A frequent route from Orange County CA to San Diego is through the Marine Base at Camp Pendleton. They will not let you aboard (their terminology) without a helmet and valid ID. The alternate is the I5 freeway shoulder for ten miles, or a fifty mile detour inland. Not a problem for me, as I choose to wear a helmet, and am not opposed to showing ID. There are Plenty of "rebels" who are opposed to one or the other, or often both. I see them on the freeway shoulder all the time. Good for them.