The reason I ask is because of a post I read by Atomic Floozie entitled "How to play NHC:PI. Excellent play-by play. I've read it twice and, now that I have started my own NHC:PI campaign, I refer back to it frequently. During one part of her write-up, she references a large number of travel encounters on the City Transit and says [and I'm paraphrasing] - Pearl is beginning to wish she'd taken her own vehicle - instead of the train.
That makes sense. You are on the train with a lot of other people. Hence the chance of an encounter. In your personal vehicle, you are usually alone or with someone you know. The chance of a travel encounter would seem to be pretty remote.
Of course, someone could always approach your vehicle at a stop light and attempt to rob/carjack you, but the chances of that happening wouldn't be the same as the chances of an encounter on a train full of strangers.
a Confrontation could result in a car chase! That would be cool, but with no vehicle rules, how would that play out? Chillin'? I suppose could be done in a car [if you had a passenger or two] or you could stop along the way in a given area.