David -
as you can see, everyone is different. A lot depends on you and the rate at which you recover. Your doctor will generally be able to tell you when he/she thinks it's safe. I started driving again 6 weeks post op; probably would have done so a week or two earlier, but I was fairly fatigued and a little unsure of myself, so I didn't push it. I also had the "luxury" of having a driver (my mom) to get me and my kids where we needed to go. If I would have had no transportation, I would have been spurred to start driving that much sooner since it's such a necessity in my life.
As my doc suggested, I started out with small trips until I got used to driving again. I also found it helpful to leave the radio off at first and to drive without my kids so I didn't have a lot of noisy distractions since my surgery left me with SSD. Even today, when the weather is bad and driving conditions are "tough" I turn off the radio so I can concentrate better.
Once I got back to driving, I didn't have any problems with it. Parking was another story - for a long time it was difficult to park between the lines in parking lots. I had a hard time judging where my vehicle was; I thought I was dead center, but after I'd exit my vehicle I would see that I was way over to one side or the other
It's comical to me now, but at the time, it was fairly annoying. From what I recall, others had this same problem - we used to post about it. If you search under "parking between the lines", you can probably find those posts.
Jan