Speed limits may seem fairly straightforward: if you get caught driving over the posted limit, you receive a ticket. Indeed, this is the way that speed limit enforcement in Virginia usually works. According to FindLaw, the term for this type of speed limit is an absolute speed limit. However, it is only one of three different types of speed limits enforced within the United States.
Another type is a basic speed limit. The theory behind basic speed law is that a velocity that is unsafe under certain hazardous conditions is a violation even if it is below the posted speed limits. For example, a law enforcement officer may deem that your speed is too fast for the current conditions and ticket you if the roads are slippery due to weather conditions of rain, snow or ice.