You could ask them how they got into Perdue University. If they are smart enough to study there, they should be smart enough to read and understand cycling traffic rules/laws. Or at least use common sense to realize they are doing something dangerous and wrong.
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The Lord is merciful and gracious, slow to anger and abounding in steadfast love. - Psalm 103:8
I am a cyclist. I am not the fastest or the fittest. But I will get to where I'm going with a smile on my face.