The answer is regulatory signs. The term regulatory sign defines a range of
signs that are used to specify or emphasize traffic
laws, rules or requirements which apply either at all times or at
indicated times or places upon a street or highway, the neglect of
which may constitute a violation, or signs in general that regulate public
behavior in places open to the public. Traffic signs are the best
example for this kind of signs. It is intended to
instruct road users on what they must or should do (or not do) under a certain
set of conditions. Other types may be signs positioned on streets and in
parking lots having to do with parking, signs in public parks and on beaches or
on or in architectural facilities prohibiting specific types of activities.
