When DS started school, it was half an hour's walk away. At just four, with a really huge steep hill home, it was just too much for him. It was a bit too much for me, but we would walk down the hill to school, then I would walk back up the hill. When I collected him I would take one of those little foldable buggies with me, make him go as far as he could, then pop him in it for as long as I could stand to push it. Lots of us did the same. At first it wasn't so bad, because there would always be an ice cream van outside at the beginning of September, when he started. Bribery can be a wonderful thing and eating it would give him an energy boost, but in October the van disappeared.
I had a car, but was determined to get exercise for myself, not for him! It was a lovely walk, his school was by a river.