In the shipping battle of trucks vs. trains, Warren Buffett's wager is on rail.

The next economic uptick - just getting started in some areas - will call Buffett's bet on whether railroads can deliver big earnings.

His $44 billion gamble on Burlington Northern Santa Fe Corp. suggests he thinks three decades of deregulation, consolidation and infrastructure investment have built the engine for the next chapter in the so-called railroad renaissance.

The recession put an emergency brake on demand over the last two years. But with freight volumes set to recover if the economy gains steam, the nation still needs coal and an efficient way to move everything from cars to clothes to corn.

And energy prices are expected to rise, a trend that would favor railroads because they're more fuel-efficient than trucks.