Okay, maybe your brain is wired differently, just like the brain of the designer who created the lights.
The position of the light on the car is a signal for my brain, but it takes some processing. If it's on the right side of the vehicle, my brain evaluates that to "right" and vice versa, but maybe it's a short car, like a Smart ForTwo or a Fiat 500, and I'm looking at its side, so the right-hand-side indicator is left from the "center of perceived mass", but in that case there should be another smaller light somewhere around the side-view mirror and hmmm, yeah, it's turning right. It just takes a tiny bit of processing power and a tiny bit of time.
But an arrow, boy, I've been looking at arrows all my life. They've been telling me where to go at the train station, which way to turn on Google Maps and sometimes even literally which way to turn the steering wheel, on the outside of a sharp turn. An arrow requires no additional processing and is a strong, unmistakable signal.
So what my brain sees on that Mini flashing its left indicator is something like "Car turning left, btw RIGHT".
The position of the light on the car is a signal for my brain, but it takes some processing. If it's on the right side of the vehicle, my brain evaluates that to "right" and vice versa, but maybe it's a short car, like a Smart ForTwo or a Fiat 500, and I'm looking at its side, so the right-hand-side indicator is left from the "center of perceived mass", but in that case there should be another smaller light somewhere around the side-view mirror and hmmm, yeah, it's turning right. It just takes a tiny bit of processing power and a tiny bit of time.
But an arrow, boy, I've been looking at arrows all my life. They've been telling me where to go at the train station, which way to turn on Google Maps and sometimes even literally which way to turn the steering wheel, on the outside of a sharp turn. An arrow requires no additional processing and is a strong, unmistakable signal.
So what my brain sees on that Mini flashing its left indicator is something like "Car turning left, btw RIGHT".