It's suggested that the driver needed to manage the situation, in the first place.
Why is it up to the driver? In this case, it's because the driver was the only adult present. But why is that?
The driver should be watching the road, not supervising the passengers. These are two separate jobs. There needs to be a position for someone who makes sure all is calm in the seats, so the driver can focus.
The best drivers might actually tune out the noise and commotion, if any, while they are concentrated on the very important work in front of them.
Where would the money come from?
It would be a big program if implemented schoolwide, citywide, provincewide, nationally. Even with volunteers from among the parents, there would still have to be administration, criminal checks, and so on.
This is probably already being done in many places, whence one could turn for a model.
Why isn't it being done everywhere already?
