California Code, Vehicle Code - VEH § 527

(a) “Road” means any existing vehicle route established before January 1, 1979, with significant evidence of prior regular travel by vehicles subject to registration pursuant to Article 1 (commencing with Section 4000) of Chapter 1 of Division 3; provided, that “road” does not mean any route traversed exclusively by bicycles as defined in Section 39001, motorcycles as defined in Section 400, motor-driven cycles as defined in Section 405, or off-highway motor vehicles as defined in Section 38012.

(b) Even though nature may alter or eliminate portions of an existing vehicle route, the route shall still be considered a road where there is evidence of periodic use.

(c) A vehicle route need not necessarily be a publicly or privately maintained surface to be a road, as defined, for purposes of this section. Nothing contained herein shall pertain to any property in an incorporated area or properties held in private ownership.

(d) This section is definitional only and nothing contained herein shall be deemed to affect, alter, create, or destroy any right, title, or interest in real property, including, but not limited to, any permit, license, or easement; nor shall this chapter be deemed to affect the liability, or lack thereof, of any owner of an interest of real property based upon the use, possession, or ownership of such interest in real property or the entry upon such property by any person.

(e) This section shall only apply in a county where the board of supervisors has adopted a resolution or enacted an ordinance providing for such application.