OpenStreetMap import
From OpenStreetMap to a running traffic simulation
Road Mesh turns raw OpenStreetMap data into an editable, routable traffic model you can simulate in the browser. Search a place, choose an import area and road classes, and the network is fetched live from the Overpass API — then cleaned into lanes, junctions and signals you can edit before running traffic over it.
Import a real network in minutes
Start by searching any place on the built-in map and drawing an import area. Pick which OSM road classes to include — from motorways down to service roads — and Road Mesh fetches the current OpenStreetMap geometry for that area through the Overpass API. Original OSM way IDs and tags are preserved so every road stays traceable back to its source data.
Automatic network cleanup
Raw OSM ways are not a simulation network, so imported geometry is normalized automatically:
- Ways become editable centerline splines in a local, meter-based coordinate system.
- Lane counts and directions are inferred from OSM tags, with validation warnings where the data is ambiguous.
- Junctions are detected from topology; multi-node signalized crossings are clustered into unified junction areas with curved lane connectors for turn movements.
- Likely signalized junctions receive coordinated multi-phase signal timings, including protected left turns.
- Motorway ramps are connected to their merge and diverge lanes automatically.
- A routable lane graph is built for vehicle routing and simulation.
Edit before you simulate
The imported network is a model, not a picture. Move geometry, change lane counts and speed limits, draw new roads, close lanes or whole segments, swap junction control between uncontrolled, signalized, roundabout and ramp merge/diverge templates, and retime signals — all with full undo and redo.
Add demand and run the microsimulation
Place traffic sources on lanes, assign destinations with traffic ratios, and set demand for each source. The deterministic fixed-step microsimulation moves individual vehicles with established car-following and lane-change models (IIDM with CAH, and MOBIL), route-aware lane preparation ahead of turns and exits, coordinated signal response, and closure-aware rerouting. Queue-length and throughput metrics update while the simulation runs, so you can compare a baseline against an edited scenario.
Good to know
- Network quality follows OpenStreetMap quality: where lane or speed tagging is missing, Road Mesh infers defaults and flags them for review.
- Each plan has a maximum import area per imported network — see pricing for current limits.
- Overpass API availability can affect import times for very large or busy areas.