It depends. Locally, within the Annapolis Valley, if I am going to some kind of appointment, I will take the "big highway" on the way there, and then take the old scenic road coming back. (The "big highway" is just a two-lane road with half-width shoulders, way too many rim-killing potholes, and a 100 km/h speed limit.) If the purpose of the trip is just a pleasant Sunday drive, I'll take the old road both ways, and maybe making it a loop to see more scenery. The car gets much better fuel economy at 80 km/h than it does at 100.
If I was going into Halifax, which I haven't done for years and I avoid whenever possible, I take the big highway both ways, just to get it over with. In that direction, it is more like a freeway.