Table of Contents
OpenTrafficMap Wiki
OpenTrafficMap is an open project for visualizing and analyzing C-ITS data (Cooperative Intelligent Transport Systems). Its goal is to make visible which data traffic lights, trams, buses, and modern cars are already transmitting unencrypted today.
Live map: https://opentrafficmap.org
Code: https://codeberg.org/opentrafficmap
What is C-ITS?
C-ITS stands for Cooperative Intelligent Transport Systems: vehicles and infrastructure communicate with one another.
More details can be found on the C-ITS page.
With your help, we receive C-ITS messages and display them on our map.
Contributing to the map
Since C-ITS can only be received over a few hundred meters up to a few kilometers, we can only show live data if at least one receiver is nearby. We use the ESP32-C5, which costs only a few euros and offers good reception with the PCB antenna of the ESP32-C5-WROOM module.
We have developed a board on which the ESP32-C5 is connected to an SPI-to-Ethernet chip and which can be powered via PoE. With a 3D-printed enclosure, the receiver board can be mounted outdoors (the higher, the better).
There are several ways to get a receiver:
- Order one yourself from any PCB manufacturer (Gerber, BOM, and CPL files: opentrafficmap/its-g5-receiver/releases)
- Wait for our group order
- Build a receiver yourself using an ESP32-C5 dev board (readily available online in Europe)
If you build a receiver yourself, there are also several ways to feed the data into OpenTrafficMap:
- Connect it directly to the internet with an SPI-to-Ethernet chip (W5500, ENC28J60): opentrafficmap/its-g5-receiver-firmware
- Connect it to a Raspberry Pi via USB / UART with this project: jstsmthrgk/simple-its-g5-receiver-firmware
- Connect it to an Android phone via USB with this project: sascha8a/cits-to-go
- with the ESPHome/Home Assistant integration: https://github.com/hn/esphome-its-g5
More information about the MQTT server and the (optional) node registration: Node Registration
Group order
At the beginning of April, we ordered 200 fully assembled C-ITS receivers. We expect them to arrive in mid-May 2026. We pass the boards on at cost price for €20, including a 3D-printed enclosure. As soon as the boards have arrived, we will open a Pretix shop where you can place your order. We plan to offer the following options:
- Pickup at realraum in Graz (after confirmation that the receiver is ready for pickup)
- Shipping within Austria (€4.20 shipping, via GLS)
- Shipping to Germany (€10.90 shipping, via GLS)
- Shipping with your own Post.at / GLS / DPD parcel label (free)
To take part in the group order, you can place an order in our Pretix shop here: pretix.opentrafficmap.org
Documentation
- Getting Started — unboxing, power supply, first steps
- C-ITS background: What is C-ITS, Who is sending C-ITS?
Talk at Grazer Linuxtage
We gave a talk (in German) at Grazer Linuxtage 2026, titled: C-ITS: Tracking traffic lights, trams, and cars with an ESP32
