UPDATE: Look what I found in the CA Streets and Highway Code, section 731:

Selling on Right of Way Prohibited: S&HC 731
It is a misdemeanor to park a vehicle or structure on the right of way for the purposes of selling the vehicle or structure, or to sell items carried within a vehicle or structure.
Vehicles or structures placed on the right of way for the purpose of selling them are a public nuisance. Caltrans shall remove them from the highway.
Vendors may take orders and deliver items from a vehicle on the State highway immediately adjacent to the premises of the purchaser.

I hope he made LOTS of money, otherwise, with the ticket or the arrest the MCSO is on its way to give him, this is not very cost effective. Do NOT try this yourself. Locals are fed up and reporting all violators. Photo by Diane Allen: