The value of fitting dash cams into trucks is illustrated by this incident with a Toyota Prius pulling out into the path of a fully loaded truck at highway speed. The consequences could have been much worse for both the car and truck.
After the police saw this footage from the truck the car driver was fined for providing a false statement to police.
Further illustration is provided by this vision of a Volvo driver completely oblivious to other vehicles on the road surviving as a result of the driving skills shown by the driver of the fuel tanker involved.
In the name of balance, this clip of a truck driver who is clearly not paying attention was picked up on a South Australian traffic cam.