Nope, it would likely need to be made out of vibranium to do that. With conventional materials (ones that actually exist) the force that hits the bar is spread to the rest of the bus, pushing it forward. If the rear of the bus is solid then bus moves forward and it is possible the bus hits children. If the rear of the bus crumples to absorb the impact any children in the rear of the bus crumple.
The safest thing to do is have the impacting vehicle go under the bus.
Nope, it would likely need to be made out of vibranium to do that. With conventional materials (ones that actually exist) the force that hits the bar is spread to the rest of the bus, pushing it forward. If the rear of the bus is solid then bus moves forward and it is possible the bus hits children. If the rear of the bus crumples to absorb the impact any children in the rear of the bus crumple.
The safest thing to do is have the impacting vehicle go under the bus.