Content
# aria-mcp-trafik-dk
A [Model Context Protocol (MCP)](https://modelcontextprotocol.io) server that exposes current Danish road traffic events and roadworks to AI assistants. Built for [ARIA](https://github.com/kimhjort/aria) and shareable with the community.
**Fully keyless** — the data source is a public GCS-hosted JSON feed served by Vejdirektoratet as the backend for [trafikkort.vejdirektoratet.dk](https://trafikkort.vejdirektoratet.dk) (trafikinfo.dk).
Complements `aria-mcp-drivetime-dk`: that server computes drive time; this one tells you whether the road is clear.
## Data Source
| Source | What | Attribution |
|---|---|---|
| [Vejdirektoratet](https://www.vejdirektoratet.dk) / [trafikinfo.dk](https://trafikkort.vejdirektoratet.dk) | Current traffic events, roadblocks, queues, roadworks, critical announcements | Danish Road Directorate — free public traffic data |
**NAP reference:** [https://nap.vd.dk](https://nap.vd.dk) (National Access Point for road data, Denmark)
### Endpoint details
The app at `trafikkort.vejdirektoratet.dk` is backed by two public GCS-hosted JSON feeds (discovered by reading the app's JavaScript bundle):
| File | URL | What |
|---|---|---|
| `big-screen-events.json` | `https://storage.googleapis.com/trafikkort-data/geojson/big-screen-events.json` | All current incidents, accidents, roadblocks, queues, closures, weather-related events (~3 min cadence) |
| `critical-announcements.json` | `https://storage.googleapis.com/trafikkort-data/geojson/critical-announcements.json` | Major planned roadworks and critical traffic announcements |
Both are plain JSON (GeoJSON-derived), no authentication required, no API key.
### Data format
`big-screen-events.json` is an **array of GeoJSON FeatureCollections**, one per event (each collection has exactly one feature). Each feature carries:
```json
{
"type": "Feature",
"geometry": { "type": "Point", "coordinates": [lon, lat] },
"properties": {
"featureId": "...",
"layerId": "layer_id_19H1",
"title": "Kør forsigtigt",
"header": "Kør forsigtigt - E45 fra Randers mod Aalborg ...",
"description": "<p>HTML description</p>",
"TrafficMan2_Type": "org.vd.trafficmap.datexii.v32.datamodel.GeneralInstructionOrMessageToRoadUsers",
"beginPeriod": "13-06-2026 kl. 00:12",
"endPeriod": "13-06-2026 kl. 02:00",
"kommune": "Vejdirektoratet",
"suspended": "false",
"future": "false",
"visible": "true"
}
}
```
The outer FeatureCollection also carries `layerName` which classifies the event:
| `layerName` | Meaning |
|---|---|
| `current-other-traffic-announcements.point` | General incidents, accidents, obstructions |
| `current-roadblocks.point` | Road/lane closures |
| `current-queue.point` | Traffic queues |
| `current-blocking-events.point` | Public events with road closures |
| `current-slippery-road.point` | Slippery road / water on road |
| `current-strong-wind-traffic-announcements.point` | Strong wind warnings |
| `current-blocking-roadwork.point` / `current-roadwork.point` | Active roadworks (when present) |
`TrafficMan2_Type` is a DATEX II v3.2 class path (e.g. `...Accident`, `...AbnormalTraffic`, `...MaintenanceWorks`).
`critical-announcements.json` is a single FeatureCollection with properties: `featureId`, `title`, `description` (HTML), `category`, `validFrom` (ISO datetime).
### Fragility notes
- The GCS bucket (`trafikkort-data`) is public but not officially documented. It has been stable since at least 2020 (the mobile SDKs reference the same domain). URL changes are possible with app updates.
- The subdirectory `geojson/25832/` (EPSG:25832 projected coordinates) is **not** publicly accessible — only the `geojson/` root files are open.
- Events arrive as individual FeatureCollections (one per event), so the array length in `big-screen-events.json` equals the event count (typically 100–300).
- `description` contains HTML; this server strips it before returning.
- `beginPeriod` / `endPeriod` are Danish-formatted date strings (e.g. `"13-06-2026 kl. 00:12"`), not ISO — returned as-is.
- `suspended: "true"` means the event is stored but currently inactive (e.g. cleared accident). This server includes suspended events but marks the flag.
## Install & Run
```bash
npx aria-mcp-trafik-dk
```
Or install globally:
```bash
npm install -g aria-mcp-trafik-dk
aria-mcp-trafik-dk
```
Requires Node.js 20 or later.
## Tools
### `traffic_events`
Fetch current Danish road traffic events.
**Parameters:**
| Name | Type | Required | Description |
|---|---|---|---|
| `area` | string | No | Free-text region/road filter, e.g. `"E45"`, `"Horsens"`, `"Fyn"` |
| `type` | string | No | `"all"` (default) \| `"incident"` \| `"roadwork"` \| `"queue"` |
**Returns:** Array of traffic events:
```json
[
{
"type": "Traffic message",
"road": "E45 fra Randers mod Aalborg",
"location": "Kør forsigtigt - E45 fra Randers mod Aalborg mellem <35> Hobro V og <34> Hobro N",
"description": "E45 fra Randers mod Aalborg mellem <35> Hobro V og <34> Hobro N Havareret køretøj, Pas på I højre spor, vejhjælp er på vej",
"from": "13-06-2026 kl. 00:12",
"severity": "warning",
"suspended": false,
"coordinates": [9.733868, 56.66633]
}
]
```
---
### `roadworks`
Fetch planned and ongoing roadworks.
**Parameters:**
| Name | Type | Required | Description |
|---|---|---|---|
| `area` | string | No | Free-text region/road filter |
**Returns:** Mixed array of `TrafficEvent` objects (from live roadwork layers) and `CriticalAnnouncement` objects (from `critical-announcements.json`):
```json
[
{
"id": "9349df74-15e8-4ffc-93e7-e3e236720da9",
"title": "E45 Østjyske Motorvej spærres ved Horsens",
"description": "I forbindelse med bronedrivning spærres E45 Østjyske Motorvej ...",
"category": "Trafikal forsidemelding (trafikkort)",
"validFrom": "2026-06-12T10:56:00.410Z"
}
]
```
---
### `events_near`
Find traffic events within a radius of a geographic point.
**Parameters:**
| Name | Type | Required | Description |
|---|---|---|---|
| `lat` | number | Yes | Latitude (WGS84) |
| `lon` | number | Yes | Longitude (WGS84) |
| `radiusKm` | number | No | Radius in km (default 25, max 200) |
**Returns:** Array of traffic events, each with an added `distanceKm` field, sorted by distance ascending.
```json
[
{
"type": "Road/lane closure",
"road": "E45 Østjyske Motorvej",
"location": "...",
"description": "...",
"severity": "blocking",
"suspended": false,
"coordinates": [9.85, 55.86],
"distanceKm": 2.3
}
]
```
## Environment Variables
| Variable | Description |
|---|---|
| `VD_GCS_BASE` | Override the GCS base URL (for testing or caching proxies). Default: `https://storage.googleapis.com/trafikkort-data/geojson` |
## ARIA MCP Config
Add to your ARIA credentials / MCP config:
```json
{
"command": "npx",
"args": ["-y", "aria-mcp-trafik-dk"],
"env": {}
}
```
No environment variables are required. Pair with `aria-mcp-drivetime-dk` for a complete pre-drive check:
```json
[
{ "command": "npx", "args": ["-y", "aria-mcp-drivetime-dk"] },
{ "command": "npx", "args": ["-y", "aria-mcp-trafik-dk"] }
]
```
## Development
```bash
git clone https://github.com/kimhjort/aria-mcp-trafik-dk
cd aria-mcp-trafik-dk
npm install
npm run build
npm test
```
## License
MIT — see [LICENSE](LICENSE).
Traffic data is public information from Vejdirektoratet (Danish Road Directorate). Attribution to Vejdirektoratet / trafikinfo.dk is appreciated when redistributing.
