[humblegunner]

Well if she walked off with the keys, the passengers couldn’t take the bus anywhere. They could certainly escape, but then where would they go?

The same place the driver went, presumably.

The heroic stalwart driver seems to have been able to brave the wilds, why not the passengers?

There may have been a strip mall half a mile away, who knows.

[HiTech RedNeck]

Well we aren’t told where the driver went, but for all we know he/she/it called a bedfriend to come get him/her/it, or maybe even rented a car. A getaway for one is a little easier than a getaway for a busful.

[catnipman]

“The heroic stalwart driver seems to have been able to brave the wilds, why not the passengers?”

From your description of the driver, I see that you assumed she must have been an OWS protester and that she walked off and left the bus stranded as an act of solidarity with the progressive heroes of Zuccotti Park.