LOL, the second my kids were old enough to ride the bus, I was like BYYYYYEEE!!!! I got them really excited first though, and it helps that my bus stop is kind of the corner of my front yard and I watch from our huge front window, so they turn around and make hearts with their hands and I blow kisses and stuff (or bang really hard if they're picking on each other, LOL!)
The first few weeks, I walked them to the bus stop and waited for them to be dropped off. That got old really fast. Even if one was sick, the other had no problem going solo to the bus stop.
True statistic: more kids are injured in car accidents on the way to school than riding the bus. The difference is actually HUGE. Talk to the bus driver, just small talk, to get to know them, and rest assured, they have all some KINDS of crazy bus safety drills and lectures at school. I have full faith in our bus system.
I also have the number for transportation on my speed dial, so if the bus is running late, I can call them and they can tell me exactly what the hold up is and where the bus is at that very moment. They're wonderful! I can't tell you how many time's I'd call because the bus was running late, only to have it show up while I was on the phone.
Let your son ride the bus. If you don't do it this year, you're going to still have the same anxiety about it next year. It's going to be harder on you than on him ;) Do you really want to bring this on yourself for the next 15+ years? Driving him to school? Cut the cord, let him GO ;) He'll be fine, just like millions of other kids on a daily basis... and you'll be fine too ;)