Mind wandering is common during driving. Scientists have investigated mind wandering in volunteers during a driving simulation. Astonishingly, during the simulation, the volunteers reported mind wandering 70 percent of the time. The researchers could identify specific changes in brain patterns when the volunteers were mind wandering, but need to do further work to clarify if it is dangerous during driving. Source 9p.
I think of all kinds of things while I drive but I still pay attention to the road. The more traffic that is around the less my mind wanders. When I am in stop and go traffic my mind is focused on traffic and those around me as usually someone is getting upset that they are not going fast enough.
KN,
I'm the same as you. I also play a game where I ask myself what color, make, and model car is behind me, to my left, right and then I look in my mirrors to see if I'm right. I also continuously think of what the cars around me could do and what I'd do. It helps to keep me focused.