You are driving a slow agricultural vehicle on a winding country road where overtaking is difficult, and a long queue of vehicles has formed behind you. What is your obligation under StVO § 20 and § 67?

1. Move onto the hard shoulder and continue at the same speed
2. Stop immediately in the traffic lane so the queue can pass
3. Pull in at the next suitable lay-by, wide verge or bus bay when it is safe, and let the following vehicles past
4. Switch on the hazard warning lights and keep driving at the same speed