The Inception star, who plays a New York bike messenger in the fast-paced film, smashed through the rear windscreen of a cab when a cycling stunt went awry as he sped through real traffic.
He required 31 stitches to a nasty gash on his arm after the accident, but Gordon-Levitt admits he could have ruined his youthful good looks had he reacted any slower to the crash.
He tells BlogTalkRadio.com, "When it first happened I was so flooded with adrenaline that it didn't hurt at all. The scar is here on my arm. I got my elbows up; all the boxing training came in handy. Otherwise who knows what would've happened to my face. It could have been a lot worse because windshields are far more forgiving than trunks or asphalt bumpers. The whole thing was a perfect storm of factors where so many things all went wrong at the same time."
Writer/director David Koepp managed to catch the whole crash on film via his iPhone - and he has decided to include it at the end of Premium Rush so fans can see for themselves just how dangerous it really was.
Koepp says, "There's a bit in the end credits where I shot that bit (the accident) on my iPhone. If you wait 30 seconds you can see what really happened to Joe that day."