A driver got so furious when his car got slapped with a boot outside Penn Station that he attacked cops with a meat cleaver, and officers fired 18 shots at the maniac to stop his rampage, cops said.

Off-duty detective Brian O’Donnell, who jumped in to help stop Akram Judeh, 32, was struck in the face with the 11-inch blade and suffered a gash from his left temple down to his throat, said Police Commissioner Bill Bratton.

Judeh — a career criminal — was left splayed out on the street in a giant pool of blood on West 32nd Street and Broadway.(nypost.com)…[+]