My kids have all taken a school bus at some time in their academic career and for the most part I have never worried about their safety. When my kids were younger and in elementary school we lived close enough to the school that I would walk them or drive them if the weather was bad.
We then moved to an area that didn’t even provide school buses so my kids had to bike to school everyday and if the weather was bad I would drive them, but now we’ve moved once again and for the first time all four of my kids take the school bus every day.
They’ve never had any issues with their bus but my youngest is also almost out of elementary school, so I don’t really worry about them anyway. If I had a preschooler or kindergartner taking the school bus I think I’d maybe be a bit more worried about their safety and bus protocol to ensure no child was ever left behind, because no parent ever wants to worry about their child being forgotten somewhere.