A 17% growth in distributions translates into the dividend payment doubling almost every four and a quarter years on average. If we check the dividend history, going as far back as 2002, we could see that Norfolk Southern has actually managed to double dividends almost every four and a quarter years on average. The item to add however was that in 2000 the company did cut its dividends by more than 50%. Therefore, just like we saw with Union Pacific, while the dividend is likely sustainable, this is a cyclical company which is more likely to cut distributions than your typical consumer staples or healthcare dividend stock. So even if you plan on holding for the next 100 years, there will be hiccups and dividend cuts are likely every one or two decades.
In the past decade, the dividend payout ratio has more than doubled from a low of 15.40% in 2005 to 34.70 in 2014. The high percentage in 2009 was mostly an aberration, as earnings seem to have been hit by the Great Recession. A lower payout is always a plus, since it leaves room for consistent dividend growth minimizing the impact of short-term fluctuations in earnings.