On the subject of wet runways we can take it one stage further and talk about snow covered runways (winter is coming ). As a recent article in CHIRP illustrated ( it was just undernath the one about low cost carriers that caused all the furore ).
In some ways the situation is reversed in that, if I, as a controller have been given braking action figures from a runway inspection vehicle in conditions of wet snow ( we don't get anything else ), that indicate the runway braking action is extremely poor, I am not allowed to pass this information to aircraft. We used to be allowed to pass these figures as long as we added the suffix that they were unreliable.
So we are left in the situation as controllers in a fairly wintery outpost that if we suspect that the next landing 757 may go sailing off the end of the short runway, that we try and drop hints or desperatly search for other reports to put pilots off attempting landing. I am even awre of a colleague who contrived to send a landing medium sized jet, on short final, around so the flight crew could get a close view of the runway surface. The aircraft elected to divert.
I am aware that these problems are due to liability issues with mu-meters, BAA and so on. I am also aware that it has been raised at the UK flight safety committee. However so far nothing has been done.
...and winter is almost here...
