Driving down a slip road to join a dual carriageway. Two cars coming along the road I'm joining. First pulls over into fast lane. Second towing a caravan doesn't (despite it being empty....) I could accelerate, drive normally and join the road ahead of te caravan safely. Except there's 2 cars in front of me, on the slip road. The one in front slows and slows and almost stops. The one behind him does the same. They could all have just sped up and pulled out.
What should car 3 (me) do? Stay behind them and also stop at the end of the slip road? Speed up and pull out, and prevent them from doing so (although having almost stopped they can't anyway)? Speed up, pull out and cross to the outside lane?
I was a distance behind the two in front.