"Perhaps most striking about San Francisco's casual carpooling is that it is completely unregulated and without official oversight-it is in no way affiliated with the local government or transit authorities. But they're certainly aware of it; the scale of casual carpool is enormous, and its impact is significant.
Despite their loss in revenue, MTC transit authorities regard the practice as positive. It eases transportation stresses, creates significant travel time savings, dramatically reduces traffic, and contributes to the 'more efficient use of an already established and trafficked infrastructure.' As Rentschler says, "The single largest transport resource not just in the Bay Area, but in the entire country, are the empty seats in everyone's car." This resource often simply goes to waste."