R.I. Gen. Laws § 31-24-53
No person engaged as an itinerant vendor of food items from a motor vehicle operated, or caused to be operated by him or her, upon the public streets or highways of the state of Rhode Island, shall operate the motor vehicle or cause the motor vehicle to be operated for the purpose of vending food items upon the city streets or highways unless the motor vehicle shall have been equipped with two (2) flashing lights, one yellow located on the front bumper and one red on the rear bumper of it, except those vehicles which have flashing warning lights as standard equipment. When the motor vehicle shall have been stopped for the purpose of the intended itinerary business, they shall continue flashing as a warning of its position to all approaching vehicular traffic. Violations of this section are subject to fines enumerated in § 31-41.1-4.
R.I. Gen. Laws § 31-24-53