From WalletPop.com:
Everyone knows that carpooling can save energy and it diminishes traffic. When many people use only one vehicle to get to the same place, fewer resources are used up. But does the money it saves passengers really make much of a difference to your pocketbook?
According to the AAA, the average American one-way commute to work is 16 miles, so most of us travel an average of 32 miles a day just to get to and from our jobs. Using the commute computer at RideFinders.com, a ride-sharing portal, we found a savings of more than 50% for people in car pools.
Assuming a vehicle costs 59¢ a mile to operate five days a week (a typical figure under stop-and-go conditions over 15,000 miles a year), we can do a little math and find that when split equally among all members of the car pool, the per-person price for fuel, car maintenance, paring and tolls plunges by half or more compared to solo commuting.
That car will cost about $4,680 a year to get to and from work. Start splitting that among passengers, and the per-person cost plummets. For two people, the per-passenger savings is $2,340 per year. Split between three people, the per-person savings is $3,120 per year; instead of shouldering the whole $4,680 cost, each person in a three-person pool pays only $1,560.