The regulation of advertising displays adjacent to any interstate highway or primary highway as provided in Section 5405 is hereby declared to be necessary to promote the public safety, health, welfare, convenience and enjoyment of public travel, to protect the public investment in such highways, to preserve the scenic beauty of lands bordering on such highways, and to insure that information in the specific interest of the traveling public is presented safely and effectively, recognizing that a reasonable freedom to advertise is necessary to attain such objectives. The Legislature finds: