Norfolk Southern Corporation NSC has announced a few leadership changes.Greg Comstock has been promoted to vice president of network operations from his previous position as the general manager of network operations center and general manager in the Southern Region. Comstock is said to exercise stringent cost-control measures, thereby generating efficiencies. He oversees Norfolk Southern's Network Operations Center and his work includes centralized dispatching as well as related service and support functions. Lorri Kleine, previously working as senior general counsel of workforce, properties, insurance risk management, has now been raised to the position of vice president law. Being a key member in the Norfolk Southern Law team since 1994 and having expertise in managing complex, high-profile and sensitive legal matters, Kleine looks into the legal, claims, investigative, compliance and risk management matters of the department.Additionally, Patrick Whitehead has now been promoted to the vice president post in transportation. Previously, he served as assistant vice president mechanical and general manager in the Northern Region. Like Comstock, Whitehead too is an aggressive cost controller and should enable the company to generate significant efficiencies. An important element of his role includes the execution of TOP 21, Norfolk Southern’s precision scheduled railroading operating plan.The company is making constant efforts to streamline its operations by curbing costs. In line with its endeavors to improve efficiencies, Norfolk Southern’s operating ratio (operating expenses as a percentage of revenues) in 2019 improved to 64.7% from 65.4% a year ago. Fellow railroad player CSX Corporation’s CSX operating ratio improved to 58.4% in 2019 from 60.3% a year ago. Meanwhile, during the same period, this key measure of efficiency improved 140 basis points (bps) to 59.9% at Canadian Pacific Railway Limited CP. The same improved 210 bps to 60.6% at Union Pacific Corporation UNP as well.More Stock News: This Is Bigger than the iPhone!It could become the mother of all technological revolutions. Apple sold a mere 1 billion iPhones in 10 years but a new breakthrough is expected to generate more than 27 billion devices in just 3 years, creating a $1.7 trillion market.Zacks has just released a Special Report that spotlights this fast-emerging phenomenon and 6 tickers for taking advantage of it. If you don't buy now, you may kick yourself in 2020.Click here for the 6 trades >>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report Union Pacific Corporation (UNP): Free Stock Analysis Report CSX Corporation (CSX): Free Stock Analysis Report Norfolk Southern Corporation (NSC): Free Stock Analysis Report Canadian Pacific Railway Limited (CP): Free Stock Analysis Report To read this article on Zacks.com click here.