Back in the day when we went through periods of " undisciplined " driving...often less experienced drivers...we appointed a chief marshall for the day, usually a committee member to oversee driving standards and issue warnings...worked very well....there was often a race commentator who also kept standards up.
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Don't know whether it still applies, but at Regional and National events there was a referee on the rostrum advising drivers..this always worked well...particularly when it was Shimmy.
Driving of any kind needs to be policed..!!