Mental Speed Bumps: A Classic Revisited
An engineering consultant once told me that signs, speed bumps, and retaining walls are examples of failures in design. If the design is right, those things are not needed.
The US-23/Lee Road round-about traffic controls are an example of design failure. Not only is there a mind bending number of directional signs and pavement markings, but the control devices are different in each of the round-abouts. To navigate them safely, the best path is to ignore the controls, slow down, and watch the other drivers. That is a mental speed bump.
David Engwicht, a “social inventor” in Australia, wrote Mental Speed Bumps. The Smarter Way to Tame Trafficin 2005, while Hans Monderman, a traffic engineer, was in the Netherlands discovering a radical new way to tame neighborhood traffic: don’t.
The basic idea is that removing all traffic signs, speed bumps, line markings and traffic lights results in reduced traffic speed and greater safety. The lack of traffic controls creates “mental speed bumps.”
“Shared roads” or “complete streets” are now mainstream applications of the social contract we already apply at places like four way stops. These purposely mix user types within the overall transportation system. Another example of shared use of space is the holiday shopping rush at the regional mall. A flood of vehicles shares an enormous parking area with hoards of shoppers rushing in and out of the mall. The traffic flow is managed by the interaction between the pedestrians and the drivers rather than by traffic cops or signals, or zillions of directional signs.
Engwicht’s small volume describes the safety paradox, the idea that creating intrigue and uncertainty makes streets safer. That flies in the face of the conventional idea that predictability increases safety. But predictability leads to increased speed and a lower level of concentration on the part of drivers, cyclists and pedestrians. Add that to distractions like talking on a cell phone, text messaging, listening to music on an iPod, etc. etc. and people are not in the moment, are not aware of or truly experiencing their environment, and are essentially on auto pilot, or as dad would say, “cruisin’ for a brusin’”!
This small volume is “a practical, down-to-earth guide for residents, parents, health professionals, city planners and anyone interested in creating more livable streets.”