Found this to be a realistic view of the coal freight segment of business for UP. In light of the recent decline in this segment, this Forbes article predict single-digit growth for UP throughout 2019 but doesn't see it as something that can bring any significant boost to earnings, at least for the time being
https://www.forbes.com/sites/greatspeculations/2018/12/17/what-to-expect-from-union-pacifics-coal-freight-business-in-the-near-term/#2a85c8606eb5