Utah Code Ann. § 41-6a-902
(2)
(a) Except when directed to proceed by a peace officer, every operator of a vehicle approaching a stop sign shall stop:
(3)
(a) The operator of a vehicle approaching a yield sign shall:
(b)
(4)
(a) A collision is prima facie evidence of an operator's failure to yield the right-of-way after passing a yield sign without stopping if the operator is involved in a collision: