I don't know the exact "cost", which may be too complicated to calculate it, including car,maintenance,gas,insurrance, even tickets.... ; R( a4 ]/ f/ O* O4 O# T0 a& L# B. b4 i9 g1 S- ]4 S
For me, I think car-pool is just to share part of gas "cost" and have some fun on road..... ) g% `: r* n* u) g4 Z# U. o8 `7 T7 X: u1 \
I usally charge passager 30 bucks for a trip.