Some great inputs here. I like the learning I get to do on the forum. Two side things I thought about were 1) roads are not just paved to handle cars, they have to handle trucks, semis and other larger machinery that probably require it to handle heavier loads than just cars (though as demonstrated today, the trails have to handle some trucks too). My guess is if only cars were on roads, they would not require quite as much pavement and gravel, though I don’t know for sure. And 2) cars have a higher person-per-vehice count that bikes. I’m not sure what it is exactly, I thought I remembered it being like 1.2 persons per car (amazingly low), but I could be wrong on that. Buses certainly have a higher person-per count as road users. Not sure how this would impact your numbers, but its something to think about as most bikes are only one person per bike.