AT&T is marching on with its plans to continue growing its fleet of new alternative-fuel vehicles (AFVs) to 15,000 by 2018.

At the Sept. 16 California Plug-In Electric Vehicle Collaborative ‘Drive the Dream’ event in San Francisco, AT&T announced it will replace 10 percent (55) of its passenger vehicles with plug-in electric vehicles (PEVs) by September 2014.

More than 50 corporate executives joined California Gov. Jerry Brown to discuss opportunities and obstacles to continued market growth, in addition to announcing new corporate commitments to workplace charging, fleet vehicles, and incentives to employees. Under Gov. Brown, the State of California has set the most aggressive clean transportation goals in the country, including creating a charging network to handle 1 million electric vehicles by 2020.

The announcement from AT&T was just one among several announcements and renewed commitments made by the 40 companies in attendance at the event, according to a release from the Collaborative.

Collaborative members from the utility and telecom industries include the California Public Utilities Commission, Pacific Gas and Electric, Sacramento Municipal Utility District, San Diego Gas and Electric, and Southern California Edison.

In 2009, AT&T made a commitment to invest up to $565 million to deploy approximately 15,000 AFVs over a 10-year period through 2018. Doing so was expected to help avoid the purchase of 49 million gallons of gasoline. By the end of 2012, the company had deployed 7,061 AFVs.

In April, AT&T reported a total of 2,082 electric vehicles (2,079 hybrid-electrics and three all-electric models).

Although it is one of the largest EV fleets in the U.S. today, CNG currently makes up the majority of the company’s AFV fleet. AT&T has a goal of 8,000 new CNG service vehicles deployed through 2014.

AT&T is the second-largest commercial fleet in the U.S., based on total vehicles reported for Automotive Fleet’s Top 300 Commercial Fleets listing for 2013.