On a conventional road with one lane in each direction and delimited by a continuous line, if a truck is driving in front of us at an abnormally reduced speed, can we overtake it?

For it to be considered a passing manoeuvre and to be able to pass the truck even crossing the continuous line, the truck would have to be completely immobilised. If the truck is moving, even at an abnormally reduced speed, it is considered an overtaking manoeuvre, which we cannot perform.