I first wrote about the concept of the Speed Kidney in 2012. Basically, it’s three speed humps that are parallel to the traveled way that are curved as a chicane per the diagram. This doesn’t necessarily reduce the average speed very much, but they reduce the number of vehicles driving significantly faster than the design speed. I like the idea of getting rid of the outlier speeders and clustering traffic at the posted speed limit.
Professor Garcia recently put together a ten minute video that updates the research and covers the results from live installations. I encourage you to check it out. I’d really like to see more Speed Kidney’s installed. Please let me know if you know of any installations outside of Spain.