Meaning 1: Dating within a small friend group or family, and ending up with the first person you dated again.
Meaning 2: how badly the road construction in Orillia obstructs the traffic.
example 1: Joe Dirt dated all four of the Reed sisters starting with Frankie. After he went through 'em all he got back together with Frankie! He made the full Orillia roundabout!
example 2: How do you like the new Orillia roundabout at the end of the street there? Sure has cut the traffic down, everyone seems to be avoiding it.