Dear Road Rager...
Doctor George commends you for your willingness to look honestly at yourself. Yes, signs of road rage do include the actions you describe, plus others such as: honking your horn or flashing your lights (other than as a legitimate warning), retaliating (cutting in front of, tailgating, braking sharply or slowing down after passing), speeding, wishing other drivers would crash, breaking traffic laws when no one else is around, and getting into a verbal and/or physical altercations with other drivers.
There are many inconsiderate drivers. In fact, most of us are probably inconsiderate at one time or another, such as when we're under pressure and in a hurry, but there are times when other drivers' seem to go beyond being hurried, to a lack of consideration, to downright rudeness and disrespect. For instance, when someone cuts in front of us, and then slows down, we often respond as if the other driver is intentionally obstructing us. At times like this, our frustration can tip us over the edge into rage.
Fueling our rage is the false sense of power we have when we're in a car. Since we're driving a two-thousand pound piece of metal, we feel much more formidable than we do at other times. This false sense of power gives us permission to go from frustration to rage: something we normally don't do when we feel more physical risk.
Our sense of instinctual territorialism contributes to, and even makes us feel justified in, our rage. In our cars, we have an expanded sense of personal space that stretches out a few hundred feet. Thus, we feel we have exclusive rights to that zone, and we resent others for entering without our permission.
The lack of control, that we feel from not getting our way, is increased when our life feels out of control. People cutting us off represent an entire world out to get us. If we're feeling like a loser already, then we will fight anyone taking anything more from us, such as our right to get where we're going as fast and unhindered as we desire. If we encounter crowds in our day-to-day life, there can also be a feeling that there are not enough resources to go around, and we feel a need to hurry to get ours before they're all gone.
Problems on the road become symbolic of our not getting anywhere in our lives. The distraction of the external frustration of driving can be an excuse to blame others instead of examining how we are leading our lives. We displace our bad feelings about ourselves onto our experiences on the highway. And, the fact that we feel anonymous in our car, makes us feel we can get away with uncivilized behavior.
Even with all of these contributing factors to road rage, there are things we can do to help the situation. For instance, every time we get in the car, we can tell ourselves that people will probably drive badly and that we are not going to take it personally. We can leave earlier and reduce the impact of other people's behavior. We can examine our lives and seek to achieve a balance, so that we are not so busy that we are always in a hurry. There are advantages to moving at a slower, more contemplative pace: we can better appreciate the good things in our lives.
We can adopt the attitude that other drivers are free to do anything they please and that we will not retaliate. We just let them cut in front of us if they want to. We don't exaggerate the importance of a relatively small thing in the bigger picture of life. If we can overlook the incident, we find that our rage will usually dissipate after a couple of minutes anyway.
Another (admittedly sort of weird) technique is to imagine that we are space travelers and the other cars are asteroids and meteors that may cross our path at any time. We see the cars merely as objects, and as such they do not have it in for us; they are just part of a dangerous environment. So, we must use defensive driving by planning for them, avoiding them and not taking their intrusions personally.
For those who are not helped by the above-mentioned suggestions, it's possible that the road rage (among other disproportionate expressions of rage) is the result of unresolved issues from the past. In those cases, professional counseling can be effective.
So Rager, this is a very long answer to a very short question; and, as you noticed, Doctor George did not directly diagnose your behavior. The reason is that, with this information, it's a question you can answer on your own. Many of us, including Doctor George, would do well to examine our behavior while driving and elsewhere. And, all of us can stand to either develop or increase our level of graciousness. It might be surprising to some that engaging in gracious behavior counters our feelings of road rage. After all, etiquette evolved in society to keep the beast within each of us under control. Being polite keeps us safe from the more primitive reactions humans are capable of. Graciousness empowers us with others because we are in control of our own actions and reactions. And, when we act with kindness towards others, we stand a better chance of being kinder to ourselves.