How do bus doors open at the same time?

The driver pushes one button. Both open because one button tells them. You hear a soft hiss. The doors swing like two hands.

Most bus doors are joined to one control by the driver. When the driver presses a button or moves a handle, air or a small motor pushes both doors at once. So they start moving together. It is like one light switch turning on two lamps in the same room.

Bus doors open together because the driver’s switch sends one signal to both door parts at the same time. Many buses use pneumatics, which means squeezed air does the pushing. The air goes into little pushers called cylinders, and they move the door arms. Some buses use electric motors instead. Fun fact: the “pssshh” sound is often air rushing out after it has helped move the doors.