No signs stating or relating to the price of motor fuel and no signs designed or calculated to cause the public to believe that they state or relate to the price of motor fuel other than the signs referred to in § 31-37-11 and required to be displayed upon pumps and other dispensing devices, shall be posted or displayed on or about the premises where motor fuel is sold at retail and within view of any public highway or reservation.
R.I. Gen. Laws § 31-37-12