Ben Affleck is an amoral and strangely incompetent hotshot lawyer who, one busy morning when on his way to court (where he's finagling a deal for his bosses to wrest the deeds to a dead benefactor's multi-million-dollar charitable trust from the deceased's granddaughter), scrapes his car against that of Samuel L. Jackson, an honest but short-tempered insurance salesman who is also on his way to court, to fight to keep his wife from taking his two young sons away from him.
Affleck bolts, Jackson discovers that Affleck stupidly left some important court documents behind, then he misses his appointment and loses his family somehow, and decides to get revenge by holding the documents hostage. Affleck gets angry in return, and what you have is one long day of protracted road rage between the two.
Changing Lanes starts off promisingly: Michell's visual style, albeit one stolen from Michael Mann, provides strong support for a fairly compelling "what would you do?" scenario. And the two stars at first seem well-suited to their roles, as does the rest of the cast (including a very scary Sydney Pollack as Affleck's intimidating boss/father-in-law). But the script (by "Chap" Taylor, assisted by Michael Tolkin) tries to cram in too much, in every sense: the story takes place over one day, but the arc of the behavior and realizations of these two men is too huge. You have good men turning evil, then discovering the error of their ways, played out in a nearly epic urban battle, all in less than 24 hours.
There is also far too much mumbo-jumbo about ethics and morals (not to mention some useless blather about forgiveness: the story even takes place on Good Friday, and there's even a scene where Affleck wanders into a confession booth!). The script has an annoyingly self-congratulatory air about it, as if Taylor really believes that he is giving us mere mortals some profound moral insight into the meaning of redemption. Changing Lanes, however, isn't nearly as deep or as troubling as it tries to be.
It's also hard to really like either of these men. They are supposed to be "flawed but essentially good" individuals, but they wind up a couple of overreacting cartoons. And, of course, Affleck once more proves himself to be a weak and ineffectual actor. He even bungles a key scene - and shame on Michell for letting him - wherein he's convincing one of Jackson's long-term acquaintances that Jackson has become a criminal: as a successful attorney, he should sound absolutely convincing. Instead, he rants like a madman. And yet the woman believes this complete stranger over her trusted friend Jackson, and calls the cops on him when he next shows up. Ridiculous.
Changing Lanes is a self-serious bit of cinematic flatulence that you can merrily avoid.