Marshal
Marshals are the trackside volunteers who wave the flags, clear debris and reach an incident before anyone else.
They are almost entirely unpaid. Every flag a driver sees is being waved by one, and every stranded car recovered under a yellow is being recovered by a group of them standing metres from cars at racing speed.
It is the reason yellow-flag infringements are treated as seriously as they are: the rule is not protecting an abstraction, it is protecting the people standing at the edge of the track.