How would you prepare your 8-year-old for walking to school alone?

My son is 8-years-old and in the third grade. He is a walker this year, for the first time ever. He’s been in school for 2 weeks now and each day I walk with him to and from school. We have been discussing the basic safety things (like looking both ways before crossing the street, not getting in a car with anyone else,going straight to school and coming straight home), but I’m worried I may miss something important. So, I’m hoping all of my fellow jellies can tell me anything else I should talk to him about walking to and from school before he starts doing it without me.