R.I. Gen. Laws § 45-6.1-1: Mail payment of penalty for non-moving traffic violation.

Notwithstanding the provisions of any general or special act, any ordinance adopted by any of the several cities or towns (whether adopted prior to or subsequent to the passage of this chapter) providing for the regulations of the parking of motor vehicles upon the public highways, shall permit the payment of any fine imposed for violation of the ordinance by mail. Any ordinance which fails to comply with the provisions of this chapter is null and void.