&gt; <i>Would those signs mean much to you, or would you trust your two feet, sense of balance, and situational awareness to find the right speed? People do the same in cars.</i><p>Except people don&#x27;t have speedometers, and cars do. They are there to be used.<p>&gt; <i>A small subset of people, I believe it&#x27;s about 5%, follow the sign regardless. These people create traffic problems since they move at a different speed than the rest of traffic. I read a good article about how traffic planners are re-evaluating the idea that slow speed limits are a good thing or beneficial for safety. (...) The takeaway from the research was that if traffic planners want people to drive more slowly, then they need to create smaller, narrower roads.</i><p>Society is fixed, biology (or in this case: external conditions) is mutable. It&#x27;s a sad but I guess unavoidable outcome - since people under given conditions behave predictably like morons, it makes no sense to ask them to be responsible, so let&#x27;s redesign the roads instead.