The defendant, of no fixed address, was jailed for life with a minimum term of 25 years by Judge Mrs Justice Brunner KC at Manchester Minshull Street Crown Court on Monday.
Sentencing Richardson, the judge told him he had shown an “astonishing degree of disregard for human life”.
She said: “For every moment you carried on, you were knowingly using your heavy vehicle to cause serious injury to a man who was trapped, injured and completely helpless as a result of your actions.
“You did that because you decided escaping from the scene of an accident was more important than a human life.”
