Burdened with a fleet of buses whose fuel mileage is measured in single digits, school districts are looking for ways to shave the miles they drive.

Every time diesel increases a penny it costs taxpayers another $100,000 in fuel for Washington’s public school buses, said Allan Jones, director of pupil transportation at the state Office of the Superintendent of Public Instruction. A one-dime increase means an extra $1 million.

So what’s happened since the start of last school year has districts reeling – an increase of nearly 17 dimes, from an average of $2.97 a gallon last September to $4.66 this week, according to federal statistics. In response, about a third of U.S. school districts are consolidating or eliminating bus routes, the American Association of School Administrators reports.

Inland Northwest schools are taking a variety of small steps.

Jill Hill, transportation director for the Coeur d’Alene School District, has scrutinized every route, cutting a total of 175 miles a day. That should save her district 4,000 gallons of diesel in the upcoming school year.

“You might save one mile on one route. You might save five miles on another route” without making kids walk significantly farther, Hill said.

She also eliminated 75 percent of left turns that require crossing oncoming lanes. That’s a step that’s gotten a lot of talk in schools, ever since United Parcel Service announced it’s saving 3 million gallons a year by virtually eliminating left turns on routes.

Mead School District is cutting back on field trips, said Jack Lewis, district director of transportation.

Mead buses travel more than 5,000 miles a day in the sprawling district, and while Lewis is finding some ways to make routes more efficient – he reviews them every summer – there’s only so much that can be done without making some kids spend an inordinate amount of time on the bus.

“Anytime we get more than an hour (each direction) we have to take a look and try to mitigate that,” Lewis said.

East Valley School District is midway through a three-year process of eliminating bus stops within a one-mile radius of schools – those for which the state provides no funding. West Valley and Central Valley have invested in software designed to help plan more efficient routes.

“What we were able to do this summer is really analyze where our kids live and redo our routes, versus just running the same routes like we’ve done in the past,” said West Valley transportation director Brian Liberg.

Some children who live close to Ness Elementary School will no longer ride the bus, Liberg said. And a route that served the Bigelow Gulch area at the district’s northern edge will be eliminated, with other routes extended to serve those students. In addition to the fuel savings, the changes mean West Valley won’t be replace two bus drivers who retired.

None of the large Inland Northwest districts plans anything as drastic as moving to a four-day week, which the American Association of School Administrators says is under consideration by one in seven districts nationwide. Tiny Lyle School District in south-central Washington is seeking state permission to take that step, assuming residents also approve.

“It looks like there’d have to be legislation” allowing schools to make up for fewer days by lengthening the number of classroom hours, Jones said.

The biggest relief to Washington districts could come from other legislation, designed to change the way the state calculates payments to districts for busing students to and from school (field trips, and travel for sporting events or other extra-curricular activities, are a financial burden districts bear alone). The current system has been used since the early 1980s.

The state pays based on a formula that assumes a child should have bus service if the walk is more than a mile – calculated as the crow flies, without regard to the lay of the land.

So, for instance, there’s no reimbursement to the Wenatchee School District for transporting kids who live in a hilltop subdivision that’s less than a mile from school by air – but 11 miles by road, Jones said. Nor are districts reimbursed for offering rides for close-to-school kids who would have to cross dangerously busy streets.

An audit ordered by the Washington Legislature concluded that the state had shortchanged schools about $100 million for transportation in the 2004-05 school year alone. Diesel cost less than $3 a gallon back then.

But even the current system, based on the rate of inflation, in recent years has lagged far behind fuel increases. That’s meant a nearly $50 million shortfall over of the past five years.