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. 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.
: 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.