Montana officials say federal highway spending will cover less than a third of the state's $15.8 billion in transportation needs over the next decade.

Yet there are no immediate plans to add significantly more state money into the mix or make other broad changes to cover the anticipated shortfall.

Other states have turned to alternatives such as toll roads to supplement their federal cash.

Montana Department of Transportation Director Mike Tooley says that's not feasible in Montana because of its low population density.

Federal spending pays for the overwhelming majority of highway construction in Montana. It declined 2.3 percent in the state over the past five years on an inflation-adjusted basis.

Tooley says roads could start to deteriorate if spending remains flat as projected.