Wow, is that because you live in a bad area? My husband actually worked at the school, so he drove them every morning and back in the afternoon, so it was a piece of cake.
This year he got a new job, so I decided to homeschool, not just because I would have had to drive them every day, but because it was terribly expensive to send them.
You could try driving him to school youself for a little while (if the school isn't too far away) and see if there are other parents who live farther out who don't use the bus and who wouldn't mind carpooling with you.
Otherwise, I don't know what to tell you. I would be very nervous if my kids had to walk to an area that I couldn't see to wait for the bus, and I live in a relatively safe neighborhood. I would also make sure that you caution him about not talking to strangers and running if someone he doesn't know approaches, stuff like that, which I'm sure isn't something new to him, but it's something you will have to mention when and if you decide to give him the grown-up responsibility of making it on the bus without incident.