Where did "Lollipop men" go from F1?
In the old days the Formula 1 spectators were familiar with "Lollipop men" that signalled when drivers could leave the pits. What happened to them?
The lollipop men were replaced by lights that show what should be done. In addition to safety, it's also a matter of proggress. A single person will have difficulty to make out a full picture of the status of the pit stop. Now the information is relayed from different signals such as bolt guns and the green light is shown automatically once everything is good to go.