You have the trigger delay (I'm sure you have a different name for it) set too short on this detector loop. What it's set to do is, after a detect to give left turns from Barton onto Plymouth, detect a 'long-enough' gap in traffic, and change the green left turn signal back to red. The problem is the 'long-enough' part, which must be something miniscule in this case. Because I'm biking to work, and the loop doesn't detect me, if anyone stays back from me at all, everyone behind them gets stuck at another red light. This morning eight people got stuck for a second red light because a bus driver hung too far back. The light is unnecessarily delaying people because of a three or four second shortage in the program for that controller.