Freight Rail, for example CSX and Union Pacific
The Washington Post scores again with this summary of the boom in the RR industry:
The freight railway industry is enjoying its biggest building boom in nearly a century, a turnaround as abrupt as it is ambitious. It is largely fueled by growing global trade and rising fuel costs for 18-wheelers. In 2002, the major railroads laid off 4,700 workers; in 2006, they hired more than 5,000.