Pretty well all driving phobias are set up by a one-off learning event.
It would be natural to assume that this event has to be something really traumatic and life-threatening like a road traffic accident. But if it had been, it would most likely create some form of short-lived post-traumatic stress disorder (PTSD) and a natural avoidance of driving for some time afterwards and this is slightly different in nature and structure to a driving phobia. So many people with a fear of driving will say they don’t know when their thing started because they are searching their minds for something horrific.
The reality is that probably 95% or more of driving phobias start with something milder – like suddenly feeling a little strange when driving at speed on a multi-lane highway. Something like:
“I was just driving along and I tried to overtake a truck….. and couldn’t do it and felt a bit panicky and weird…. and managed to drive on then thought nothing of it until it happened again the next day.”
This kind of experience would probably hold true for more than half of all set-up events for driving phobias.
If you are following the math(s) then you can see that there is a 9 out of 10 chance that your driving phobia was caused by a relatively mild, one-off learning event. There is a high probability that it started on a multi-lane highway when you were much more stressed than usual.