When automobiles first began appearing in the United States in the early 1900s, it took a while before a network of roads and gasoline filling stations was developed to allow the market for cars and trucks to really grow. Something similar is in play today with natural-gas-fueled buses, trucks and cars.

For a decade or more, some larger cities have had public transit buses running on clean-burning natural gas. Some fleet vehicles in big cities also run on natural gas.

Because of Pennsylvania’s rich natural gas reserves in the Marcellus Shale formation, there are good reasons to promote natural-gas-fueled vehicles here — the air will be cleaner and the increased demand for natural gas will keep the gas- drilling industry booming in the state, creating jobs and boosting the economy.

Given that, it was encouraging to learn last week that Butler will be getting a natural-gas filling station, the first with access for private vehicles, by early 2014.

The fueling station will be constructed at the Butler Transit Authority’s new facilities in the Pullman Center area.

A part of the program, funded by a $1 million grant from the state Department of Environmental Protection, also involves a gradual conversion of BTA buses from diesel to compressed natural gas, or CNG. The plan also calls for conversion of buses operated by Butler Area Rural Transit (BART) to run on CNG.

The process of vehicle conversion and building fueling stations, to build demand for CNG in transportation, will not be quick, easy or inexpensive. But, despite all that, it should be done.

Texas oilman T. Boone Pickens has been promoting a plan to convert the nation’s fleet of tractor-trailer rigs to run on natural gas. If the big rigs on the highways were fueled by CNG, the nation could pretty much eliminate imported oil. And because the U.S. has massive reserves of natural gas, such a plan is a good way to achieve energy independence, something national politicians have proposed for decades, but never achieved.

Increasing demand for natural gas is important to Pennsylvania’s future economic health, given development of the Marcellus Shale formation. Without increased demand, rising supplies will suppress prices and possibly slow production.

A few public-access CNG filling stations have been constructed in Pittsburgh, the most recent one in the Strip District.

For now, local buses and fleet vehicles, which remain within a fairly limited geographic area, are the only transportation market for natural gas. But as more natural-gas filling stations appear, the demand for CNG-fueled cars could increase.

Certainly, without more fueling stations, few people will be interested in CNG-fueled cars because of the fear they might travel out of range of a fueling station. But once a reasonable network of CNG stations is established, natural gas will be a truly viable fuel for cars and trucks. And that’s good for the air and for Pennsylvania’s natural gas industry.

Today, only Honda sells a CNG-powered car in the U.S. market. But Fiat, a leader in the more advanced European market for CNG cars, is reported to be considering importing those cars to the U.S. as a clean-energy option to other manufacturers’ hybrid or electric vehicles.

The development of the CNG transportation market will not happen overnight, but news of more CNG filling stations, like the one planned for Butler, is encouraging as a necessary step in the development of CNG as a transportation fuel.