Navigating the Casual Carpool

Casual carpool, a cross between hitchhiking and carpooling, has been moving Bay Area commuters since the 1970s. The phenomenon, which is particularly popular in the East Bay, has no official rules or guidebook, so passengers and drivers negotiate things like radio stations and bridge tolls among themselves. What are your expectations for drivers and passengers when you use the casual carpool? What “only in casual carpool” experiences have you had?