North Carolina is not alone in considering an odometer tax.

Arturo Perez, a fiscal analyst with the National Conference of State Legislatures, said that a number of states are considering a so-called Vehicle Miles Traveled tax.

"There is a sense among many states that there needs to be an alternative to the traditional forms of financing transportation," he said.

Perez said that the gas tax used by many states and the federal government to fund road improvements has not kept pace with inflation in the costs of road-building materials.

Even when the tax is raised, it's not enough, he said. 

According to a 2006 report by the NCSL, 14 states raised their gas tax rates 19 times since 1997, but only three raised them sufficiently enough to keep pace with inflation.

Cigarette taxes have become a popular source of state revenue.

According to research by the Campaign for Tobacco-Free Kids, 43 states, the District of Columbia and several U.S. territories have increased their cigarette tax rates more than 75 times since 2002, when many states faced tight budgets due to the recession.

Arturo Perez, a fiscal analyst with the National Conference of State Legislatures, said the tax has been targeted for several reasons: It is considered more voluntary than other taxes, smoking is considered unhealthy, and some groups believe the tax would cut smoking rates.

"It is a tax that is now viewed as something that is more palatable to voters," he said.

Perez said that the cigarette tax is the most frequently targeted of so-called "sin taxes" on junk food, alcohol and tobacco. In many cases, he said it is directed to anti-smoking programs and health care.

Gov. Mike Easley's proposed budget calls for increasing the state cigarette tax from 35 to 55 cents per pack. It is currently the seventh-lowest in the country.