BOSTON (CBS) – AAA now expects the average gas price in Massachusetts to hit $4 this week.

Jackie in Amesbury is Curious:

“With gas prices rising every day, why don’t we hear more about car pooling?”

Carpooling is actually in vogue again, and you can save a lot.

WBZ-TV’s David Wade reports.

Carpooling has been around for decades, but for Catherine and Christine, it’s financially fashionable.

“About $500 a month now that I’ve been carpooling and switched vehicles,” said Catherine.

In her new hybrid, the co-workers come into Cambridge from southern New Hampshire.

“I save a little over $300 a month now,” said “I mean that’s a car payment. For my financial situation that’s awesome,” said Christine.

AAA said last year, when gas was a buck cheaper it cost an average of 58 cents per mile to drive. That includes gas and maintenance. In that case, if you drive 12,000 miles a year, it will cost you about $7,000. But, if you carpool and only drive half the time, you could save about $3,000.

The prospect of saving has people hitting websites like Craigslist. In one ad, someone looking to carpool from Peabody to Boston promises not to be “overly chatty.”

“We are starting to see a bigger use of HOV lane, which indicates more people are carpooling,” said Acting highway administrator Frank DiPaola.

DiPaola. thinks “Mass Ride,” a state-funded organization is helping to convince people. Its website even offers rewards to people who carpool.

“I think sometimes the social interaction in a carpool is just as interesting as having your own space or listening to your radio or texting someone, which we’re not supposed to be doing,” said DiPaola.

Just make sure you pick the right person to carpool with. You may end up spending more time with that person than you do with your spouse.