In response to the current solid state of transportation stocks, Forbes asked top analyst Bear Stearns' Edward Wolfe to suggest a few companies investors should keep an eye on. Wolfe advises that rails should be bought at 13 to 14 times forward earnings and should be sold when they are above 16 times forward earnings.

While some analysts are suggesting Burlington Northern Santa Fe (BNI), Union Pacific (UNP), and CSX (CSX) due in part to Warren Buffett and Carl Icahn’s interest in the companies, Wolfe recommends Canadian National Railway (CNI) and Norfolk Southern (NSC). Canadian National Railway has the industry's best operating margin at 40% vs 24% for US rails. Norfolk Southern is estimated to trade 14 times earnings over the next year.Wolfe also recommends Expeditors International (EXPD) because only 2% of its revenue comes from freight movements in the United States and the Hub Group (HUBG) for its solid annual earnings growth of 50% over the previous 3 years.