Well, I always tried to consolidate errands to save both money and time. As far as how much it costs...I try not to look. Lucky for me right now my distance to work is not bad, and I avoid peak rush hour. I am in the Orlando, Fl. area and our only mass transit is busses and they don't run often enough(where I am)to help me out.
The people in this county voted down light rail and the Governor manage to get the State Rail voted for by the voters killed (by another vote after doing nothing for 2 years).