Most of my life I have driven motorcycles and often people have looked right through me.
I've talked to several afterwards and they honestly never saw me, so I have always been curious about why. This doesn't apply in every situation of course but it does in many.
The real problem is that people drive a lot and arrive at their destination uninjured mostly which leads to
habituation.
They end up driving in a semi sleep state without realizing it and the primitive part of the brain scans incoming data both visual and audio for threats and wakes the reasoning part of the brain up in time to deal with it, mostly.
Very similar to hypnosis. The thinking part of their brain is elsewhere, not just the guy texting, most everyone is doing this to some extent while driving cars and light trucks.
The primitive brain can only react to actual threats and a motorcycle is not a threat to a person in an auto or truck. Because of this the primitive brain does not awaken the reasoning brain when the bike comes into view. This is why people see right through you. The exception is if their brain is in reasoning mode for some other reason and hasn't shifted back to auto yet when they look your way. But if they are in auto mode when they see you, the sensor that wakes them, (primitive brain) does not bring them to a full state of consciousness where they see you and recognize that you are there when they look your way. This sort of science is what is behind the governments push to autonomous cars which react to whatever they are programed to react to.
To put it in the most simple terms, if someone in a car sees you when you are riding a motorcycle it is most likely an accident that they do.
Headlight modulators work because flashing lights are used by the police and emergency vehicles who are often assisted by the police. The brain associates the police with emotional pain. Being ticketed is always a emotionally painful experience and registers as an actual threat.
People also see police motorcycles for the above reason. The wife had a HD police bike for 30yrs. The first years she owned it she removed the blue lights and rode it as it came, cop paint and all. Her helmet was the same one issued to most police. At that point she did a lot of long distance touring. She'd spent most of her trip passing long lines of cars that slowed down as soon as she came into sight thinking she was a cop. They had no problem seeing her from very far off. After a wreck she re-painted the bike so it no longer looked like a police bike from a distance and bought a different helmet and the problem stopped. This
book talks about the cop bike effect.
Our sidecar bike produces the same results so far. The silhouette of a sidecar is very unusual and it causes their brain to snap their attention to us. This because the primitive brain also sees things that it doesn't recognize as threats and wakes the conscious brain for a final decision. People that you can tell are about to pull out in front of you, see you and wave instead. This wouldn't work if sidecars were everywhere. But so far it seems to work mostly.
Our latest sidecar bike came with a headlight modulator and people see it farther off and at higher speeds, especially when the modulator is turned to the setting closest to a police car or emergency vehicle.
Next time you get run over by someone who looked right at you, this is probably why.