James Mottern's Trucker begins with Michelle Monaghan having a deep, hard orgasm. That's one way to get people's attention, I guess. Satisfied, she climbs off the young man, puts on her clothes, blows off the gentleman's attempts to engage further with her, marches out of his motel room and climbs into her big rig. It's a blunt scene, quietly effective, telling us much of what we need to know about her character, Diane Ford, a long-haul trucker.

A few years ago, Diane walked out on another man, Leonard (Benjamin Bratt), and their infant son, Peter. Now, Leonard is hospitalized with cancer, and Peter needs somewhere to go while his stepmom (Joey Lauren Adams) deals with a family emergency. Diane is stubborn and tough, and she makes no apologies for who she is ("Not everybody's cut out to be like everyone else," she notes), but being genuinely needed causes her to question the way she's lived her life, and to perhaps attempt a connection with her boy (Jimmy Bennett).

In its broad strokes and overall construction, it isn't a stunningly original story; hell, change Diane's sex and toss in some arm wrestling and you've got Over the Top. But Trucker works anyway, thanks to several potent performances and the picture's low-key, easygoing sense of tone and style. Mottram's confessed Alice Doesn't Live Here Anymore influence is clear and pronounced (it shares not only that film's mother-son dynamic but its comfort in track houses and roadside motels); it is also reminiscent of more recent portraits of everyday folks living small-town lives, in films like Sling Blade, Eye of God, and Monster's Ball. As those films did, Trucker avoids the condescending, semi-tragic approach that cosmopolitan writers and directors tend to attach to ordinary lives--the film is matter-of-fact in its view of Diane and her situation, and the natural, unforced dialogue and scene construction doesn't push for effects.

The picture's delicate mood is enhanced by Mychael Danna's atmospheric, ambient score and the sharp, expansive cinematography by Lawrence Sher--the film never feels walled-off or closed-in, a common pitfall of this type of story. Monaghan, who never quite found a role that properly capitalized on her explosive breakthrough in Kiss Kiss Bang Bang four years back, is strong in the lead; to be frank, I wasn't quite sure if she could pull the role off physically (not to sound sexist, but good Lord is she a tiny wisp of a thing), but the force of her personality is plenty convincing. Her finest scene comes around the halfway mark (an open, honest conversation with Peter about why she left when she did), but many of her best moments are sans dialogue--she does wounded and steely quite well, and Mottram is wise to frequently let his camera hold on her face and study her fleeting reactions.

The plutonic relationship between Diane and her married buddy Runner (Nathan Fillion) provides occasional drama but mostly works as a vehicle for Fillion's dry comic wit and easygoing charm; he and Monaghan are quite good together, effortlessly conveying why these two like each other, why they're tempted to act on it, and why they know they can't. Bennett (seen recently in Orphan and Shorts) is a skilful young actor, though Bratt and Adams don't get much to do in support.

As it comes to close, the film can't quite manage to pull itself together to a satisfying conclusion; it tries, but the eleventh-hour crisis climax feels forced and a little out of left field. (That said, the closing scene is awfully good.) Overall, Trucker's basic beats are familiar and there's little in it we haven't seen before. But it's well-constructed and sensitively played, particularly by its tough-as-nails heroine.

Jason lives in New York. He holds an MA in Cultural Reporting and Criticism from NYU.