For a while I tried creating traffic-light-free bicycle routes from my home in the suburbs to my office in Amsterdam center (because intersections, especially with trams, can sometimes take a long time.
Unfortunately there was no API with data on which intersections have traffic lights and I had to build these routes manually in Strava using satellite images.
I did learn in the process that some traffic light data is actually available from the government, but only for selected partners. The Flitsmeister app for example has it and shows at some traffic lights how long it will take for the light to turn green (in a car, not on a bicycle)
alex_duf 2 hours ago [-]
Rotterdam is using rain data to asjust traffic lights. Bicycles are waiting less at intersections. They also make the amber light longer to give you time to break for farther away and avoid a fall.
Found out about this today, up until now 802.11p hardware is very expensive, and so you cannot easily do anything with V2x messages like CAM or SPAT, but the fact this was done with sub £20 hardware is really interesting.
rompic 6 hours ago [-]
Fully agree. That's the most interesting thing about this.
How does the hardware work? It seems like there isn't any radio hardware other than the ESP, so that can natively receive the ITS-G5 messages? Why not just use an ESP board with native ethernet then?
rompic 6 hours ago [-]
They are doing it with the standard WIFI receiver.
Currently they are sending the Wireshark dumps to a backend for processing.
According to their presentation they are working on a rust firmware to do everything on the board.
maelito 3 hours ago [-]
We need global open congestion data. At least on the european scale.
It's important so that alternatives to Google Maps and Waze (Google) can emerge.
To create congestion data, one needs to own an OS with location tracking, or be an international mobile network. Won't happen.
[disclaimer : I work on an open source alternative to big tech's maps]
danelski 48 minutes ago [-]
In my experience, the congestion data is not the issue: even with the split across Google / TomTom / Here / Apple / some hyperlocal alternatives, everyone seems to have reasonably good idea where the traffic jams are. Having up to date POIs is a different can of worms only solved by Google, not by some clever algo, but through the sheer brand recognition. They're the only ones that have this data fed to them by POI owners.
cheschire 1 hours ago [-]
How would you overcome the data source trust issue? In open data collection you either fingerprint the data to ensure validity or you anonymize the data to provide security, but striking the balance between the two seems like the biggest of hurdles in an effort like this.
The risk of the data being invalid seems as risky as the privacy implications in this case.
crimsoneer 2 hours ago [-]
What is the OS alternative? OSM?
maelito 2 hours ago [-]
https://cartes.app. Based on OSM of course, but OSM is just a geographical database, with lots of incomplete UIs built on top by the community. Cartes is one of them, we're trying to make it complete and modern :)
yosamino 2 hours ago [-]
That looks pretty cool - sorry to have a complaint immediately:
When opening the map on Firefox/Linux zooming to like a France-size view and then not doing anything, the view keeps scrolling up and down relatively slowly, but very annoyingly.
Zooming all the way out, it looks like the globe is jiggling back and forth ever so slightly, but continually.
I've recently seen this happen on another mapping application ( cannot remember which one) so it's probably in down the stack somewhere in a library you are using.
Huge performance issues for me trying to use it on Chrome. But I like the idea.
solarpunk 16 hours ago [-]
Cool, but it there's no links for more info, and it doesn't seem to work in the USA at all.
uyzstvqs 13 hours ago [-]
The site is definitely lacking. It's half in German, half in English.
The concept is that there is this protocol called ITS-G5, which is a European profile of 802.11p. Vehicles and traffic infrastructure can transmit telemetry on 5 GHz. Other vehicles and traffic infrastructure can use it for situational awareness.
This website collects that data using local receivers and aggregates it onto a map, similar to what website like ADSB-Exchange do with ADS-B.
What is concerning is that vehicles appear to broadcast a MAC address. Does this mean that ITS-G5, 802.11p, and C-ITS could be used for persistent tracking?
wumms 3 hours ago [-]
> What is concerning is that vehicles appear to broadcast a MAC address.
Reading the translation of the talk, public transport vehicles have a persistent MAC but for private cars the MAC address changes every 15 minutes.
rompic 6 hours ago [-]
As discussed in the video they are not resetting the packet sequence number though, making it easy to match them with the other data transmitted.
ufocia 12 hours ago [-]
That still doesn't seem very private.
fy20 6 hours ago [-]
For a vehicle with a highly visible unique identifier on the front and rear? In my country basically every private carpark has ANPR cameras, the tech is dirt cheap now.
Particularly anywhere rural or off the beaten path
moooo99 5 hours ago [-]
You wouln‘t really have the kind if hardware there. The communication relies on a multi hop mesh that would‘t work anywhere without sufficient coverage.
izacus 5 hours ago [-]
You do know you have a unique ID displayed on a big tab on the vehicle, right?
13 hours ago [-]
antman 8 hours ago [-]
What about the traffic lights on the map do they also have transmitters?
moooo99 5 hours ago [-]
Yes, they also have transmitters. The traffic lights send out MAPEM and SPATEM messages. They describe the layout of the lanes at the intersection as well as the red/green phase timings of the signal.
In Graz, the city where the authors live, there are 165 of such signals planned.
alexpotato 13 hours ago [-]
This should be a top level comment as it has a ton of useful info and can be voted to the top.
firesteelrain 11 hours ago [-]
Did they re invent APRS?
moooo99 16 hours ago [-]
The project was shared as part of a talk at Graz Linux Tage. You can find it here, unfortunately it is only available in German
Happy to see this popping up here, I watched the Linux Tage talk last week. The demo just kept getting better and better, to a point where the audience just interruptively cheers and claps away. I know nothing about the contents, but this warmed my heart. True hacker project!
RobotToaster 15 hours ago [-]
Is there a link to the hardware they mention in the description?
Maxious 8 hours ago [-]
They built their own circuit board but the core module that does the 802.11p is just a ESP32-C5
RobotToaster 7 hours ago [-]
Yes, I understand that. The translation makes it sound like they have published the software and design, or are somehow making boards available.
>To improve coverage, we need your support! We have built a board with *ESP32-C5* and *PoE* that allows you to capture *C-ITS* packages yourself, and provide us for our face-up card, or process it yourself.
It's based on Car2X/Vehicle2X data that's sent unencrypted and can be received with chips you can order from China.
rootusrootus 16 hours ago [-]
Will be interesting to see how it fares when it does come to the US. It seems like there are some cars that already have the tech installed. But the US is allegedly more interested in the cellular version, which I am guessing is not as easy to pick up with a simple receiver?
My gut feeling is that this seems like one of those things likely to face a lot of backlash when it becomes widely known.
felixguendling 16 hours ago [-]
I guess we only find out if some people order those chips and check if there is some data. From my understanding the idea is the same like maps showing air planes or ships (for ships it’s AIS). So without volunteers/pioneers who participate we won’t know. It seems like traffic lights and trams also can send data.
walrus01 16 hours ago [-]
If I had a dollar for every time I've seen an American on the Internet assume that anything published in the English language must be US-centric...
bravoetch 16 hours ago [-]
You still wouldn't have nearly as many dollars if you subtracted the times those people were correct in that assumption. Personally I assumed the site would be global. It doesn't have any info though, so I rely on finding out somewhere else I guess.
lucideer 14 hours ago [-]
> Personally I assumed the site would be global
The only reason you would assume a site would be global is if your definition of "global" is "works in the US" & you never bother to check for support of other countries. I live in the anglosphere outside of the US & I encounter more than enough US-only web projects for that not be to a default assumption I hold.
Most sites are not global - it's very odd to assume they would be.
BigToach 12 hours ago [-]
Another reason could be that calling this OpenTrafficMap gives an impression that it is similar to OpenStreetMap, which is global.
antalis 43 minutes ago [-]
Fun fact: OpenStreetMap started out with maps of only the UK.
OpenTrafficMap does support data from all around the world.
lucideer 3 hours ago [-]
OSM launched as a London / UK project. Even today, it's a lot more comprehensive in some parts of the world than others.
If I got the impression that it was like OSM, that would give me the impression that it is only as global as my contributions to it (which is what lead to OSM becoming global).
MrDrMcCoy 2 hours ago [-]
Expecting support globally is of course unreasonable. Expecting it to be designed to be somewhat location-agnostic for contributors and including some obvious docs (which could just be "coming soon" or "here's what we need to expand") is pretty reasonable to me.
I don't get why there isn't even a stub repo for a mobile app to contribute with. Or am I just not finding it?
After the talk on Grazer Linuxtage (media.ccc.de, youtube.com) we got many responses from people also wanting to buy this receiver. We fixed a few issues of the first revision and ordered 200pcs of Revision 2.
We expect the 200pcs to arrive in the first week of May, 2026. The cost of one complete receiver (excluding case and mechanical parts) is about 20 €.
If you want to purchase a receiver PCB, please contact us at the email liked in the Imprint/Impressum of opentrafficmap.org"
MrDrMcCoy 21 minutes ago [-]
That's for a hardware receiver. It does not appear to have mobile app or API doc accompanyment or a doc on what is needed for expansion. I would imagine that there is a minimum critical mass and municipal buy-in for such devices to work. Theoretically, mobile apps would require far less barriers to start being useful.
hamdingers 16 hours ago [-]
It seems pretty weird to use all English words in the domain for a service that offers no English translations and operates in no English speaking countries.
moooo99 15 hours ago [-]
The map is based on international standards and technically it does not restrict locations to German speaking countries.
The authors of this project also shared that they intend on publishing more around this project. This seems to be mostly an early demo that was intended for the live event.
13 hours ago [-]
walrus01 16 hours ago [-]
The Germans and Danes and Swedes and Norwegians I see on the Internet developing and publishing software often have a better grasp of the English language than many born in the USA Americans.
ufocia 12 hours ago [-]
That's true for Scandinavians, Germans are not as gut.
aspect0545 5 hours ago [-]
Ja ja, maybe not as gut as the Scandinavians, but still better than many US Americans.
bobomonkey 15 hours ago [-]
[flagged]
perching_aix 16 hours ago [-]
Is expecting something to work in the US the same as expecting it to be US-centric?
rootusrootus 16 hours ago [-]
Conversely, if I had a penny for every time someone complained about Americans... ;-)
dawnerd 7 hours ago [-]
That's one way to get rid of our (US) pennies now that they're useless!
mahsa32 4 hours ago [-]
I did scroll across to the UK and was disappointed that there's none for here.
But I'll probably add my own receiver soon!
amazingamazing 16 hours ago [-]
This is an American site to be fair. Mapbox is also an American company.
ufocia 12 hours ago [-]
It does have an English name, so why the surprise?
estimator7292 14 hours ago [-]
OpenStreetMaps works in the US and much of the rest of the world.
It's entirely reasonable to expect that a project with an extremely similar name would also work in most of the world, which just happens to include the USA.
exegete 16 hours ago [-]
I mean I don’t anyone thought this was in the US since the UI is not in English. Maybe it’s more of, this neat, wish we had it here?
modinfo 10 hours ago [-]
It will be nice if we everybody could just add own receivers, then it will be quickly cover more cities.
But still nice project.
modinfo 7 hours ago [-]
Ahh, it send automatically to website!
"mqtts://cits1.opentrafficmap.org"
Myzel394 3 hours ago [-]
I don't get this at all. Is this a live view of the traffic lights, buses, and more? How do they get the data?
poorman 14 hours ago [-]
I wonder if this could be used to track location of the vehicle
embedding-shape 14 hours ago [-]
Isn't that the point of the project? I'm seeing a bunch of tracked vehicles, although they all seem parked at the moment.
Does Graz not have night bus service?
flicken 8 hours ago [-]
The night bus service only runs the nights "before" Saturday and Sunday[1]. It's a small university city with 300k population (600k greater metropolitan area).
> It's a small university city with 300k population
Made me smile, I'm from outside a city we used to call "big city" when I was growing up, it had ~110K population and is the 9th largest in the country or something :P Anyways, that city still has night service, so not sure why a city with three times the population wouldn't, especially if it's a university city.
fragmede 3 hours ago [-]
If it's not able to support a robust bus system, it's not a city, just a really big town.
16 hours ago [-]
CodeCompost 1 hours ago [-]
Am I the only one here who thinks this is intrusive?
6 hours ago [-]
Cider9986 16 hours ago [-]
>WebSocket getrennt
Hug of death? Nothing loads.
calin2k 16 hours ago [-]
[dead]
Rendered at 12:41:20 GMT+0000 (Coordinated Universal Time) with Vercel.
Unfortunately there was no API with data on which intersections have traffic lights and I had to build these routes manually in Strava using satellite images.
I did learn in the process that some traffic light data is actually available from the government, but only for selected partners. The Flitsmeister app for example has it and shows at some traffic lights how long it will take for the light to turn green (in a car, not on a bicycle)
https://popupcity.net/insights/rotterdam-traffic-light-prior...
According to their presentation they are working on a rust firmware to do everything on the board.
It's important so that alternatives to Google Maps and Waze (Google) can emerge.
To create congestion data, one needs to own an OS with location tracking, or be an international mobile network. Won't happen.
[disclaimer : I work on an open source alternative to big tech's maps]
The risk of the data being invalid seems as risky as the privacy implications in this case.
When opening the map on Firefox/Linux zooming to like a France-size view and then not doing anything, the view keeps scrolling up and down relatively slowly, but very annoyingly.
Zooming all the way out, it looks like the globe is jiggling back and forth ever so slightly, but continually.
I've recently seen this happen on another mapping application ( cannot remember which one) so it's probably in down the stack somewhere in a library you are using.
[1] https://docs.mapbox.com/map-styles/standard/guides/
https://cartes.app/#13.13/47.06727/15.44801
And its Tilemaker profile to generate the tiles : https://codeberg.org/cartes/serveur/src/branch/master/tilema...
The concept is that there is this protocol called ITS-G5, which is a European profile of 802.11p. Vehicles and traffic infrastructure can transmit telemetry on 5 GHz. Other vehicles and traffic infrastructure can use it for situational awareness.
This website collects that data using local receivers and aggregates it onto a map, similar to what website like ADSB-Exchange do with ADS-B.
What is concerning is that vehicles appear to broadcast a MAC address. Does this mean that ITS-G5, 802.11p, and C-ITS could be used for persistent tracking?
Somewhat related: 'Your car’s tire sensors could be used to track you': https://networks.imdea.org/your-cars-tire-sensors-could-be-u...
https://www.rtl-sdr.com/exploring-the-privacy-risks-of-tire-...
In Graz, the city where the authors live, there are 165 of such signals planned.
https://media.ccc.de/v/glt26-688-c-its-mit-einem-esp32-ampel...
>To improve coverage, we need your support! We have built a board with *ESP32-C5* and *PoE* that allows you to capture *C-ITS* packages yourself, and provide us for our face-up card, or process it yourself.
Edit: found it, https://codeberg.org/opentrafficmap
My gut feeling is that this seems like one of those things likely to face a lot of backlash when it becomes widely known.
The only reason you would assume a site would be global is if your definition of "global" is "works in the US" & you never bother to check for support of other countries. I live in the anglosphere outside of the US & I encounter more than enough US-only web projects for that not be to a default assumption I hold.
Most sites are not global - it's very odd to assume they would be.
If I got the impression that it was like OSM, that would give me the impression that it is only as global as my contributions to it (which is what lead to OSM becoming global).
I don't get why there isn't even a stub repo for a mobile app to contribute with. Or am I just not finding it?
https://codeberg.org/opentrafficmap/its-g5-receiver: "Current ordering situation
(as of 2026-04-23)
After the talk on Grazer Linuxtage (media.ccc.de, youtube.com) we got many responses from people also wanting to buy this receiver. We fixed a few issues of the first revision and ordered 200pcs of Revision 2.
We expect the 200pcs to arrive in the first week of May, 2026. The cost of one complete receiver (excluding case and mechanical parts) is about 20 €.
If you want to purchase a receiver PCB, please contact us at the email liked in the Imprint/Impressum of opentrafficmap.org"
The authors of this project also shared that they intend on publishing more around this project. This seems to be mostly an early demo that was intended for the live event.
But I'll probably add my own receiver soon!
It's entirely reasonable to expect that a project with an extremely similar name would also work in most of the world, which just happens to include the USA.
Does Graz not have night bus service?
[1] https://www.verbundlinie.at/en/customer-service/arriving-in-...
Made me smile, I'm from outside a city we used to call "big city" when I was growing up, it had ~110K population and is the 9th largest in the country or something :P Anyways, that city still has night service, so not sure why a city with three times the population wouldn't, especially if it's a university city.
Hug of death? Nothing loads.