Which of the following is NOT a condition under which speed limits may apply?

Speed limits are established to promote safe driving under varying conditions. In ideal conditions, where visibility is clear, weather conditions are favorable, and traffic flow is smooth, drivers are still expected to adhere to speed limits. However, in other conditions such as poor weather (like rain or snow), emergency situations (which may require speed adjustments for safety), or heavy traffic (where congestion can dictate slower speeds), these circumstances can necessitate a driver to adjust their speed to maintain safety. Thus, ideal conditions do not impose additional requirements or alterations to speed limits, making it the correct answer as the one that does not represent a condition under which speed limits may apply.