Radio program with public transport focus by country

I know of no such radio station and I suspect that at least in Germany they will be scarce and scattered if they exist at all.

From a historical point of view, radios were stationary in your home except for the one that you had in your car. There is an incentive for both sides — the police offering the (road) traffic data and the station broadcasting it — to include information on the road delays. The radio station can bind listeners to it if they give the impression of providing fast and complete coverage. On the other hand, the police gets a channel for public announcements they can use for e.g. wrong-side driver warnings.

No such benefit generally existed for railways or local public transport. Most importantly, most people would not have a radio with them on a bus or train.^[1] And the public transport or railway companies typically don’t need to warn many people at once — if they do, they have speaker systems in place. Thus, no both-sided interest existed.

Nowadays, many transport associations and railway companies have introduced app services that tell you if things happen that could affect your journey. These are typically updated more or less in real time while a radio station would have to set aside a slot in their programm, which is typically only once every half-hour. So any radio-based solution is doomed to be slower and thus less helpful.

Of course, I could be prove wrong. If I listen to radio programs, it is the traditional radio wave-based stations. The internet may well have introduced a lot more that I am not aware of.

Note:

[1]: Of course, portable radios exist and some ICE generations also had radio programs that you could listen to with headphones at your seat. But these were more the exception than the rule: a few years ago people wearing headphones in the street were rare.

It is not radio but this is the best sample, and most reliable repeated, I know.
When you watch BBC 1 breakfast, on the London version of the TV channel, you will see updates on how the underground runs.
They show the same screen as you find on entering the underground stations.
If there are huge delays on bus lines and the trains, they will also mention that. They do also mention main road blockages, but not as annoying as the every 30 minutes updates on the radio.

I have heard some train delays mentioned on the Dutch radio, likely Radio 2, but it can also have been 3 FM, and in special circumstances all Dutch radio stations will mention it. That is when there is a whole region of the country affected, or when the airport can not be reached by train.
Most of the time the trains are not mentioned unless the delays are big, not even on the best channel for it.

Even with this service, the car traffic information will take 10 times as much time. (And most of those delays are regular ones, which are there almost every day, so do not need every 30 minutes repeats.)