The one that provides people (the illusion of) liberty through movement.
Honestly, I feel the same way, since most time I spend driving I spend sitting in traffic or something.
When I need to clear my head, I still hop in the car and go for a drive with music. Not also afraid to admit -- I've had some of my most cathartic, emotional-cleansing crys in the vehicle by myself.
In this day and age where there are fewer and fewer places to go to truly be alone with one's own thoughts, sometimes my vehicle is my own personal sanctuary.
However, there really is an element of freedom. You can drive where you want when you want. It's just that the average person sits in bumper to bumper traffic.