A UPS delivery person offloads packages from a truck in New York's financial district March 5, 2014. United Parcel Service Inc, the world's largest courier company, said it would buy 1,000 propane-fueled delivery trucks and install 50 fueling stations in the United States as it expands its already-large fleet of alternative-fuel vehicles. REUTERS/Brendan McDermid (UNITED STATES - Tags: BUSINESS ENERGY TRANSPORT)