First scene JUST STOP THE CAR!

That was my first thought too. If you can't see, maybe stop and pull over and figure out the wipers, not keep speeding along.

Wow, so much time passed with no explanations given.

Well, here's mine. I had the same reaction as you when I saw it on Showtime. I wasn't even planning on watching the movie, and the stupidity of the driver's action turned me off. I almost changed channel after the opening scene because nobody keeps driving after they hit a deer, especially if their vision is impaired.

But the scene makes more sense after the movie. The simple explanation is the family was killed on impact with the deer, so really her scene was much like everyone else's—only shorter.

The movie turned out to be cleverer than I took it for (especially considering that opening scene), but being clever only works if the audience catches on. While there is an explanation for why she kept driving, it does the movie no good if you lose the audience (as was evident with you and almost with me). So I'd say the filmmakers failed in that regard.

Actually, they could have kept the clever tie-ins and foreshadowing if the driver stopped like any other human being. There was nothing to be gained by having the car continue driving. I suppose they were trying to show us that something was wrong, but it was too early for that. It just looked like a hack job.