(a) The commissioners court of a county, by order entered on the minutes of the court, may determine and set a maximum reasonable and prudent speed for a vehicle travelling on any segment of a county road, including a road or highway intersection, railroad grade crossing, curve, or hill.(b) In determining the maximum reasonable and prudent speed, the commissioners court shall consider all circumstances on the affected segment of the road, including the width and condition of the road surface and the usual traffic on the road.(c) The maximum reasonable and prudent speed set by the commissioners court under this section may be lower than the maximum speed set by law for a vehicle travelling on a public highway.(d) A speed limit set by the commissioners court under this section is effective when appropriate signs giving notice of the speed limit are installed on the affected segment of the county road. Acts 1995, 74th Leg., ch. 165, Sec. 1, eff. Sept. 1, 1995.