49 C.F.R. § 236.813a State, most restrictive.
Title 49 - Transportation
The mode of an electric or electronic device that is equivalent to a track relay in its deenergized position. [49 FR 3388, Jan. 26, 1984]
Title 49: Transportation
PART 236—RULES, STANDARDS, AND INSTRUCTIONS GOVERNING THE INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES
Subpart G—Definitions
§ 236.813a State, most restrictive.