قاعدهٔ ۱۷۳ — بزرگراه‌های دوبانده

Dual carriageways. When crossing or turning right, first assess whether the central reservation is deep enough to protect the full length of your vehicle.

• If it is, then you should treat each half of the carriageway as a separate road. Wait in the central reservation until there is a safe gap in the traffic on the second half of the road.
• If the central reservation is too shallow for the length of your vehicle, wait until you can cross both carriageways in one go.