I live in a town that's a suburb of Portland, Or with the entire metro area of 1 million or so. There are plenty of flats as well as hills if you want them. I consider myself a leisure rider. I like to go out and see & smell new places. According to my Cateye Strada my average speed ranges from 10-14 mph. I have ridden about 197 miles in the last 4 weeks or so. My max. speed, usually down a hill is about 18-21 mph, although I can go up to about 16 mph on flats if I want. I find that when I ride faster I have to pay more attention, and it takes away from my enjoying the scenery and looking around. I have been riding in the past 6 months my new Trek FX 7.3 FX. I have ridden more in the past 6 months than the entire previous 25 years. This is due to having the appropriate bike, and one that I really enjoy. So, my typical rides involve riding to a destination, maybe 5-10 miles away, having a coffee or lunch, then riding home.
So that's it. Hope that helps. I find that motivation is a fickle friend-it comes and it goes, so I don't rely on it to keep me active. I just do it.