If you want to motivate people to action, frame it in terms of the property damage they’ll experience to their car when it hits a child. We’ve already seen how far the American public is willing to go for children’s lives, and it’s not very far at all.
That’s a cool solution! I guess if trunk or treat is the only event a place can do it’s better than nothing but I’m glad to hear you got creative about supporting the old ways :)