I thought "Traffic" was a pretty decent movie. It tried to do a lot with one topic, and in some ways, it really executed its point well, and in others, because it was trying to do so much, it glossed over getting into any sort of depth with any one character or plot line. This made it harder to be as much about human relationships, and just went with its theme more than anything else.
The first half seemed stronger than the second to me. The set up was pretty strong, and the less it had to do with the specific relationships, the better it was. When we first saw the government official trying to follow through with his war on drugs, it was all pretty believable and the plot line drew the audience in.
Some parts that I thought were less realistic and that drew me out of the plot line were when Catherine Zeta Jones, after not having any idea whatsoever that her husband was a drug lord, suddenly was offering a "Mexican" (Benjamin whatever is hardly Latino) bribe and trying to get cops killed when the base for her character was that she had no idea about any of the illegal dealings of her husband.
The teenage girl with drug issues was way too over the top. This can be a tendency with American movies, the default mode is to go way over the top, ie a teenage girl from a repressed conservative background starts doing crack every time we see her and prostituting herself. I liked the idea of the irony of the daughter of a purveyor of the war on drugs being a girl who does drugs, as that's a common aspect of adolescence. But I thought that her being so over the top was not only unrealistic, but also equated drug use with turning into a crackhead prostitute, which is most often not the case.
Benicio del Torro I thought was one of the strongest characters and strongest actors. I liked his plot line, because it truly emphasized how corrupt the Mexican government and law enforcement is, which is a very topical concept right now, as Mexico is currently on the verge of being completely run by drug lords. In that respect, this was a very timely movie to watch.