Recent news stories about the Department of Transportation deferring $130 million in roadwork because it doesn’t have the money highlighted a larger problem. After working hard on efficiency, Maine will ultimately need more revenue or risk making travel in Maine even more difficult.

Gov. John Baldacci has created a working group to find ways to fund some of these projects. Beyond the current shortfall, however, Maine already had a $1 billion backlog of road and bridge repairs. Many of these projects have languished on DOT lists for years waiting for funding. Highway projects are funded, in addition to federal dollars, from the state’s highway fund and by bond issues. The highway fund gets nearly 70 percent of its money from fuel taxes. Although the state’s tax on gasoline can now be raised by the Legislature every two years, it has not kept pace with inflation.

Compounding the gas tax shortfall, the highway fund also covers much of the cost of the state police and is a target of lawmakers looking for money for other purposes. Just last session, they approved taking $7 million from the highway fund to pay for the Maine State Ferry Service.

At the same time, the use of Maine’s roadways has increased significantly, increasing the need for repairs and upgrades. In 1970, there were 500,000 registered vehicles in Maine. Today there are 1.4 million. During the same time, the number of miles driven has more than doubled and the proportion of freight shipped by road has also increased.

To make matters worse, Maine has a lot of roads considering its small population. There are nearly 23,000 miles of public roads in Maine, compared with about 16,000 in New Hampshire. The Maine DOT is responsible for 8,408 miles of highway while the New Hampshire department is responsible for 4,115 miles.

The spreading out of Maine’s population and the increased commuting on back roads comes at a price. How to pay that price should be a topic of conversation during the next and subsequent legislative sessions.

Oregon is experimenting with a system to charge drivers per mile driven. Especially because it does not account for vehicle weight, this is a crude system that does not truly reflect user impact.

Faced with the same problem of fuel tax growth being far outpaced by construction needs, the federal government is considering taxes on hybrid vehicles and other means to raise highway revenue. A recent report by the U.S. Chamber of Commerce warned that revenue from all levels of government will fall $500 billion short of what is needed to maintain pavement and bridge conditions through 2015 and $1 trillion short of what is needed to improve the nation’s highway infrastructure.

The study recommends that the federal fuel tax, which has been 18.4 cents a gallon since 1993, be indexed for inflation. The House Transportation Committee last year backed raising the tax to help pay for the massive federal highway bill. The administration warned that the president would veto a bill that raised taxes and the measure was dropped.

Taxing hybrid cars is not the solution. Passing much larger bond issues would help. But, ultimately, drivers who use the roads a lot, especially if they drive heavy vehicles, will have to pay more.