Van pool phone lines are flooded. Bus ridership is up. Even good, old-fashioned walking is finding new enthusiasts.

Apparently, Hawai'i drivers do have a tipping point: $3 per gallon.

After years of touting alternative transportation without much success, officials say an increasing number of Hawai'i drivers may finally be ready to give up their private vehicles.

"I figure I'm saving about at least $200 a month in gas alone," said Malcolm Chun, a Hawai'i Air National Guard mechanic who formed a van pool with fellow workers in July, when gas prices started going through the roof.

Chun is just one of thousands of residents who are questioning and rethinking their driving habits now that the average price of gasoline appears ready to reach $3.50 a gallon.

In the past, transportation officials said, Hawai'i vehicle owners may have adjusted their driving habits somewhat to cope with the rising cost of gasoline but were reluctant to give up their automobiles entirely. Though the numbers are still comparatively small, there are indications that some of those drivers are starting to reach their auto cost limit, officials said.

"In the past we would get a good 20 to 25 calls a day. Now, we're getting anywhere from 50 to 60 a day," said Vicki Harris, head of Van Pool Hawai'i, a state-financed organization that provides subsidized vans for drivers who organize car pools from their neighborhoods.

"We don't have a real natural car-pooling constituency in Hawai'i, but I think with the price of gasoline now the idea is really starting to hit home," Harris said.

Bus ridership also is up, although it's not clear how much of that is attributable to gas prices.

For the first few days of September, ridership has averaged about 220,000 per day, about a 6 percent increase over a year ago, said James Burke, acting chief of the city's Public Transit Division. But that's still fewer than the 225,000 to 230,000 daily riders who used the bus before a crippling strike and an increase in fares two years ago.

"The numbers are going up, but it's too early to tell how much of that is because of gas prices," Burke said. The increase could also be the result of a new university bus pass started this year or because of people who are just now returning to the bus system after the strike, he said.

There's no doubt, however, that the gas price increases are hitting Hawai'i residents in the wallet.

The national Environmental Working Group estimates that at $3 per gallon, the average Hawai'i two-car household will end up paying $270 more per year in fuel costs than they would at $2.61 a gallon. That would add up to more than $77 million for O'ahu.

If the cost of gas jumped to $3.50 and stayed there for a year, the extra cost would come to $617 per household, or about $177 million for O'ahu, the group says.

Chun, who lives in Mililani and works at Hickam Air Force Base, took a look at his own numbers a few months ago and decided he couldn't pass up the opportunity to form a van pool.

Under the state program, each person in the van pool pays $55 per month and a share of gas and parking costs. In return, the state provides a new van that can easily accommodate seven people. The program also pays for all insurance, maintenance and other operating costs.

Despite the problems in accommodating six other riders, Chun says the program is a big money saver, especially when you consider the extra money he doesn't have to pay on car payments, insurance, wear and tear, and maintenance on his own car.

"You have to make some shifts in your time management," said Chun, who leaves his home at 4:50 every morning and spends about 30 minutes picking up the other riders before heading to work. "But then you realize that each person in the van is probably saving about $200 a month."

Harris said the decade-old van pool program runs about 170 such van pools statewide and has enough money for another 150.

"All of a sudden your average working Joe is finding that it makes more sense to try this instead of just burning up the money in his car and ending up with nothing to show for it," she said.

Hundreds of people also lined up yesterday at a downtown health fair to learn more about the oldest form of transportation: walking.

"I hope some of them are thinking about giving up their car," said Steve McCall, a health education specialist.

"This is the time to start thinking about kicking the kids out of the SUV and letting them walk to school," said McCall, who uses a bicycle for his daily 11-mile commute to work. "They would not only save money, but they'd get the health benefits of walking, too."

However, tour bus driver Cowboy Kahunanui didn't think the rising prices and the number of people switching to alternative transportation would make much of a dent in the traffic he encounters on the road every day.

"I doubt it," he said. "A lot of people just don't want to car-pool or ride the bus. Traffic has gotten a lot worse in the last three or four years and there's just no respect out there."

Reach Mike Leidemann at mleidemann@honoluluadvertiser.com.