People just want to get from A to B. Driving etiquette is non-existent. Manners? They went out the window along with things like consideration, care, thoughtfulness.
cb1965 exemplifies this.
No I don't, but I just think it's a question of perspective. Yes it's crap driving on behalf of the person joining, but it's hardly crime of the century!
Let's face it - if we all went around getting upset about every bit of poor driving we see then we'd all be on the blood pressure tablets in no time. Plus who here can absolutely hold their hand up and say their driving is always beyond reproach?
To me you can handle it two ways
1) Slow down for a few seconds and let them in, tut under your breath, get on with life. Total time out of life lost: 3 seconds!
2) Force the issue where you make them aware of their 'crime', chase them down, stop and remonstrate with them, risk getting a kicking in doing so. Set off again with raised pulse and stress levels higher than they should be. And to boot...total time out of life lost: 3 minutes! Sensible, logical and intelligent response? Nope, not even close!