I recently came across a Hacker News thread describing a project called “OpenTrafficMap”.
The project appears to be a Austrian(?) project that uses a hardware device to pick up openly broadcast signals from both vehicles are infrastructure (like traffic signals) to build a heatmap of traffic.
As best I can understand, some vehicles (cars, buses, trams) and infrastructure emits 5GHz signals using a protocol called C-ITS/ITS-G5, which the ESP32-C5-based hardware picks up. Then it “pipes raw 802.11 packets from a NATS connection into wireshark (tshark) and sends a json version of the packet back to the NATS server”, which is then used to feed the live map.
It’s unclear to me whether this feature is present in vehicle in the USA, but the project seems very interesting!
They have a repo here for the hardware and firmware:
And videos (German language) of their Grazer Linux-Tage talk here:
https://www.youtube.com/watch?v=gje6RnskBNA
https://media.ccc.de/v/glt26-688-c-its-mit-einem-esp32-ampeln-straenbahnen-und-autos-tracken
I do not speak sufficient German to get much from the video, though someone posted an AI transcription/translation here, if folks are interested: # C-ITS: Tracking Traffic Lights, Trams, and Cars with an ESP32Source: https - Pastebin.com