U.S. drivers may soon be taxed by mileage instead of by gasoline consumption, says Transportation Secretary Ray LaHood.

"We should look at the vehicular miles program where people are actually clocked on the number of miles that they traveled," LaHood said in an interview with the Associated Press.

LaHood said the current method of funding transportation projects, a gasoline tax, is failing to generate enough revenue to keep up with funding requests. LaHood called the gasoline tax "antiquated," and cited that transportation funds had to be infused with $8 billion last year in an emergency move by Congress.

"The big question now is: We're into the 21st century and how are we going to take care of our infrastructure needs," says LaHood.

Oregon, Idaho, Rhode Island and North Carolina have all discussed implementing similar programs, and one such program being discussed in Massachusetts would track drivers with GPS systems.

Privacy advocates are gravely concerned about the proposals.

“This is a great example of the problems that often arise when trying to bring into the digital age areas of the economy monopolized or dominated by government,” Berin Szoka, a fellow at the Progress & Freedom Foundation, told the Heartland Institute about Oregon's plan to take drivers based on mileage. “I wouldn’t want the government to have access to my car’s location at any given moment or a complete record of where I’ve driven."

As transportation budgets continue to shrink, government officials at both the state and federal level will be pressured into finding alternative streams of revenue in order to avoid raising the gasoline tax during the recession.