Crude Oil Advance Tracking Act or the COAT Act This bill addresses safety concerns regarding railroad carriers transporting Class 3 flammable liquids (e.g., crude oil) and other high hazardous liquids or gases. Specifically, the bill requires railroad carriers transporting Class 3 flammable liquids to (1) share information regarding such shipments with state emergency responders, including the number of gallons of the liquids; and (2) include in each annual report information regarding their ability to pay all costs of cleaning up a reasonable, worst-case spill; provides grants for local communities to develop, improve, and implement emergency plans that address responses to high-hazard rail shipments; and provides financial assistance for local projects, activities, and personnel that mitigate the impacts of, and public health or environmental risks associated with, the transport of flammable liquids or gases by rail.