When faced with an impending head on collision with a huge runaway truck, there are only a few options. One of the more ineffective options would be soiling one's pants.
An effective option is to immediately put the car into reverse and get the hell out of there. That's what this driver did.
The driver in the video is seen pulling up a hill where a road crew is working. As he gets to the middle, the road crew's truck suddenly starts to roll down the hill. Instead of crying, or shitting, the driver takes action, quickly shifting into reverse and backing down the hill to avoid the truck.
It's an Indiana-Jones-boulder-rolling-towards-you kind of moment. Except this time Indy isn't running and it looks like he's probably driving an economy hatchback.
(Hat Tip to $kaycog!)