Putting the bus stop on a major road without adequate place to stand is a problem. But a 5 year old is totally capable of waiting for a bus, given the appropriate location to do so. Even more so in a typical suburb, where there's likely several of them waiting at the same place (when I was a kid, we walked half a block to the corner and waiting in a group of ~5-~15 kids).
1st grade is probably too young to wait alone. But by 3rd grade I'd expect a child to be able to bundle themselves up.