Streets and Highways Code § 187
ARTICLE 5. Funds for Highway and Public Mass Transit Guideway Purposes
For the purpose of allocating State funds available for highway purposes the counties of the State are placed in these two groups:
Group No. 1. All those counties not included in Group No. 2.
Group No. 2. The counties of San Luis Obispo, Kern, Mono, Tulare, Inyo, Santa Barbara, Ventura, Los Angeles, San Bernardino, Orange, Riverside, San Diego and Imperial.