I get this urge frequently and have been getting it since I first began driving a car.  It varies a little each time but it goes something like this.  I am driving high speeds (50 mph or above) along a concrete barrier.  I want to crank the wheel over and slam my car into the barrier causing it to flip in the air or spin out of control.  I always imagine the airbags deploying the glass shattering and the metal crunching.

                                                                                                            Emy in Baltimore, MD

While on an Alaskan cruise several years ago, I stood together with my family on the top of the boat for the big push off and farewell in Vancouver B.C.  I found myself inching away from the edge of the boat, not out of fear that I might fall, but rather out of fear that I might jump to my death.  I have since learned that I was not alone.