What does this sign mean? What does this sign mean?

• A. A bypass joins a dual carriageway

• B. A feeder lane joins an existing lane

• C. Two lanes merge into one

• D. A side road joins a one-way street
•  

  The correct answer is B

   

  Correct. These types of lanes are common in situations where vehicles need to get up-to-speed before joining the lane, e.g. on a motorway. In this case, merge like a zip when traffic is heavy (alternate vehicles take turns to go). When a feeder lane joins an existing lane, it's important to indicate.