Two Republican senators are accusing the federal government of misusing $78 billion in Highway Trust Funds on scenic beautification and other low-priority projects rather than committing money to essential programs to restore major highways and bridges.

Sens. John McCain of Arizona and Tom Coburn of Oklahoma say the Government Accounting Office report released Thursday shows that the nearly bankrupt fund wasted billions over the past five years when it should have been using money earned by the federal fuel tax to maintain the nation's highways and bridges.

"Congress has wasted billions of dollars on low-priority projects like bike paths while bridges are in disrepair. In today's economy, it's inexcusable to continue business as usual when Congress could be supporting state priorities that would save lives, save taxpayer funds, create jobs and truly stimulate the economy," Coburn said in a written statement.

The Highway Trust Fund -- created in 1956 to maintain the country's highways and bridges -- allocated $2 billion to preserve 5,547 facilities for pedestrians and bicyclists, including $878,000 for a pedestrian and bicycle bridge for a Minnesota town of 847 people. 

The fund also allotted $850 million for 2,772 "scenic beautification" landscaping projects along interstate highways from 2004 to 2008, according to the GAO report.

The report also found that $488 million of the fund's dollars went toward "behavioral research" to study and improve safe driving, while $28 million was used to fund the nation's transportation museums.

And $121 million was used to fund 63 ferry projects and ferry terminal facilities, which included $1.6 million for a ferry boat program in Oklahoma featuring morning cartoon cruises with Bugs Bunny on the ferry's flat screen television, the report found.

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While the funding of projects unrelated to highway and bridge maintenance is legal, McCain and Coburn are calling for periodic reviews of such projects they say amount to earmarks that drain a fund that went bankrupt last year. The government is expected to save the HTF from bankruptcy again this year by doling out another $5 billion.

"Congress is about to pass another bailout of the Highway Trust Fund because we have refused to make wise choices about transportation spending," Coburn said.

McCain, a vehement critic of wasteful government spending, said Thursday that the number of highway bill earmarks has "exploded" over the past five years.

"GAO's analysis only confirms that Congress is frivolously spending the Highway Trust Fund for pet projects like walkways and bicycle paths, at the expense of our nation's roads and bridges. Now Congress wants to bail out the Trust Fund by saddling future generations with even more debt. Doing so is irresponsible," McCain said.

FOX News' Molly Henneberg contributed to this report.