Says the proposal is abandoned in 2011. The thing is OSM does not deal with real time data, the general rule is if the data is likely to change within the next month it doesn't go in OSM. A lot of OSM apps and servers cache the OSM dataset so anything like a road closed for one day would be stale before it even reached users.
Thats one of the big issues with OSM though, they have an attitude of "Thats not my problem, it should go in another dataset" but then no one actually has an alternative place to put it so users just miss out.
There are people working on layering the data better. I was at a talk about this at two State of the Map conferences. I don't have links or names ready, on mobile, sorry.
The idea, in my words, is to have a standard on how to link between layers: how to merge them, so to say.
That way, a routing app for a car would only need the roads and their features layers. But the search engine for tourists needs the poi layer and not all the road details.
A 'live' layer for e.g. traffic density could then be a neat commercial product for OSM consumers. But without standards to link your layer to, say, the OSM streets, it is almost impossible to offer and process such a layer.
Thats one of the big issues with OSM though, they have an attitude of "Thats not my problem, it should go in another dataset" but then no one actually has an alternative place to put it so users just miss out.