per feed, mostly ODbL or Licence Ouverte |
Region by region: web/public/data/README.md. Published by IGN, a proof of concept, not an official service; no account, no cookie: legal notice.
Requirements: Bun; git-lfs for the largest region file. The data and the compiled engine are in the repository: no Rust needed to run the app.
bun install
bun run dev # http://127.0.0.1:5173
bun run build # static site in web/dist
bun run typecheck && bun run lintweb/ React + MapLibre app (Vite, @ign-junn/design-system); src/features/ one folder per feature
crates/engine/ travel time engine, Rust → WebAssembly
crates/prep/ Rust tool: BD TOPO roads and GTFS timetables → the network files of a region
scripts/ engine build, benchmarks, calibration
docs/ technical documentation
Change the engine (Rust, rustup target add wasm32-unknown-unknown): bun run engine, cargo test --workspace,
cargo clippy --workspace --all-targets; time it with bun scripts/benchEngine.ts [region].
Rebuild the data: bun run data -- <region>|all (roads) and bun run transit -- <region>|all (timetables); the
downloads are cached in .cache/. The outlines of the regions (which one a searched place is in) come from
bun scripts/regionShapes.ts.
Deployment: every push to main publishes the site on GitHub Pages.
Details: architecture, engine, rendering, data formats.