N.D. Cent. Code § 24-09-05
At each grade crossing where, because of the dangers attendant upon its use, the reasonable protection to life and property makes it necessary for all persons approaching the same to stop before crossing the railroad tracks thereat, stop signs shall be installed. The department, after performing an engineering study of the crossing, may designate any crossing requiring such additional protection as a stop crossing and shall notify the road authority with jurisdiction over the roadway of such designation and of the location where the stop sign is to be installed. Within thirty days after such notification, the road authority shall erect uniform stop signs on separate posts at the designated location on each side of said crossing.
N.D.C.C. § 24-09-05