Hunter Harrison told a transportation conference today that the transition to alternative fuels will be long, but new investments in traditional energy sources will dry up because of environmental hurdles.
The country's second-largest railway has seen shipments of crude drop due to declining demand brought on by the dramatic fall in oil prices.
Thermal coal shipments have also waned.
Harrison said the rail industry will have to adjust to a shift to alternative energy sources, just as it did in the 1990s when the U.S. Clean Air Act wiped away 29 per cent of the business at Illinois Central Railway that he ran at the time.
He spoke at the J.P. Morgan transportation conference in New York.