The U.S. Postal Service has begun pilot testing the use of a three-wheeled electric vehicle in delivering mail in Key West, Florida to reduce its carbon footprint.

The Key West Post Office's T3, which is similar to the two-wheeled personal transporter Segway, has two mail compartments on its sides, pulls a small trailer and is equipped with a GPS and solar-powered anti-theft alarm system. It is easy to maneuver and can fit into narrow alleyways and some sidewalks.

Key West Postmaster Jane Evans said the T3 is applicable to the small island city, where the road speed limit is limited to 30 mph. The T3 runs at 12 mph and one single charge of its rechargeable battery is good for 40 miles.

Operating the T3 is also cost efficient at only 25 cents per day compared to $13 and $15 per day for propane-powered delivery trucks plying Key West, Evans said. Maintenance cost is also lower for the T3 at less than $500 per year compared to $6,000 for the trucks. The T3 cost translates to $50,000 in annual savings for the local post office.

Although one T3 costs $14,000, its California manufacturer, T3 Motion, offers discounted price for multiple orders, Evans said.

The USPS is also pilot testing T3 mail delivery in St. Augustine; Atlantic Beach; Ocala; Phoenix; Sun City, Arizona; and San Diego and Irvine, California. The T3 is already being used by law enforcer and airport security guards nationwide.