You mean social norms, not "education". In in some cultures a disregard for these norms is sometimes referred to as a "lack of education", implying the individual's behavior is the result of bad parenting. This assumption is usually a coping mechanism, a simplistic attempt at a resolution of cultural conflict by asserting that one set of norms are better than those of their cultural antagonist. In cases of cultural conflict, where cultures with sets of incompatible norms attempt to coexist, the result is usually conflict followed by the establishment of new refined sets of norms shared cultures.

Road work signage is an issue of liability in the US, not courtesy.

Why so adamant that the two are mutually exclusive? The reason road work signage has been legislated (or socially defined) into an issue of liability is, again, due to education.