I don't know the exact "cost", which may be too complicated to calculate it, including car,maintenance,gas,insurrance, even tickets.... # g* o* T1 |1 S# l6 c% K# R7 Q+ ?- i; b* ?
For me, I think car-pool is just to share part of gas "cost" and have some fun on road..... , Z. u. `9 P: X( W' |+ _& J4 t e6 W) N) N6 }, ^; o5 X
I usally charge passager 30 bucks for a trip.