["I'm generally a calm driver.  But what really agitates me--to the point of wanting to throw something at the other driver--is someone on the right side merging at full speed onto the main road I'm driving on, towards the furthest lane possible...with NO SIGNAL"]
I feel your pain. It's crazy how reckless some drivers can be. I was always taught the importance of using my signals.
I'm a pretty level-headed driver.  But my one pet peeve that really irks me--to the point of wanting to throw something at the other driver--is a driver on the right side merging at full speed into the furthest lane possible...with NO SIGNAL