It’s easy to see how Ms. Dickinson is violating purpose of carpooling (taking cars off the road), but in this study Bob Poole and I make the case for ditching the carpool lane concept entirely. It just doesn’t work very well because most carpools don’t take cars off the road. Usually they’re “fampools” because they consist of family members who would be going the same way anyhow.
Even if we forget the fampool thing, carpooling still doesn’t work well because it’s practiced most when it’s needed least. When would we want carpooling to be most common? During the morning and afternoon commute, after all, that’s when gridlock’s at its worst. But average occupancy rates are low during these periods. On weekdays they’re at their highest after 7pm and occupancy rates are higher still on weekends. More on Ms. Dickinson’s run-in with the law here.