The Department of Transportation may at its discretion require permits for advertising signs, displays, or devices which are placed or allowed to exist along or upon the Highway Beautification Control System or which are at any point visible from the main-traveled way of the Highway Beautification Control System, except for on-premise signs, displays, and devices, as defined in the department's rules and regulations, for advertising activities conducted on the property on which the sign, display, or device is located. Such permits shall be renewed biennially. Each sign shall bear on the side facing the highway the permit number in a readily observable place for inspection purposes from the highway right-of-way. The department shall adopt and promulgate rules and regulations to implement and administer sections 39-212 to 39-226. The department may revoke the permit for noncompliance reasons and remove the sign if, after thirty days' notification to the sign owner, the sign remains in noncompliance. Printed sale bills not exceeding two hundred sixteen square inches in size shall not require a permit if otherwise conforming.