The country is Wales. The subject is bicycle safety; something we can all agree, probably, is very important. The sign is meant to warn riders that there is construction ahead, and they should walk their bikes. Problem is, the sign is also translated into Welsh. And the Welsh words, translated to English, actually read:
'bladder disease has returned'
IC Wales.com had some fun with this, and we don't blame them. As for us, we tried our damnedest to come up with a Floyd Landis joke here, but nothing much came of it. Sorry.
Road Sign Leaves Welsh-Speakers Bewildered [IC Wales.com]
(UPDATE: The Welsh seem to have a lot of trouble with this sort of thing.)