Carryfast:
As I said if it looks, flies, quacks, like a crash for cash scam it’s a scam.
The way it was described by the OP sounds just like it could have been what I’ve described.
Hanging around at the side of a truck for ages in the knowledge/hope that it will need to make a lane change and if that doesn’t work they brake harshly for no reason at all when the driver waits and then changes lanes or merges behind them.
I obviously do drive as if these scammer are out to get me that’s why I laugh at them when I see their pathetic scamming antics.Which is often.As I said I’ve actually seen them match my speed, including slowing down to a crawl/stop in lane 1 for example, while trying to stage a side swipe situation, when merging from an entry slip.
It’s reached the point where it’s actually much better to either not accelerate at all on the slip road so as to easily out brake them or accelerate early to a much higher speed so they haven’t got the time to match it.
A similar situation applies during lane changes also be prepared for the inevitable following heavy braking move being their default plan B.
You can add to that accelerating during/after they’ve been overtaken in the hope that you’ll side swipe them when returning to the nearside lane.
It’s all so laughably predictable.There’s a whole industry involving this going on and the law and insurers know it.
I do admire you for one thing Carry Old Fruit…you put a remarkable amount of thought into seemingly random topics 
Carryfast:
It’s reached the point where it’s actually much better to either not accelerate at all on the slip road so as to easily out brake them or accelerate early to a much higher speed so they haven’t got the time to match it.
A similar situation applies during lane changes also be prepared for the inevitable following heavy braking move being their default plan B.
You can add to that accelerating during/after they’ve been overtaken in the hope that you’ll side swipe them when returning to the nearside lane.
It’s all so laughably predictable.There’s a whole industry involving this going on and the law and insurers know it.
‘And coming up shortly on BBC3- Carryfasts Road Wars’