What is indicated by signs marking a private road?

The correct answer highlights that traffic regulations need not be followed on private roads unless specific permission is granted. Private roads are owned by individuals or organizations rather than by the public. Therefore, the owners have the authority to set their own rules regarding access and traffic regulation. This means that while some traffic regulations may apply, they can supersede general traffic laws based on the owner's discretion.

On private roads, the owners might establish particular conditions for their use, such as allowing only certain vehicles, limiting access to certain times, or imposing other restrictions that would not exist on public roads. Since these roads are not governed by the same laws as public highways, adherence to the typical traffic regulations is conditional upon the permissions granted by the road owner.

The other options incorrectly imply that private roads operate under standard public road regulations or that they are universally accessible. If one were to choose those options, they would misunderstand the nature of private roads and overlook the specific control that owners have over the use and traffic management of those roads.