Proposed Canon
Roads are a Terrain Type in Erfworld.
Roads offer movement free of movement penalties.
Roads can be built or destroyed by some kind of engineer unit.
Roads' lack of penalties may only count when entering and leaving the hex from certain sides.
If plains are the 'base' terrain and offer no movement penalty, roads may offer a bonus.
Roads may offer a 'trade' or 'commerce' bonus to the income of cities they connect to.