For dozens of years, there has been an informal code of conduct for casual carpooling: A driver stops, picks up two people — one who sits in the front, the other in the back — and drives across the Bay Bridge. Usually, the radio is turned to an NPR station.

But today’s advent of a $2.50 charge for carpools is going to upset all the old rules. Will drivers ask for money for the toll? Will passengers be willing to pay? Will more people drive their own cars?  So much is up into the air.

Queena Kim, the community editor for The Bay Citizen, went to the North Berkeley Bart station this morning to see what people were thinking. The responses may surprise you.

Frances Dinkelspiel, Berkeleyside and CItyside co-founder, is a journalist and author. Her first book, Towers of Gold: How One Jewish Immigrant Named Isaias Hellman Created California, published in November...