Engineers invented the first automatic sliding doors in 1954 and they became commercially available in 1960. But they used a mat on the floor to trigger the doors, which is definitely not the case ...

In your path: Three automatic glass exit doors that slow your progress out of the airport terminal. It feels like one door may close behind you while another may never open, trapping you in Newark ...

The next automatic door wasn’t around until 1931 but only existed in one restaurant in Connecticut. It swung open and closed to allow waiters back and forth to the kitchen.