It is presumably lawful for the driver of a vehicle upon a highway [or upon private or public property open to public vehicular travel] to drive the vehicle at a speed not exceeding ______. Regardless of any posted speed limit, driving at a rate of speed that is unsafe is unlawful.
A person may not drive a vehicle upon a highway [or upon private or public property open to public vehicular travel] at a speed greater than the speed limit or greater than is reasonably safe and prudent under the conditions then existing, having regard to any actual and potential hazards. Conversely, a person may not drive a motor vehicle at such a slow speed as to impede the normal and reasonable movement of traffic.
[Every person must drive at a safe and appropriate speed while [approaching and crossing] [an intersection] [a railroad grade crossing] [going around a curve] [while approaching a hill area] [traveling upon any narrow or winding roadway] [special hazards exist with regard to pedestrians or other traffic or due to weather or highway conditions].]