Joseph Gordon-Levitt is a new kind of action hero: one that most of America's movie-going population could knock out with one punch. Happily, exuberant bike-messenger-chase-film extravaganza Premium Rush makes the actor's lightweight, streamlined frame an attribute rather than a liability, emphasizing propulsion over punch. After picking up a valuable envelope from Columbia University's campus, JGL's fixed-gear messenger, Wilee, is tailed by a psychopath in a Mazda trying to run him down. "Wile E.? Like the coyote?" asks Michael Shannon's crooked cop — the piece's heavy — falling right in with the movie's cartoon concept, popping out his eyes while displaying an undervalued comic ability between moments of genuine pathos. Director David Koepp follows the action up and down the length of Manhattan and — with a sinuously mobile camera — through rush-hour traffic, while showing a respectful know-how of the city's geography. There is a lot of silly bike-is-life philosophy, including Wilee's personal credo of "Fixed gear, steel frame, no brakes," none of which I can speak to because I don't care a tinker's damn about bikes, but I do have an abiding fondness for compact and coherent action movies, and this is surely one.