I walked to and from school, but got the bus to come home at lunchtime and get back in time. My mum used to pick me up and walk with me until I was seven and she had my brother. By that time, my sister was five, and had started school. I was responsible for seeing that she also got on the bus (a public bus, not a school one) and got home safely. I can't imagine a 7 year old being allowed/expected to do that nowadays.
The conductor was always the same man, who must have had a regular shift on the route that went from the school past our house. He was a kindly soul, and used to sell the children who got on (we weren't the only ones) tickets to Fairyland - they were 2d, if I remember correctly. I was capable of getting off at the right stop, but I'm sure that he would have reminded us if we forgot.