I don't know the exact "cost", which may be too complicated to calculate it, including car,maintenance,gas,insurrance, even tickets.... 7 f$ A' F ~# v, w% X d# L' a% V4 d2 O# Z
For me, I think car-pool is just to share part of gas "cost" and have some fun on road..... 0 V% o+ y7 T4 g2 J' V2 v4 y" s' N$ K. I$ A p( m5 [) m
I usally charge passager 30 bucks for a trip.