2012 Honda Civic Natural Gas
Several states have made concerted efforts to create adequate charging infrastructure for electric cars.
And California now boasts a handful of hydrogen fueling stations, making it the only state with any public infrastructure that supports fuel-cell vehicles.
But Oklahoma may be the only state that can claim a comprehensive network of natural-gas fueling stations along its highways.
The Sooner State now has a compressed natural-gas (CNG) fueling station every 100 miles along its interstate highways, according to the advocacy group Natural Gas Vehicles for America.
The network was built to fulfill a goal set in 2011 by Governor Mary Fallin as part of her Oklahoma First Energy Plan.
It means Oklahoma's CNG fueling infrastructure is now better than its DC fast-charging infrastructure for electric cars.
Natural Gas-powered Kenworth truck (Image: Flickr user TruckPR)
Oklahoma presently has 33 public electric-car charging sites, with 68 plugs, according to the U.S. Department of Energy's Alternative Fuels Data Center.
Of that total, just five sites offer DC fast charging, with 27 plugs among them.
In comparison, Oklahoma currently has 97 CNG stations, according to the DoE.
MORE: Chevrolet Impala Bi-Fuel Sedan Sales Now In Hundreds (Dec 2015)
This infrastructure likely serves businesses with fleets of CNG vehicles and truckers as much or more than it does individual drivers with natural-gas passenger cars.
Sales of CNG cars to private users have typically been very low, in part due to the lack of fueling stations.
The Honda Civic Natural Gas—the most widely available CNG car—was discontinued last year due to low customer interest, as well as low gas prices, which eliminated the per-mile cost advantage of natural gas in most regions.
2015 Chevrolet Impala Bi-Fuel Natural Gas
The natural-gas Civic sold at an average annual rate of just 700 cars in the years leading up to its demise.
General Motors has sold a few hundred Chevrolet Impala bi-fuel sedans over the past year. These models run equally well on CNG or gasoline.
Beyond that, the only options are a host of work trucks and vans, as well as aftermarket conversions of gasoline or diesel cars.