2016 California Standards for Accessible Design Pocket Guide - Eff. Jan. 1, 2017

11B-503.3.3 Marking.

Access aisles shall be marked with a painted borderline around their perimeter. The area within the borderlines shall be marked with hatched lines a maximum of 36 inches (914 mm) on center in a color contrasting with that of the aisle surface.

[2010 ADAS] 503.3.3 Marking.  Access aisles shall be marked so as to discourage parking in them.