I just watched Birdemic, and I've come up with a theory as to how it is actually a brilliant film.
Rod, the main guy, actually is a murderer and the whole movie is in his mind. He's such a creepy guy, it's the only way this movie makes sense.
He was following the main girl (can't remember her name), and everything that happened after he met her is all in his mind. She was creeped out by him, but he perceived it as going well. The date he had with her didn't actually go well at all, and he abducted her. Then the birds start appearing.
The birds are just a hallucination, or the way he justifies his violent acts to himself. Every time the birds show up someone dies. He killed them, and the birds are just in his imagination.
In reality, he abducted the girl and the two kids, killed the people on the bus, the couple he was with, his old friends, the kids parents, the guy who tried to steal gas. But the movie we're shown is from his perspective and "The Birds" did it...
The tree hugger got away after "The Birds" set fire to the woods, but called the police. At the end when the birds go away, he's being arrested and put on medication.
The whole movie is his explanation for what happened. The long driving scenes are put in there to account for where he was at specific times.