(a) Notwithstanding subdivision (1) of section 385 of the Vehicle and Traffic Law, vehicles used for selling frozen desserts may exceed the legal width limitation of 8 feet by up to 18 inches if the overage is caused solely by a caution arm which conforms to Part 69 of these regulations.

(b) Nothing in this Part shall be construed as allowing the body of a vehicle used for selling frozen desserts, excluding a caution arm, to exceed the width limit set by section 385 of the Vehicle and Traffic Law.