AT&T recently marked another milestone by adding its 8,000th compressed natural gas (CNG) vehicle as part of the company's 10-year alternative fuel plan. The vehicle, a 2014 Chevy Express, was delivered to a work center in St. Louis.

"With one of the largest corporate fleets in the country, it makes sense for our business and our communities that we constantly seek ways to reduce fuel costs and minimize environmental impact," said Jerome Webber, Vice President, Global Fleet and Transportation Management at AT&T, in a recent statement. "Operating a diverse fleet, which includes alternative fuel vehicles, supports AT&T's commitment to sustainability and exemplifies how we strive to do business."

As part of the $565-million initiative to add 15,000 alternative fuel vehicles to its fleet by 2018, AT&T has also deployed hybrid electric, all electric and extended-range electric vehicles, with more than 10,000 alt-fuel vehicles in 43 states, Puerto Rico and the District of Columbia.