What federal requirement applies to converter dollies built on or after March 1, 1998?
Doubles/Triples (T) Endorsement • Free CDL Practice Question
Regulation
49 CFR 393.55 (antilock brake system and ABS malfunction-lamp requirements for trailers, including converter dollies, manufactured on or after March 1, 1998); AAMVA CDL Manual Section 7.1.8, "Antilock Braking Systems on Converter Dollies," p. 7-1
Why This Matters
ABS on a converter dolly helps prevent wheel lock-up and loss of control specifically at the dolly's axle, a key stability point in a doubles/triples combination. The yellow lamp gives a quick visual way to confirm a dolly is ABS-equipped during a pre-trip check.