No person under 14 years of age in the case of a snowmobile, or under 12 years of age in the case of an A.T.V., shall operate on streets or the roadway surface of highways or make a direct crossing of a trunk, county state-aid, county highway, or city street as the operator of a snowmobile or A.T.V. A person 14 years of age or older, but less than 18 years of age, may operate a snowmobile on streets and highways as permitted under this section and make a direct crossing of the streets and highways only if he or she has in his or her immediate possession a valid snowmobile safety certificate issued by the Commissioner as provided by M.S. § 84.872, as it may be amended from time to time. A person 12 years of age or older, but less than 18 years of age, may make a direct crossing of streets and highways as provided herein only if he or she has in his or her immediate possession a valid A.T.V. safety certificate issued by the Commissioner as provided by M.S. § 84.9256, as it may be amended from time to time.