Actually, I legit played that game on a road trip since this conversation came up with a friend right before we left (2017 timeframe). I counted and kept track.

Actually, I legit played that game on a road trip since this conversation came up with a friend right before we left (2017 timeframe). I counted and kept track. Through Colorado north bound i-25, roughly 60% were more than 1 occupant. Through Wyoming, then west bound i-80 was about 40% more than 1. Didn't do it on the return trip. Throughout east coast Florida city driving doing it every now and then (especially at traffic stops) ranges from 40-60%. Rainy days seem to be high single occupant days from what I've noticed. Sure, anecdotal, not perfectly scientific or even at a good enough scale... but I don't really believe the 10% idea. I'd love to see where their scientific data is on that.