Waved out, declined, then abused .. WTF ?#MadDrivingStories #CarNews

So I’m at a minor slip junction to join a dual carraigeway, I want to go into the outside lane. A car in the inside lane is flashing me to come out. I wait as they are in the inside lane and I want to cross to the outside which is busy. The car approaches and the driver is giving it the V’s and the middle finder and screaming through the windscreen at me.

1. WTF, my choice isn’t it !!
2. We hear about intended collision for fraud so I’m cautious.
3. Is it really worth the raised blood pressure of that other driver, I’m chuckling to myself and slightly amazed at the reaction. It’s a fast moving Dual Carraigeway so caution is the first rule for me.

Is there a standard protocol for joining Dual Carraigeways in owns moving into the outside lane ?