My opinion is going to be at odds with some. A couple of years ago when my nurse asked me to walk every morning I did so except for Wednesdays. On that day I didn't walk but went to Tesco for the weekly shop. I always returned my lowest pre lunch sugar readings on Wednesdays and couldn't explain why. In fact I had a mild hypo just before I got back from Tesco on one occasion. .
I live in a rural spot and going to Tesco is a bit of a drive and then there's the trolley pushing etc. I don't know the truth of it but decided it must be an activity that involves both the legs and the arms. Anyway, it worked for me.
My postman has a van (rural spot again) and all the leaping in and out of it and driving it around the lanes is not, in my opinion, a sedentary pastime.
So I reckon, walking or driving are both good.