While we did not stop to hike we did do a family drive down the parkway. We saw many, many deer alongside the road (and sometimes on the road). The speed limiit is 35, and I would say that speed is optomistic, so plan lots of time. The facilities on the parkway close at 5pm, so if you need a general store or gas station do not expect them open late!
One more tip: go on a sunny day and do not drive it on a foggy day. My in-laws drove it on a foggy day and found it took forever.