Crash is an excellent example of horizontal storytelling, for both what works and what doesn't. Horizontal storytelling is everything happening at the same time. Vertical, or linear, storytelling is what happens next. Horizontal storytelling works primarily by comparison. Vertical storytelling shows the development of one thing, usually a central character.
Horizontal storytelling causes all kinds of problems, which is why it is very rare. First, there's so much cross-cutting between approximately equal events in time that narrative drive stops.
Second, you have to present so many characters that you can't explore any of them in much depth.
Third, you have to rely too much on coincidence to bring characters together and give the story some shape, some vertical development. Otherwise the horizontal spirals out to infinity.
Fourth, you often can't find a way to end the story other than to just stop. When one story event doesn't follow necessarily from another, there is no 'right' final scene, just the last thing that happened in time.
To deal with these problems, the first thing the horizontal storyteller has to do is come up with an organizing principle, an underlying unifier that gives a logic to the unfolding. Writers Paul Haggis and Bobby Moresco use a subject, and this immediately causes problems of its own.
The first problem these writers encounter by using a subject is that the one they choose, racism, is likely to blow up in their face. Any story that tries to talk about racism will appear to many in the audience to be racist. If the strategy is to show characters believing the stereotypes of the various races in order to reverse or upset them, the author may seem to believe the stereotypes himself.
A second problem the writers encounter by using a social subject as their organizing principle is that the story feels heavy-handed from the opening scene. When you are writing an extremely horizontal story, you have to do many more scenes of racial set-up, so the first third at least of the movie is in grave danger of infuriating the audience into giving up.
Crash shows all of these problems of the horizontal form at the beginning. But Haggis and Moresco know how to use the benefits of the form as well. For example, they know that the horizontal story, while running the risk of superficiality, allows them to set up a giant moral accounting system. Each character, with his unique moral flaw, gets his poetic justice through the help of every other character. This is cosmic, Twilight Zone accounting, like Vertigo, but on a much grander scale.
With the thematic heavy-handedness in the beginning of the story, Crash's grand accounting program may feel a bit schematic. The more you push the horizontal, the more you stretch the skin and bones of the organic body to its breaking point, the more you show the contrivance, the mechanism, of the author underneath.
But about a third of the way into this film, the benefits of the horizontal story form start to kick in. Much of the pleasure of the grand accounting comes in the pleasures of the comparisons, of who will show up to give a character his comeuppance. This is the pleasure of the grand story weave. It requires top plotting ability, and these writers have it.
The story weave, in the form of reveals and reversals, is also what saves the film from being too morally top-heavy. Having done the difficult set-up work, the film can run a series of great flips: the car on fire, the little girl, the guy releasing the slaves, etc.
Another benefit of the horizontal form is that you can set the firing pins to go off for all the characters about the same time, so you can give a succession of hard shots to the head and body of the audience. By the end of the film, these shots come with terrific intensity.
There is one more bonus to the horizontal story, and it's a thematic one. This complex social weave is the story equivalent of a Breughel painting, for example, the large canvas of the village in winter where pockets of individuals and groups go about their daily affairs, largely unaware of each other, but as part of a diverse community where the hidden hand of mutual benefit is always working. In Crash, the characters are divided off from one another by their city and their cars. But in the rare moments of connection, these people, each with the same moral blind spot, show their essential humanity.
