A semi truck's four blind spots are located:
In front of the cab = 20 feet
Behind the trailer = 30 feet
To the left of the truck backward diagonally
To the right of the truck backward diagonally
A truck blind spot is a “No-Zone.” If you’re in that area, the truck driver cannot see you. Make sure that you can see the truck’s side mirrors. If you must enter a truck’s blind spot, spend as little time there as possible.