An electric locomotive (8601) is designed solely to haul or push other rolling stock and carries no revenue passengers or freight in its own body. A self-propelled railway coach (heading 8603) integrates passenger or cargo accommodation with its own traction equipment. A power car that forms part of a multiple-unit train set but carries passengers would generally fall under 8603 rather than 8601.

Both subheadings (860110 and 860120) fall under the same heading and are subject to the same HTS duty treatment, but battery-powered units may face additional scrutiny under EPA emissions regulations if they replace diesel equipment, and their battery systems could trigger separate classification questions for the battery packs if imported separately. FRA equipment approval requirements apply to both types when placed in US rail service.