There will be people who will think ''Crash" is the most important film they have seen in years, and good for them. Whatever makes sense of this vale of tears through which we travel in air-conditioned isolation at 75 miles per hour.
Permit others to be less convinced. ''Crash" is one of those multi-character, something-is-rotten-in-Los Angeles barnburners that grab you by the lapels and try desperately to shake you up. It's more artful than ''Grand Canyon," less artsy than ''Magnolia" (LA gets dusted with snow instead of frogs), and much less of a mess than ''Falling Down." (Michael Douglas as an angry nerd in horn-rim glasses, remember?) It also features some hellaciously fine acting and at least one scene that will stick with me for years.
But its characters come straight from the assembly line of screenwriting archetypes, and too often they act in ways that archetypes, rather than human beings, do. You can feel its creator shuttling them here and there on the grid of greater LA, pausing portentously between each move.
Since that creator is director Paul Haggis, a longtime TV writer who grabbed the gold ring last year by writing the script for Clint Eastwood's ''Million Dollar Baby," I guess he's earned the right to make a big statement. But, boy, does he want you to know it.
Traffic and race are the twin obsessions of everyone in ''Crash" -- the latter especially sends the characters into conniptions. Two young African-Americans, Peter (Larenz Tate) and Anthony (Chris Bridges, a.k.a. the rapper Ludacris), stroll down a busy boulevard and watch the rich Caucasians flinch. Anthony, the angry street-corner philosopher, muses, ''We're the only black people, surrounded by a sea of overcaffeinated white people -- why aren't we the ones scared?"
His friend has an interesting response, which I won't spoil, but it's fairly shameful, and it underscores that while Haggis thinks he's exploding racial clichés, he's really just rearranging ones we already live with.
Elsewhere in ''Crash," a rising young district attorney (Brendan Fraser) gets carjacked and despairs that the perpetrators had to be black (now he'll lose either the African-American vote or the law-and-order vote). His pampered wife (Sandra Bullock, who's barely in the movie, no matter what the trailers imply) retreats behind a wall of privileged paranoia, taking it out on Daniel (Michael Pena), a Mexican locksmith with jailhouse tattoos.
Daniel, of course, is a sweet-natured husband and father struggling to get his family to a neighborhood where the gunfire doesn't pop all night. He also struggles to keep his cool when dealing with Farhad (Shaun Toub), an Iranian shopkeeper who understands English only as it suits him and is so convinced the world is ripping him off that he buys a gun against the wishes of his upscale daughter (Bahar Soomekh).
Most central to the movie's harrowing vision are two LAPD cops, the venomously racist Ryan (Matt Dillon) and the good-hearted rookie Hanson (Ryan Phillippe). We first meet them as Ryan decides to pull over a Lincoln Navigator in which buppie film director Cameron (Terrence Howard) and his chic wife Christine (Thandie Newton) are engaged in a bit of post-awards-banquet horseplay.
The scene gets ugly and Dillon turns Ryan into a genuinely hateful man -- Haggis pushes his loathesomeness into our face. So it's a shock when ''Crash" humanizes the cop later in the game. That becomes the film's modus operandi: The director dares us to assume we know these people, and then neatly offers conflicting evidence.
Rather too neatly in places, and in others most unconvincingly. After Cameron is further humiliated on a film set by his producer (Tony Danza), he embarks on a course of action that simply makes no sense. Characters intersect with one another in what can only be called Screenwriter's Coincidence: By the time the young cop picks up Tate's Peter, I was sure everyone in this overcrowded film had been randomly introduced to everyone else. (I was wrong -- the shopkeeper's daughter unexpectedly shows up at the very end.)
Against that, Haggis pulls off some powerful scenes, particularly the sequence in which a rescue from a flaming car is intercut with the shopkeeper finally being pushed over the edge; the soundtrack music, which could have been wham-bam thriller stuff, is instead a lovely and liquid Arabic track by the American rai singer Shani Rigsbee.
Also quite wonderful is Don Cheadle's performance as Graham, the police detective who connects the story's tangents and who becomes the film's weary heart. You get a sense of LA's racial gridlock in the scene in which Graham gets a dose of realpolitik from the district attorney's political adviser (a brilliant William Fichtner).
At the same time, the cards are stacked against Graham in ways that are all too ''ironic." Haggis still has the mind, if not the soul, of a TV writer -- I don't say that to be unkind (I can't wait to see what he does next) but to insist that real life does not fall apart quite this tidily. His agony may be real, but his perspective is still that of a man looking down from the Hollywood Hills, seeing chess pieces rather than people.
Ty Burr can be reached at email@example.com.