If you know what the Taiwanese have to do and learn in order to get a license here you’ll understand right away why they participate in traffic the way they do.
Add to that their ignorance, self centeredness and selfishness then your understanding is complete.
That’s a pretty harsh generalisation. For me the issues with driving here are primarily due to a driving test that isn’t fit for purpose. The MOTC are in the process of improving this. It will of course take time.
In some ways the driving culture is better than ‘back home’. For example, horns are used here to warn other drivers - not to show aggression. OK, admittedly the warning is often about doing something daft such as running a red light.
Really? You sure about that? 
I’ve been witness to plenty of aggression by way of horn honking, tailgating, cutting off, yelling, baseball bats, golf clubs and tire irons. Road rage here is very real, very common and very dangerous.
Of course road rage is in every culture. I haven’t found it more prevalent in over ten years driving here.
Where I come from, we are angry drivers that drive fast in the lines. Here, they smile before they pull out in front of you without stopping at the stop sign. Lines on the road are just a suggestion and other objects on the road such as cars are obstacles to go around. And I love the u-turn thing in the middle of the road. I can’t do that at home and it is really fun to do here.
Outside of Taipei being able to park wherever you please is also a bonus. Need something from a convenience store? Just pull over.
Put on your flashing lights, too. Just for fun! and to remind everyone that you are a hazard!
So it’s illegal to flash your high beams as a means of communication reminding the oncoming car that they may have forgotten their high beams are on, yet not illegal for them to be driving with their high beams on?
That’s ok, I don’t flash them. I just turn my high beams on until they turn theirs off.
No one cares about traffic rules and they’r going to shit about not backing in?
Yesterday I got this a**hole and his girlfriend jet out of 7-11 because he parked his car conveniently at the bus stop in front, I flagged down two coppers on a scooter and they paid attention to my need!
Today 7pm on Freeway 3. A car overtaking me, without lights on. Another one slalom driving across three lanes in dense traffic, no room for error. Oh, another one driving about 80km/h in the middle lane wheels going across the line to the left, then to the right, then to the left, drunk or texting, or both. Truck with bright colorful lights all across my rear window, almost kissing my back, then overtaking me on the right side. All in a span of half an hour or so. Made it home safely. Knock on wood.
Sounds like every other day for me! 
Just this morning there was this ‘bottled water’ truck, the driver conveniently covered his license plate and the painted license plate number on the back of his truck with a push cart.
In most of Europe that would conclude in a fine.
In most of anywhere, everything people do here would conclude in a fine.
Cracks me up when I see a scooter with a basket on the front…completely blocking the headlight, especially when they have a big bag in the basket.
Welcome to Taiwan. In terms of driving, this is the jungle.
Watch it bring you to your
Knees, knees
I wanna watch you bleed!
(Unfortunately, literally sometimes).
Don’t try to explain the behavior of local drivers, there’s no answer to “why?” question. "This is their culture"©®™. Just follow the flow and try to survive.
I find that if you car is loud enough , they move eventually. 
https://www.youtube.com/watch?v=tX5kR2FZG94
Fei Xiaotong, China’s first sociologist, described Chinese people’s moral and ethical characteristics in his book, From the Soil, in the middle of the last century. He pointed out that selfishness is the most serious shortcoming of the Chinese. “When we think of selfishness, we think of the proverb ‘Each person should sweep the snow from his own doorsteps and should not fret about the frost on his neighbour’s roof,’” wrote Fei. He offered the example of how the Chinese of that period threw rubbish out of their windows without the slightest public concern. Things are much the same today.
https://www.theguardian.com/commentisfree/2011/oct/22/china-nation-cold-hearts