Why do cement-truck drivers make twice the hourly wage of school-bus drivers?

Once again, September brings a school-bus crisis. There's just not enough folks willing to take the job. I know I’ve ploughed this ground before, but here’s all it would take to end this never-ending crisis. Pay drivers properly and treat them with a modicum of respect. What is “proper pay?” I say the hourly wage of a school bus driver should be equal to the hourly wage of a cement-truck driver, plus at least one symbolic dollar-per-hour more to acknowledge that a cargo of children is more important than a cargo of cement. Secondly, the cement-truck driver only has to supervise the cement. The school-bus driver has to supervise 40 or more children, who could range in age from two to twenty, all while he/she is driving the bus! That is just wrong! Once those kids are off the bus and on school property, the school boards and the teachers’ unions dictate that every student be under the supervision of a trained professional at all times. Being under the supervision of the bus-driver doesn’t cut it, by my estimation. They’re already doing their job; driving the bus. If you’re asking them to do two jobs for the price of one… well, maybe you’ll have a school-bus driver shortage! Expecting one and the same person to do two jobs simultaneously for a wage they can make at McDonalds guarantees you’ll have a school-bus driver shortage. That's why every school bus needs to have a second adult aboard to supervise the children while the driver focuses on their job; driving the bus.