United Parcel Service is adding 306 alternative fuel vehicles to its “green fleet,” including 167 compressed natural gas (CNG) delivery trucks and 139 propane delivery trucks for its operations in North America.

UPS is also launching an initiative to use biodiesel fuel in its ground support vehicles at the UPS Worldport air hub in Louisville, KY, said Robert Hall, UPS director of vehicle engineering. A $515,000 federal grant is helping offset some of the cost of building a fuel infrastructure at the airport. UPS plans to use a 5% biodiesel blend of fuel to run 366 ground support vehicles starting early next year.

The CNG trucks — manufactured by Freightliner Custom Chassis and equipped with Cummins Westport engines — will be deployed early next year in Dallas, Atlanta and four California cities, including Los Angeles. They will join more than 800 such vehicles already in use in the U.S., said Hall.

The new propane-powered vehicles — made by Workhorse Custom Chassis with propane engines provided by Baytech Corp. — join nearly 600 propane trucks already operating in Canada and Mexico.

UPS's global alternative-fuel fleet now stands at 1,629 vehicles and includes CNG, liquefied natural gas, propane and electric and hybrid-electric vehicles. According to Hall, the company also is working with EPA on a hydraulic-hybrid delivery vehicle.