An easement by necessity arises when land is divided in such a way that a portion of it is left without access to a public road or utility. The essential components for such an easement include previous unity of ownership, wherein the dominant and servient estates were once part of a single larger property; a clear necessity of the easement for the beneficial use or enjoyment of the dominant estate at the time of severance; and the lack of an alternative reasonable access route.
For example: If a farmer sells a piece of landlocked agricultural land that has no other path to a public road except through another part of their original property, this could constitute an easement by necessity.