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A
The same as a single tractor-trailer
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B
Significantly more — each additional trailer adds its own full set of marker lights, clearance lights, tail lights, stop lights, and turn signals; the total number of lights on a triples combination can exceed 70 individual lights
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C
Triples only require brake lights to be functional
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D
Only the front and rear lights of the overall combination
Why this is the answer
LIGHTING INSPECTION on multi-trailer combinations is substantially more involved than on a single unit because federal lighting regulations require each trailer to have its own complete set of lights. LIGHTS REQUIRED PER TRAILER: Clearance lights (amber front, red rear); side marker lights; identification lights (three lights on center of front and rear of each trailer over 80 inches wide); stop lights; turn signal lights (front and rear); tail lights; conspicuity reflective tape or reflectors; underride guards with lights. TOTAL COUNT: A complete triples combination (tractor plus three trailers) can have 70-100+ individual lamps and reflectors. PRE-TRIP REQUIREMENT: All of these must be checked and functional before driving; a burned-out marker light on the second trailer is not visible from the cab; the only way to verify all lights is to walk the entire combination while a helper cycles the lights, or use a light board system; PRACTICAL TECHNIQUE: Walk the complete combination — not just the tractor and rear trailer; activate turn signals, brakes, and markers systematically; note any non-functioning lights for repair before departure; FEDERAL REQUIREMENT: FMCSA regulations (49 CFR 393) require all required lights to be operational; a CMV with non-functioning required lights can be placed out of service at a weigh station.
Source: FMCSA CDL Manual, Chapter 7, Doubles and Triples, Inspection, Lights