Which term describes the area inside a roundabout that supports the rear wheels of heavy vehicles during turning?

• A. The central island
• B. The outer ring
• C. The truck apron
• D. The shoulder

Answer: (C)

Long vehicles need extra space when they turn around a roundabout because their rear wheels follow a wider path than the front wheels. The area around the central island that is designed to accommodate this turning movement is the truck apron. It’s a surface around the island that can handle the rear wheels as the vehicle swings through the turn, helping prevent tire damage and curb strikes. The central island is the solid central barrier, the outer ring is the circulating roadway, and the shoulder is an edge or emergency lane—none of these specifically provide the extra clearance for the rear wheels like the truck apron does.