Four people carpooling - of course that is cheaper. Cut that down to just two people and the price difference would be much closer and each couple would need to do their own math. My point was that those parking lots that John Riecke dislikes so much are what gets the cars off the highways. People leave the cars out in the suburbs instead of bringing them into the urban center. Cost savings or not for the commuter, that is the whole point of mass transit.