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CFR > Title 49 - Transportation > SUBTITLE B—Other Regulations Relating to Transportation > CHAPTER II—FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (Parts 200–269) > PART 234—GRADE CROSSING SIGNAL SYSTEM SAFETY AND STATE ACTION PLANS > SUBPART D—Maintenance, Inspection, and Testing (§234.201 to §234.275) > 234.203—Control circuits.
234.203—Control circuits.
All control circuits that affect the safe operation of a highway-rail grade crossing warning system shall operate on the fail-safe principle.