Exactly. Ideally, speed limits are an expression of policy that reflect the normative values and desires of a jurisdiction. The best case would be for us to bui

Exactly. Ideally, speed limits are an expression of policy that reflect the normative values and desires of a jurisdiction. The best case would be for us to build roadways that reinforce those values. Many roadways in the US were engineered under a set of assumptions that are incongruous with modern empirical understanding and with modern values. Wide roadways with big turning radii were thought to be safer. Turns out that encourages behaviors that are less safe for a multitude of roadway users. Similarly, there was a 20th century modernist notion that we should use the car for everything. Our bodies (everything from stress measured by cortisol levels, to obesity, to heart disease) object. The 21st century task of planners is to figure out how to retrofit a system built around monoculture into a system that can accommodate a larger aggregate number of people. Part of that is traffic calming.