What does a ‘Slippery road surface’ sign mean to you? Apart from the obvious, it can also mean that the road surface ahead may have a different level of grip to the one you are currently driving on, which means it isn’t slippery as such – just different. However, if you come across one of these signs put up as a temporary sign (like roadworks) it means something totally different. It suggests there has been a spillage on the road ahead, such as oil or mud, making conditions slippery. Remember, signs are always there for a reason.