B'lieve it or not, though I'm not THAT old ("just" 56) I actually got my license back when only the newest or fanciest cars had blinker signals. There were still lots of cars out on the road with "flipper" signals (a reflecting flag that would swing out on one side of the car or the other, depending on which way you flipped a signal lever) or no signals at all. Back then we all had to learn the left hand signals. After all, in a car it doesn't help much to stretch out your right hand. But I guess they don't require those any more for drivers license tests. So the biggest baddest drivers on the road, kids in Jeeps and Humvies who might not even care when they do see you signal, probably wouldn't know what you meant by bending your left arm upwards from the elbow. I think I may try both signals, first one then the other. I go slow enough to have time
But it's probably only the right hand signal folks behind me understand. Maybe better to just point where I'm going and not confuse folks.