Bus contracts, like so many things in Hawaii, are complicated by the facts of island life.

On the list are the high costs of land for bus baseyards and the difficulty of expanding businesses statewide, transporting vehicles at great expense from one county to another.

There are 10 companies that bid on contracts for school bus service, but more than half do business on a single island.

In the context of soaring costs for contracts that recently have attracted little competitive bidding, contractors confirm being questioned by the FBI as part of a probe into whether companies colluded to keep prices high, an allegation company officials have denied.

Even without collusion, say state Department of Education officials, contractors can argue that they have little incentive to aggressively pursue competitive bidding, especially with some of the executives past retirement age.

The bottom line is that the price tag for providing the service has tripled in the last decade, to $75.5 million in fiscal year 2012. Whether or not the FBI can make the case for wrongdoing, the DOE should immediately begin reducing costs, even if it means some service on Oahu must be curtailed.

The Legislature recently heard a presentation by the DOE’s Student Transportation Services Branch, which is seeking the restoration of $42 million cut last session.

The Abercrombie administration wants the supplemental allotment to be only $25 million.

It would be sensible to find a compromise point, especially since a reliable municipal bus system exists as an alternative for the Honolulu school district, especially for middle-schoolers and older children.

Under existing policies, students in kindergarten through fifth grade qualify for bus service if they live more than a mile from school; older students must live at least 1.5 miles away to use the service.

In one of the mandatory services, the DOE must transport children in schools falling short of the federal No Child Left Behind marks, if their families opt for them to attend other schools.

But the most expensive per-capita mandate concerns special education students: Curb-to-curb transport costs $30.7 million statewide, serving 4,103 students.

A lot of leeway remains, however. DOE officials have come up with a roster of cost-cutting options, including increasing the qualifying distance, consolidating routes, increasing fares and eliminating free passes or at least cutting back on them.

Randy Moore, the DOE’s assistant superintendent for facilities and support services, said the problem dates back to about 2007 and although the then-elected school board was informed about it about two years ago, nothing was done.

Clearly something, likely the FBI inquiry, has jolted the contractors. The four contracts put out to bids last fall for the coming school year — routes in Central Oahu, Honolulu, East Hawaii and West Hawaii — drew three bids each.

Good. There may be any number of reasons that competitive bidding has slowed, but no reason at all that the DOE, which serves the taxpayer, should sit back helplessly and let costs find their own level.

The state simply can’t afford to do that.