Energy Efficient Railroading

One of my interests has always been railroads (an interest that my older son definitely is picking up). I've got a room that will be dedicated to a model railroad if we ever finish unpacking from our move last year, and I've got a ton of stuff to use in setting it up. Thus, when I ran across this article on CNN.com I was quite interested. General Electric (one of the major locomotive manufacturers in the world) has developed a new locomotive for Peru that runs on compressed natural gas. This allows it to be cleaner and more energy efficient than the old diesel versions, and more useful than the experimental locomotives that have used liquified natural gas. So, is this something that can be put into automobiles?