Basic speed rule
The “basic speed rule” as it is often referred, exists in *all states. By definition “no person shall drive a vehicle at a speed greater than is reasonable and prudent under the conditions, including actual and potential hazards then existing.” (UVC 11-801-Basic Rule). Think of the basic rule as the trump card of all posted speed limits. If weather, road or traffic conditions merit slower speed then the posted speed limit is no longer the legal speed limit. Rather, the basic rule or what a prudent and reasonable driver would travel under said conditions.
*Tennessee does not have a basic speed rule.