Oct. 3. 2008 - Federal Express, which currently operates one of the largest hybrid-electric truck fleets in the world, is still well behind on its plan to convert 30,000 medium-duty trucks to hybrids by 2013 - because there isn't enough of a market for the fuel-efficient vehicles, Fast Company reports.

When FedEx made this commitment five years ago, it was betting on a huge hybrid market about to explode with the help of government incentives. The company aimed to position itself as a leader in the market by offering its engine technology to manufacturers, according to Mitch Jackson, FedEx's director of environmental affairs and sustainability.

"We were optimistic that if we were out there helping manufacturers to sell it, then others would follow and create the market," Jackson says.

Unfortunately for FedEx, that didn't happen. Thanks to a 75% premium for commercial hybrid engines, along with government incentives that never materialized, the company hit a major roadblock.

"We would like nothing more than to put more of these incredible vehicles on the road, but they are very expensive," said William Logue, COO of FedEx's U.S. express-transportation subsidiary, in testimony before Congress in 2007.

Logue asked lawmakers to mandate fuel economy standards for commercial vehicles - and eventually they listened. Last year Congress passed the Energy Independence and Security Act, which establishes minimum mileage standards for commercial vehicles.

Yet those standards aren't expected to take effect until late 2010, and FedEx finds itself with only 172 medium-duty hybrids on the road today.

Other companies, including UPS, Coke, SC Johnson, and Cox Communications, are also buying hybrids for their fleets, however. FedEx hopes that higher demand for the alternative vehicles will, over time, drive down the price of hybrid commercial engines.

FedEx now says it has not given up on its goal to get 30,000 medium-duty hybrids on the road, but that 2013 deadline will have to be pushed back considerably.