A school bus driver is being heralded as a "hero" for maneuvering to avoid a head-on crash with a semi-truck Wednesday ...

Dash camera footage ... a tractor-trailer didn't move over and slid through the crash scene. Two troopers can be seen jumping over the cement highway barrier right before the truck plows through ...

He had just pulled over a Hyundai Santa Fe when a semi truck veered onto ... and it was all captured on the cruiser's dash camera. After being hit by the truck, Avila staggered over to the guard ...