Utah Code § 41-6a-1705: Obstruction to driver's view or driving mechanism.

(1) A person may not operate a vehicle when it is loaded or when there are in the front seat more than three persons that:

(a) obstruct the view of the operator to the front or sides of the vehicle;

(b) interfere with the operator's control over the driving mechanism of the vehicle.

(2) A passenger in a vehicle may not ride in a position that interferes with the operator's:

(a) view ahead or to the sides; or

(b) control over the driving mechanism of the vehicle.