Public property
If the roads were private property, the Amish situation would be a simple property rights issue. In a free society, a lot more things would belong to specific people or organizations, and there would be a lot less that fell under the catch-all phrase, "public property."
Individualism does not imply the right to run roughshod over everyone else. I assume you know that much about libertarianism.
Order and organization sometimes, but do not always, require government action to bring it about.
