PARIS — On a recent Friday evening, Vincent Accart maneuvered his 20-year-old Mercedes station wagon through the rush-hour traffic to a rendezvous at a busy fuel station on the edge of Paris. There he met three strangers who hopped into his car for a three-and-a-half-hour drive to Rennes, in Brittany. It had all been arranged beforehand, via the Web.

For more than a year, Mr. Accart has been making the weekly commute to Paris, where he found new employment last year after losing a job closer to his home in Rennes. To amortize the cost of fuel and tolls — about €150, or $195, for a round trip — he fills the other seats in his car, using a French Web site that arranges shared rides.

“When my car is full, it covers 75 percent of the cost,” he said, adding that moving to Paris was not an option because of the prohibitive cost of housing his six-member family. “I’m not doing it to make money, just to be able to keep my job.”

One of the side effects of the European economic crisis is a surge in carpooling, as people from many walks of life seek to cut their outlays on travel. Workers making daily treks to and from the office, students heading home for the weekend and even vacationers chasing the sun are turning private vehicles into the newest form of public transportation. Rising environmental awareness may have fueled the trend.