Quite a few years ago I was a passenger with my wife driving the Mini we had at that time, we were leaving Amsterdam on one of the autoroutes in the rush hour. The traffic was very heavy with all lanes full.
The inside lane was moving at about 60mph, the middle at around 70mph and the outside around 80mph. there was no braking or headlamp flashing by impatient drivers.
We had travelled a few miles before I worked out what was happening.
If a car on either of the inside lanes wanted to move out to overtake he would use his indicator to let faster cars know he wanted to move out, immidiatly a car in the faster lane would slow to let him move out because he new that the car he let out would immiediatly move back in, which they always did. We tried it and it worked every time.
There is no way this would ever happen in the UK due to lack of driver training, morons, ignorant prats, what ever you want to call all the idiots on our roads. You just have to put up with them.
Don't let them grind you down!