Five hundred years from now, when historians look back at the 20th and 21st centuries, they will focus on one variable that played a role in more global events than any other: oil.

Whether it's accusations of going to war to protect oil interests, having production interrupted by foreign revolution, or simply worrying about how much it costs to fill up a tank of gas, we all have the black gold on our radar.

The death of trucking?
Back in 2008 -- when the cost for a barrel of oil shot north of $120 -- anyone who had to move merchandise across the country started to reassess their options.  It was already accepted wisdom that moving goods via railroads was more fuel efficient than semi-trucks -- but when gas prices rose so precipitously, railroads also became the financially efficient mode of transportation.

Such economic realities were a boon for rail companies such as Union Pacific (NYSE: UNP) and CSX (NYSE: CSX). Though they, too, had to deal with the 2008 recession, profits surged 37% and 47%, respectively, from 2009 to 2010.

Meanwhile, companies that rely heavily on oil to help transport goods -- freighters like Old Dominion (Nasdaq: ODFL) and delivery services like UPS (NYSE: UPS) -- are now left with the guillotine of oil hanging precariously over their heads. This all begs the question: Is the future of freight transport dead?

Enter our hero
Canadian-based Westport Innovations (Nasdaq: WPRT), with its engines designed to run solely on natural gas, could solve the trucking industry's problems. The innovative company is not in the trucking industry, nor does it drill for gas, nor does it even have its own factory. Instead, Westport has developed the technology for natural gas engines, then outsourced all of the manufacturing to partners including manufacturing stalwart Cummins (NYSE: CMI).

Though Westport's technology is relatively new -- and the entire trucking industry certainly won't transform its fleets overnight -- initial results look promising. Besides its presence in North America, Westport has begun transforming trucking on the other side of the world as well. It has already shipped 3,600 engines to China, and it's making inroads into India as well.

Foolish takeaway
But tread carefully, Fool. The company has yet to turn a profit. Though falling, research and development costs have eaten up an average 74% of gross profits over the past three years. That, of course, is the price you pay for investing in a company with cutting-edge technology.

If you think Westport could help save the trucking industry -- and in the process, wean us from foreign oil -- I suggest you add it to your watchlist.

If, however, you'd rather dig further into oil stocks, The Motley Fool has created a new special oil report titled "3 Stocks for $100 Oil," which you can download today, absolutely free. In this report, Fool analysts cover three outstanding oil companies, including the stock Fool analyst David Lee Smith calls the "energy king." To get instant access to the names of the three oil stocks, click here -- it's free.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.