Comedy-drama. Starring Britney Spears. Directed by Tamra Davis. (PG-13. 105 minutes. At Bay Area theaters.)

There's no point in pretending "Crossroads" is worse than it is. As pop- singing actresses go, Britney Spears is not an embarrassment (like Madonna) and not yet an actress (like Mandy Moore). And the movie is fascinating in its own strange way, not as entertainment but as a cultural document.

Go into any supermarket, and there's Britney, smiling from the cover of at least two magazines. Adults might forget her between TV commercials, but she has been, for years, whispering nonstop into preteen and pubescent ears. "Crossroads" is a chance to eavesdrop on what she's been saying.

She plays Lucy, a virginal high school valedictorian who loves to sing. Her father (Dan Aykroyd) wants her to become a doctor, but she's conflicted. She feels she's just not a doctor, and not yet a singer, either.

There has always been a disconnect between Spears' offstage and onstage personae. When not singing, she cultivates the image of a scantily clad but chaste young lady. But onstage she acts like every sailor's pal when the fleet's in.

At a pop concert, this disparity can work. Music blurs edges, elevates personality and pushes everything into the dimension of fantasy. But a movie makes everything literal. So in "Crossroads" we home in on a wholesome young thing, then see her bumping, grinding and groaning as though in a state of arousal. What is this about?

Lucy and two of her old friends hook up with a young man and drive cross- country to Hollywood. Their driver (Anson Mount) has a prison record for violating the Mann Act. So now he's taking three underage girls over multiple state lines. Give the man credit. He finds a crime he likes, and he sticks with it.

Throughout "Crossroads," director Tamra Davis finds ways to show Spears off.

She appears in her underwear twice in the first 15 minutes and carts out her trademark zany look -- eyes crossed, tongue out. She sings "I Love Rock and Roll" in a karaoke bar and never stops giving us renditions of "I'm Not a Girl,

Not Yet a Woman," which is the worst kind of bad song. Bad and catchy.

In the end, "Crossroads" is a lot like Spears herself. It cultivates not the illusion of wholesomeness, since no one's buying it, but the pretense of it. Yet examine the movie's message, and it's pretty insidious. We see Britney taking off on a cross-country trip without her father's permission, hanging up on Dad when he tells her to come home, and sharing her bed with an ex-con, who looks as if he's 30. And the movie doesn't present this as naughty or even adventurous.

Rather, it presents this as the behavior of a nice girl who's a little on the nerdy, conservative side. If this is a nice girl, this is not good news, though not yet a disaster.

Advisory: This film contains sexual situations and coarse language.

-- Mick LaSalle