Traffic in Thailand is actually very safe, if you exclude motorbikes. Motorbikes contribute to 80% to 90% of fatalities. If you exclude motorbike fatalities Thailand would be be among the safest nations in the world. Most European countries have a very small motorbike community and they are mostly pretty safe drivers.
In Thailand most vehicles are motorbikes. There seems to be no enforcement of any laws regarding motorbikes. Helmets are not used, in all neighboring countries you hardly ever see anyone driving a motorbike without a helmet. Pretty much all three wheel motorbikes, like food carts, are illegal. To have a license to to drive a motorbike seems optional, unless you are a tourist. By law you can only be two persons on a motorbike but you frequently see many more, especially if you are near a school where 3 to 4 students, without helmets, arrive without any intervention from the school, police or parents. There are also numerous motorbike delivery drivers who take all sorts of illegal and dangerous shortcuts.
If the police could find the time to enforce the law regarding motorbikes the traffic fatalities in Thailand could easily be cut by 80%