We do stop at red lights. There are norms about where the press can and cannot go. We have habits and we avow them as norms.
It won't do to make social grammars be only retrospective systematizations of preexisting behavioral regularities.
Wilfrid Sellars is right that norms should be seen as more than alternate axiomatic descriptions of pre-existing behavioral regularities, since norms are involved in forming a community which exists, in part, because it avows them.
(A whole school of recent Hegel interpetation extends this lesson: Robert Pippin*, Terry Pinkard, and others).
(c) David Kolb, 1 August 2001