The railroad is growing more efficient during a period of soft demand. Union Pacific (UNP 4.71%) managed to grow net income in a flat revenue environment, and investors are taking notice. Shares of the railroad company are up 5% as of 2:45 p.m. ET after Union Pacific topped earnings expectations. Progress in a "challenging" market Union Pacific earned $2.69 per share in the first quarter on revenue of$6.03 billion, ahead of Wall Street's $2.52 per share on sales of$5.98 billion guidance. Operating income ...