(1) A person operating or driving a vehicle upon ways of this state open to the public shall drive it in a careful and prudent manner that does not unduly or unreasonably endanger the life, limb, property, or other rights of a person using the ways of this state open to the public. (2) A person who is convicted of the offense of careless driving is subject to the penalties provided in 61-8-711 or 61-8-716.
Careless Driving
Mont. Code Ann. § 61-8-302, under Vehicle Operating Requirements.
Mont. Code Ann. § 61-8-302