Originally Posted by PatrickGSR94

Do you use a mirror? When I turn left with traffic behind, I use a combination of my helmet mirror and head turns, while my hand is out, to make sure they're not about to pull some bonehead move like trying to pass me on my left as I'm preparing to turn left. Seems to work pretty well. Usually you can tell if a motorist sees you or not. If they're moving to the left turn lane behind you, especially with a turn signal on, you could also let them go by in the left turn lane while you're still in the left thru lane, and then get into the turn lane behind them.

Just some thoughts and suggestions you might try out in the future, even though you said you may not go that way again.