What additional equipment may be required for combination vehicles beyond what single trailers need?

Answer: B — Auxiliary brake systems or additional reflective devices

Combination vehicles, such as doubles and triples, often require additional safety equipment due to their increased length and complexity compared to single trailers. This necessitates the use of auxiliary brake systems, which can assist in providing extra stopping power and safety when handling larger loads. These systems help enhance the vehicle's braking capability, especially when traveling downhill or in adverse conditions. Additionally, the regulations may mandate extra reflective devices for these longer combinations to ensure visibility and safety on the road. These reflective devices are crucial for other drivers to perceive the vehicle's length, particularly in low-light conditions. Together, these enhancements improve operational safety and are essential for compliance with federal and state regulations concerning larger combination vehicles.