Fuel spillage during locomotive refueling is expensive, as is maintaining spill collection and containment systems, and waste treatment costs. The Association of American Railroads has developed the first standard for a locomotive refueling system for North American railroads. The locomotive fueling interface standard is an open, non-proprietary standard designed to prevent fuel spillage. Prototype equipment was successfully tested at the Transportation Technology Center and field-tested by seven North American railroads and found to operate reliably and prevent spillage. The standard represents a shift from pollution control to pollution prevention regarding environmental protection during refueling. Cost-benefit analyses indicate that the savings due to reduction in energy and environmental costs that railroads can expect to accrue are likely to pay for the new equipment in one to three years, with the principal benefit coming from the reduction in waste treatment expense.