AUGUSTA – A $637 million budget for roads and bridges, overshadowed by the much larger budget for general state services, moved toward final approval Wednesday in the Legislature.

The two-year transportation budget, which pays for highway and bridge improvements and maintenance, state police and a variety of other transportation-related services, calls for the elimination of indexing of fuel taxes, which provide most of the budget’s revenue.

Under Maine’s decade-old indexing system, fuel taxes are automatically adjusted to reflect increases in consumer prices. The highway budget for the two years starting July 1 calls for indexing to end as of July 2012, saving motorists an estimated $5.26 million in the first year.

Gov. Paul LePage and some Republican lawmakers objected to having fuel tax increases on “autopilot” and called for the elimination of indexing as the budget was prepared.

Rep. Richard Cebra, R-Naples, House chair of the Legislature’s Transportation Committee, who also sponsored a bill to dump indexing, said Wednesday that the savings to motorists will compound in years after 2012. Budget documents projected savings of about $14 million in the fiscal year starting July 1, 2013.

The loss of funding will not immediately cause a reduction in highway work and other transportation services, but the revenue loss must be made up over the longer term, he said.

“There are other ways to fund it. We have to find long-term ways to fund” the budget, Cebra said.

Among the ideas that have been mentioned are diverting a portion of the state sales tax for motor vehicle-related items to the highway fund.

Democrats call the highway budget “shortsighted” and say it ensures potholes on Maine roads well into the future.

The highway budget under review would eliminate 66 vacant positions, most of them in the Department of Transportation, and includes pension and health insurance reforms that are part of the $6.1 billion general fund budget.