Forward-opening doors: Even when the car is running, it can still be closed by the pressure of the airflow, which is safer and is convenient for the driver to observe backwards when reversing, so it is widely used.
Reverse opening door: If the car is not closed tightly, it may be rushed open by the oncoming airflow, so it is used less. Generally, it is only used to improve the convenience of getting on and off the car and meet the needs of welcome etiquette.
Horizontally movable door: Its advantage is that it can be fully opened even when the distance between the side wall of the body and the obstacle is small.
Lift-up door: It is widely used as the back door of cars and light buses, and also used in low cars.
Folding doors: widely used in large and medium-sized passenger cars.