loop (or lack thereof) update
Beel, as it turns out there is NOT a loop. I got an email update from the signal technician (who went out & checked it) who said Ladd gets a green every other cycle regardless of whether there's anyone waiting.
The reason for the every-other-cycle deal dates back to the Ladd/Lincoln/Clinton mega traffic calming project of the late 80's - it's meant to discourage through traffic in Ladd's Addition. So it's generally a good thing, albeit working against bicyclists who want to go that way.