The side roads will remain private: does that mean ATVs, quads, scooters, etc. can be used on those roads?
Yes, it does. The side roads remain private. Look at them as an extension of our driveways. The arteries, on the other hand, are simply getting too much traffic, and too unsafe for kids to play. This conversion to public on the arteries may be a really ideal split between private and public road ownership.
