WASHINGTON - Another shortcoming of the Energy Policy Act was that the legislation did not require fleet managers to track vehicle locations. The fleet grew, but no one knew how it was taking shape, according to the Washington Post.

This discouraged private investment in fueling stations was because the industry needed better data.

"I have to be able to justify it economically. I need a business plan that shows it's worth the investment for my costs of getting the fuel there and putting in a station. The best data every time is where the federal fleet is located," said Curtis Donaldson, president of Texas-based CleanFuel USA, which builds propane and E-85 stations.

To remedy this, legislation passed in 2005 requires agencies to seek an exemption or waiver from the Energy Department for each flex-fuel vehicle it owns or leases that is more than five miles or 15 minutes from the closest ethanol station. (Agencies also can seek exemptions if E-85 costs at least 15 percent more than standard gasoline. There were no such waiver requests this fiscal year.)

Sixty-one percent of the fleet—more than 67,000 vehicles—received waivers for 2008-09, the second year data were reported.

The waivers did offer a valuable tool: ZIP code locations for each exempted vehicle that could be fed into an Energy Department database and shared with companies that build fuel stations.

The data, however, do not identify the location of the other 39 percent of the flex-fuel fleet that also struggles to find E-85, an important problem to solve since these vehicles run on the fuel 8 percent of the time.

It is also unclear whether vehicles granted waivers are truly too far away from the E-85 stations to use them. The Washington Post's analysis, comparing locations of exempted vehicles with E-85 fueling stations, shows that 13 percent of the vehicles are within five miles of publicly available ethanol pumps.

Energy Department officials said some agencies may have secured waivers because of other factors, including stations that do not accept a government credit card or that have unreliable E-85 supplies.

In urban areas, exemptions were typically granted because traffic congestion made even a two- or three-mile drive costly and time-consuming.

The GAO said its analysis showed that future improvements will rely on better data. And it is time for the government to reassess the original vision for the fleet, the agency said.

"It can be a role model, a leader," said Mark Gaffigan of the Government Accountability Office. "And it should."