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]
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 o…
I commute using one of the several paths and there's only a coarse relationship between the times and paths congestion, but there's absolutely no certainty regarding the actual congestion. Single broken down vehicle on the single lane road can cause backpressure to the key places and make non-obvious variants MUCH better.
As a result I always drive/ride with Waze (I know! ) and I'd love some alternative. Google maps is too slow.