Buffet is a big investor in railroads and they are cash flow machines. It is true that they use very mature technology but plenty of people are train people an

Buffet is a big investor in railroads and they are cash flow machines. It is true that they use very mature technology but plenty of people are train people and would get into it if there was money. Because the 4 big freight companies in the US are so large though (and have dual duopolies meaning investment isn't rewarded), only safety/environmental regulations will drive big projects and spending.