TLMS Live Vehicle Positions

Overview

TLMS (Transit Live Mapping Solutions) is a community project that tracks vehicles in real time by receiving the R09 radio telegrams trams and buses transmit for traffic light priority (VDV 420). Software-defined radio receivers around the city decode these telegrams and TLMS publishes the resulting vehicle positions through a public WebSocket and several HTTP APIs.

For Dresden this yields live positions of DVB vehicles, including line, run number and delay. The data is independent of VVO/DVB systems, but coverage depends on receiver placement and only vehicles that emit R09 telegrams show up. Positions are interpolated between reporting points.

A live map is available at kid.tlm.solutions/de/map/0 (the 0 is the region ID for Dresden).

⚠️ TLMS is a volunteer-run community project without availability guarantees. The full stack is open source at github.com/tlm-solutions, documentation lives at docs.tlm.solutions.

WebSocket Endpoint

wss://socket.tlm.solutions

Vehicle position updates start streaming as JSON messages immediately after connecting, one JSON object per message. No authentication is required.

Quick Start

websocat wss://socket.tlm.solutions

{
  "source": 1,
  "time": "1786535656711",
  "lat": 51.048192923076961,
  "lon": 13.743153307692344,
  "line": 62,
  "run": 4,
  "delayed": 120,
  "r09_reporting_point": 11266,
  "r09_destination_number": 232
}

Message Format

Messages correspond to the TLMS Waypoint struct:

Field	Type	Description
`id`	Integer	Unique waypoint identifier (not always present)
`source`	Integer	Data source: `0` unknown, `1` R09 telegram, `2` GPS via Trekkie
`time`	String	Unix timestamp in milliseconds (serialized as string)
`region`	Integer	Region ID (present when subscribed to multiple regions)
`lat` / `lon`	Float	Vehicle position (interpolated between reporting points)
`line`	Integer	Line number (e.g. `3`, `62`)
`run`	Integer	Run number (“Kurs/Laufnummer”) identifying the vehicle on its line
`delayed`	Float	Delay in seconds, negative values mean the vehicle is early (optional)
`r09_reporting_point`	Integer	ID of the reporting point the telegram was sent from (optional)
`r09_destination_number`	Integer	Destination number from the R09 telegram (optional)

Filtering

Send a JSON filter object to the socket to narrow the stream. Sending another filter overwrites the previous one.

{
  "lines": [9, 11],
  "positions": [],
  "regions": [0],
  "enrich": true
}

Field	Description
`lines`	Only emit updates for these line numbers (empty = all)
`positions`	Only emit updates for these reporting point IDs (empty = all)
`regions`	Only emit updates for these region IDs (e.g. `0` = Dresden)
`enrich`	Request enriched waypoints (currently returns the same fields)

Example — only Dresden trams on line 3:

echo '{"regions": [0], "lines": [3]}' | websocat -n wss://socket.tlm.solutions

Regions

Region metadata is available from the Datacare API:

curl https://datacare.tlm.solutions/v1/region

Dresden is region 0. Other regions (Chemnitz, Hannover, …) exist with varying degrees of coverage.

TLMS also runs Swagger-documented REST APIs:

Service	URL	Purpose
Datacare	datacare.tlm.solutions/swagger-ui/	Regions, stations and R09 telegram data
Lizard	lizard.tlm.solutions/swagger-ui/	Current network state (live vehicle state)
Trekkie	trekkie.tlm.solutions/swagger-ui/	GPS track submission and retrieval