I'm a bit confused by your question zara. Road signs are usually only covered when they have not yet come into force or are temporarily suspended (eg for roadworks). Of course, this would only affect regulatory signs (speed limits etc). The 'Think Bike' signs are non regulatory and are only there for information and to draw the attention of car drivers to bikes, as well as for the bikers themselves. In this case, I cannot understand why any official body (council/Police) would cover the signs. Do you think it is some local who is peed off with all the bikers in the area covering them up or what? By all means contact the Highways Dept, but I can't understand why they would cover the signs...or have I got the situation wrong?