I experience quite the anomaly every week. We have a stretch of road that's approximately 18 miles. Beginning at dusk, sometimes earlier, and going into the wee hours of the morning, you can't count the deer grazing on the side of the road. They are literally thick as flies. However, they rarely raise their head when a car passes. In fact, most continue to eat as if the cars were just other animals grazing. They accept the traffic as part of their normal habitat. It's quite strange.
That said, one will occasionally cross the road. In the 6 years we've lived here, I've seen 1 or 2 standing in the median (divided 4 lane highway) and every once in awhile I'll hear of someone hitting one, but it's extremely rare considering the deer are there every night 365 days a year.