Hater of a different kind.

[PARAGON]

Obviously this will sound contrary to what your emotions feel at the time but.... A good option is to try to stop and pull over as soon as you can, making sure you are doing it fast and keeping the other person in traffic and in front of you. This way he will have to make an aggressive move and you will be more aware of what his intentions are AND be able to easily view this through your window.

Worst case scenario here is that he will pull over up in front you and reverse back to you, but even then you are then put back in to the same scenario you just attempted to escape from and can get back into traffic and attempt it again.

Continuing travelling down the road with someone like this, more especially enraging them further this day and age, can lead to an accident or their doing something stupid. You then could be caught in a he said/she said deal or worse, you or yours hurt. By pulling over and making them take a more aggressive stance you have then somewhat relieved yourself of your liability in the eyes of the law by attempting to avoid the situation. In many situations such as this, your culpability is leveled against you for not doing something to keep the situation from escalating and by putting the other person in the obvious aggressor situation you should be held in a better light should something happen.

A scenario could be that he stops in front of you, gets out and approaches your car with something in his hand. He has already shown his tendancy to be the aggressor and should you not be able to merge back into traffic without endangering an innocent driver..... well.....

This is just one of a few possible things one could do.