Cal. Streets and Highways Code § 220

In designing safety roadside rests, the department shall design only those safety roadside rests which are reasonably economical and which will provide the motorist a place where he may stop for a short time during daytime and nighttime hours. The Legislature recognizes that the size of such safety roadside rests, together with the facilities therein, will differ according to location and potential use. Such safety roadside rests may contain, among other things, depending upon the size and use thereof, parking places for vehicles, picnic tables, sanitary facilities, telephones, water, landscaping, tourist information panels, traveler service information facilities, and facilities for the distribution of current news. Such safety roadside rests shall not contain camping or recreational facilities. The safety roadside rests located on that portion of Route 5 in the Sacramento-San Joaquin Delta area may also contain displays and examples of California agriculture.