Motorcycle fatality rates have been trending upwards, not downwards[1]. Brake lights on helmets may illuminate one of the culprits: An ever increasing number of American trucks with poor visibility. Sitting on a bike, you're even shorter than a pedestrian and more likely to be completely out of sight. Perhaps its time to start regulating for better visibility, as Europe has done.
[1]https://www.iii.org/fact-statistic/facts-statistics-motorcyc...