Living in Canada you tend to see alot of wildlife on the roads at night in most western provinces, especially back roads. This tip has saved my and many other lives, if you see an animal on the road, immediately TURN OFF YOUR LIGHTS.
This only has to be for brief moment as it will break the hypnotizing effects of the lights. This advice has allowed me to miss more than a few deer and a family of mountain goats in Banff National Park.
Once the lights go out all they hear is a big thing rushing towards them and they scatter. Now of course nothing is 100% but after telling a friend about this trick, I was awoken on one trip as she slammed on the brakes, just to see her turn the lights back on and 5 little goat butts running off the road. We passed them still going about 80 KM/h but they were already on the side of the road tearing through the ditch on their way to safety.
Hopefully this can help save some deer. :P