I have some photos that might help you with that (of guys all lit up in their gear for a night ride)
Is it dark when the meeting is held? A "field trip" to the sidewalk or parking lot would let you illustrate your points under real-world conditions (visibility-reducing overhead lights) and relevant distances (at 40 mph, a car is traveling about 60 ft/sec). Plus you'd burn up some extra time getting to and from![]()