I have no idea if anyone knows which are the most popular running routes in the country, but I would like to put forward a suggestion, and see if anyone can beat it ?
I am going with the Tower Bridge - Canary Wharf Thames path. I have run this route for years , on every day of the week....mornings, afternoons, evenings,throughout the year and it is always busy with runners. Often, there are so many runners it can feel like an organised event. Anyway, a few times I have counted the number of runners I saw on a run (9.7km Canary Wharf to Tower Bridge return, usually lunchtime) and it was easily over 100.
I think the geography of linking two huge business districts (105k workers in the Wharf and 165k in the City) with a river and dockland path make this a contender. But i'm sure there must be others, I just don't know?