VIA Metropolitan Transit, the public transit operator in San Antonio, Texas, is introducing rapid-transit buses that run on compressed natural gas (CNG) as a part of its VIA Primo service.

VIA put four CNG buses on the road last year, the organization tells NGT News. The new 60-foot, articulated buses are manufactured by North American Bus Industries Inc., and VIA is taking delivery of 16 units this year and three more in 2013.

"This vehicle is the first of its kind in San Antonio, and we at VIA are proud to introduce it as our first step toward our goal of becoming a multimodal transit agency," said Keith T. Parker, VIA's president and CEO, in a press release.

The new buses will be put into service when VIA Primo launches in December, VIA says.