There have never been any studies to support the contention that neck collars are effective in at reducing injuries in karting. There have also never been any studies to show that that don’t work either. CIK in Europe has not required them for years. Stars is just following the international rules that don’t require neck collars. This year at the SuperNats, SKUSA dropped the requirement for the SP class as it was being run under international rules.
Since karting injuries are so rare, particularly when compared to other forms of motor sports, I think the improved abilities of the driver to be aware of his/hers surrounding’s out weigh the questionable value in the event of an accident. If the improved ability of the driver to see and hear avoids an incident, I think its better to make the use optional. Prevention of accidents should be our first consideration in safety.