Confusion in understanding control system?
Both, the automatic washing machine and the traffic signal system are open-loop for the same reason the website mentions for the home heating system.


  An open-loop system usually has a timer which instructs the system to switch on the furnace for some time and then switch it off.


The Washing machine uses a timer to turn on and turn off washing and drying without measuring how washed or dried the clothes are.

The traffic light uses timers to switch lights without measuring how many cars are actually on the road.