ATLANTA (AP) -- Most weekday afternoons, Patricia Israel waits in her front yard for the school bus to drop off her 6-year-old twin sons.
The boys beg to ride the bus every day, which Israel said is fine with her. She sees it as environmentally sound transportation that reduces traffic on the streets and at the school.
It also saves money on gas for her sport utility vehicle. "We're looking at getting a hybrid," Israel said. "Every time I fill up the gas tank, it's like $75."
With gas prices hovering around $3 per gallon, more parents are sending their kids to school on the bus this fall, and school districts across the nation have noticed the increase in ridership.
"The more the prices go up, the less riders get to school on their own and they go with our buses," said Doug Geller, assistant director of transportation for the Clark County School District in Las Vegas.
In Las Vegas, ridership has risen to about 45 percent of the district's more than 320,000 students. The system opens an average of 10 new schools a year, sprinkling bus stops throughout the surrounding neighborhoods, Geller said.
In the fast-growing Phoenix suburbs, bus ridership is skyrocketing as districts grow by thousands of students each year. Gas prices help attract riders, but heavy road construction and new air-conditioning in buses have also contributed to the increase, said Dianne Bowers with Gilbert Public Schools, southeast of Phoenix.
Some schools are doing more to encourage bus riders.
Janette Shealy, a teacher in the fast-growing Atlanta suburb of Alpharetta, Ga., said her school sends letters to parents about the environmental advantages of the bus system and sponsors a "bus ridership week" each semester when bus riders get candy and prizes.
"We try to just create an awareness of the fact that car vapors impact the quality of our air -- the fewer vehicles on the road the better," Shealy said. "Plus, you're never tardy when you ride the bus."
At the Atlanta school where Israel's twins attend, Principal Sidney Baker said he has noticed fewer cars waiting outside the school in the afternoon since classes started last week. He said he encourages parents to put their children on the bus because it eases traffic congestion and makes the school grounds safer during the morning drop-off and afternoon pick-up times.
While gas prices play into some parents' decisions, most are swayed by "a lot more important reasons," said Lisa Malice, education chairwoman for the Georgia PTA. Some drive their children to school to spare them a long bus ride.
"One parent told me she likes to spend a little extra time with her kids in the morning," Malice said. "When the bus is picking them up 50 minutes before school starts and dropping off half an hour before school starts, it doesn't make much sense for the kids to get up that early."
Many parents simply like the convenience of not having to fight traffic, especially parents who work far from their child's school.
"Gas really is so expensive," said Mary Lynn Jones, a stay-at-home mom who has four of her five children riding the bus to an elementary school in northern Atlanta. "It's just so much easier."