“Salt” is a Hollywood stuntman (and stunt woman) stimulus package, an espionage thriller filled with epic brawls, shootouts and a chase across the roofs of assorted semi trucks and tankers along the highway interchanges of greater Washington, D.C.

What, you think that stick figure Angelina Jolie is the one doing all that derring do? Remember your physics, kids! Girlfriend’s got no throw weight.

The film, originally built as a Tom Cruise vehicle, is about a spy accused of being a sleeper, a deep-planted mole within the CIA. Evelyn Salt is on the run.

We see in the opening scenes how she survived North Korean torture thanks to the love of her devoted spider-expert husband. She may be fleeing her CIA colleagues (Liev Schreiber and Chiwetel Ejiofor) because of her ongoing mental issues over being held captive, because she’s actually a Russian spy completing her mission, or for fear of what one side or the other will do to her husband.

She has her defender (Schreiber) — “Maybe Salt is just who she says she is.”

And her accuser (Ejiofor) — “‘Maybe’ is your department.”

But as good an actress as the Oscar-winning Jolie is, as much experience as she has in action roles playing women “with particular skills,” I never really bought her in the part. She seems too frail to do most of the things director Phillip Noyce has her doing.

It’s a talky film, dropping into long blurts of exposition that stop it in its tracks. And for all its breathless chases, “Salt” has little urgency — the drive that would make this character risk her neck and stack up a staggering body count in pursuit of whatever her agenda is.

Watching her fellow agents stare helplessly at video monitors as she makes her first getaway is laughable. They’ve just let her accuser escape. Uh, turn off Facebook and run after her, fellas! And bring your guns!

A brief if not entirely brisk film, the tale is also interrupted by flashbacks that give us Evelyn Salt’s back-story, snippets of her earlier experience that explain who she is today. And the lack of urgency means it’s a movie that allows us to ponder where it’s going and get there long before the drawn-out finale, with the many “Oh, come on” moments leading up to it.

August Diehl (“Inglourious Basterds”) is miscast as the husband, a fellow not given enough scenes with any emotional depth to them, scenes that would give us the idea that some great big love might be driving Evelyn’s actions.

Noyce, well over a decade removed from his “Patriot Games” action heyday, does well enough by the more preposterous stuff in Kurt “Law Abiding Citizen” Wimmer’s leap-of-logic script.

Salt’s many escapes have enough novelty that were this set in the unreality of “Wanted,” it wouldn’t matter that we don’t see her face doing any jumps, motorcycle tricks or the like.

But all those criticisms aside, it’s still a short-enough time-killer of a thriller — not the worst of the summer, just a long way from the current state of the art.

And not to pour you-know-what on the wound, but Jolie’s days as an action heroine may be behind her. She’s still got the cruel lips. But at some point, a cookie or two needs to pass through them to give her the brawn to pull off this stuff.