First of all, the semicircular canal in the inner ear and the two saccular structures in front of the semicircular canal are gas balanced. When riding a car, people are constantly shaking (the shaking range may be small, such as a train). In order to keep the inner ear nerve in a constant state of balance, it needs to send out balance instructions frequently, which makes people very tired and easy to fall asleep.
On the other hand, in order to suppress this frequent regulation, the body produces a stress reaction, just like other creatures' self-protection, such as suspended animation, which will make people fall asleep. When two sides * * * the result of the same action.
Because there is no ventilation in the car, it is difficult for the outside air to enter even if the window is opened. Besides, there are many people in the car, and CO2 increases, so I feel sleepy.
If you are not too tired at work, you should adjust your daily eating habits, go to bed early and get up early, exercise properly when you are free, and adjust your life to a normal state.
In addition, the position of the car is fixed, there is no place to walk, and it is easy to get tired if you keep a relatively fixed posture for a long time;
Fourth, there is no communication with people or doing other things, no problems that need your brain to think, no stimulation to the brain, and the cerebral cortex is in a relaxed state.
I feel sleepy when I take the bus. Later, I even went to sleep as soon as I got on the bus. I use the bus as a rest time to accumulate strength, so don't worry too much.