School administrators are spinning their wheels trying to cope with the soaring costs of fuel for school buses. The bottom line: More students will walk farther this fall.

"All the less drastic measures have pretty much been exploited," says Robin Leeds of the National School Transportation Association. "All that sort of easy-picking fruit has been picked."

Fuel costs are up 35%-40% since last year. Schools are making more students walk to school and axing buses for extracurricular activities, and more operate on four-day weeks:

• Garden City, Mich., schools have eliminated Saturday transportation for extracurricular activities. Last year, the district cut out daily buses for high school students, but after two weeks, the buses were back when parents expressed safety concerns.

• In Nash-Rocky Mount public schools in Nashville, N.C., a bus for any extracurricular event that is not a competition now depends on funds raised by students or booster groups.

• The Montgomery County, Md., school board has given Superintendent Jerry Weast authority to expand how far students will walk to school or a bus stop if gas prices create "exigent circumstances."

At least 86 school districts are on four-day weeks, according to the National School Boards Association. Kentucky's Webster County schools switched to four-day weeks in 2005, saving the district more than $400,000 so far.

For the coming year, the school board is considering busing only students who live more than a mile from school rather than let everyone ride, Superintendent James Kemp says. Transportation for sports and other activities will be up to parents.

In Ohio, more schools are cutting back to the minimum requirement, which means buses only for kindergartners through eighth-graders who live more than 2 miles from school, according to Pete Japikse, the state's director of pupil transportation. The number of students on daily buses is down from 1.1 million to 1 million.

Busing advocates say cutting basic bus service jeopardizes safety. About 800 students die each year going to and from school, but only about 20 deaths are bus-related, according to the National Academies of Sciences.

"Every time you make more kids get off the bus and go some other way, you're increasing the risks that those kids are not going to get to school alive," Leeds says.

Drastic cuts also threaten attendance, says Mike Martin of the American School Bus Council.

"When you start to cut transportation, you eliminate the ability to participate in a lot of things that most kids take to be the most enjoyable parts of school," Martin says. Some students forced to find their own way to school may not go at all, he says.

Contributing: Rebecca Kaplan and Greg Toppo