All other road users are, at a certain level, considered "not human" by the brain, just as when you're in a crowded shopping centre, most of the people are "things" not other people. The brain can not truly consider, at the time, in a busy place, that everyone else about you is a person.
The difference with people on bikes, rather than in other cars, is that smaller collisions, that occur often, have a far more drastic effect.
It's why so many people try to make a real effort to look others in the eye when cycling on the roads.
Make people behind the wheel of a vehicle you're close to see you as a person, not just another vehicle. Get their attention, don't just be background noise.
Sometimes this annoys people driving, such as getting front and centre in a queue, but do it. Make them register you as a person, not an object on a crowded street.