In some ways, urban parcel delivery is the ideal duty cycle for electric trucks. Daily routes are usually under 100 miles, and all trucks return to a central location at night--ideal for recharging.

Federal Express, which has a large fleet of green and alternative vehicles, is now putting its first all-electric trucks into service.

Four electric delivery trucks, specially built just for FedEx, will go into service in June in and around the Los Angeles area.

Two of the trucks, from Navistar, are based on designs from UK firm Modec, a startup that has already supplied 10 trucks to FedEx for London, with another five on order for Paris.

The other two are from a supplier that as yet has not been named.

"In 2004, [FedEx was] the first global company to invest in hybrid-electric commercial trucks,"  said John Formisano, vice president, Global Vehicles, FedEx Express, "and now we're introducing the even cleaner all-electric parcel delivery truck."

One of the Navistar/Modec trucks was unveiled last week in Chicago, and it will travel and be exhibited along the historic Route 66 as part of what FedEx calls the "Charge Up Route 66" tour. Its progress can tracked on the FedEx website.

Its ultimate goal is the Brainstorm Green conference put on by Fortune magazine from April 12 to 14, to be held in Laguna Niguel, California. Mitch Jackson, VP for environmental affairs and sustainability, will present at the event.

FedEx CEO Frederick Smith testified last month before a U.S. Senate subcommittee, advocating for a comprehensive national program to encourage more affordable electric vehicles.

FedEx has a remarkable fleet of 1,860 alt-fuel vehicles of various sorts, including hybrids and plug-in hybrids.