What is the legal test for making permanent improvements to the surface of an easement on a private property?

The judgment decrees, "The Easement road surface shall remain unpaved." Appellant claims that he should be allowed to improve the easement "with an appropriate impermeable, permanent surface" to "ensure that the pathway is usable at all times, including in inclement weather." "The owner of a dominant estate may do that which is reasonably necessary to enjoy the easement and, as an incident thereto, keep it in repair and fit for use. [Citation.]" ( Scruby, supra, 37 Cal.App.4th at pp. 706-707, 43 Cal.Rptr.2d 810 ; see also Zimmerman v. Young (1946) 74 Cal.App.2d 623, 628, 169 P.2d 37 ["The right to use the property for road purposes carried with it a right to make necessary and reasonable improvements for the purpose for which it was intended to be used"].)