(a) No permittee shall locate or maintain any bench at a point less than 18 inches or more than 30 inches from the face of the curb, and each bench must be kept parallel with the curb.
(b) No bench shall be more than 42 inches high nor more than 2 feet, 6 inches wide, nor more than 7 feet long, over all.
(c) Each bench must have displayed thereon, in a conspicuous place, the name of the permittee and the permit number.
(d) It shall be the duty of the permittee to maintain each bench at all times in a safe condition an at its proper and lawful location, and to inspect each bench periodically.