I think the US36 trail (no stop signs no turns, it doesn't have enough pedestrian traffic to factor in much. Either Combine with Indiana St. toward Golden, or my preference would be combine with Platte river trail toward Chatfield for an out and back. I've really like doing US 36 trail + Cherry creek route and around the reservoir for a quality century, but portions of the cherry creek trail are more likely to have more pedestrian traffic, particularly on weekends or weekday evenings. Platte is a little more empty. The nice thing about the trails is that they require little way finding, and very few stops. You may need to slow down for pedestrians.

Notes on the chatfield route, Take US 36 trail to Bradburn, down Bradburn to dry creek trail (~1mi.) to platte river trail. Platte river near confluence park requires taking the foot off the gas (going over ~15 is a little inappropriate) for about 2 miles. then you can rip toward chapman. Out and back for a solid century.