Development and Validation of Speed Kidney, a New Traffic-Calming Device

Traffic calming has been widely applied to urban areas in recent decades to moderate speed and traffic volume. Because most measures used are physical, a vehicle must modify its path and speed. A benefit of traffic calming is improved safety from speed reduction and traffic volume reduction. However, traffic calming has disadvantages, such as emergency response delays, traffic diversion, noise, vibrations, damage to vehicles, and discomfort. Common traffic-calming devices do not consider discomfort for drivers who achieve an appropriate calmed and safe speed. Consequently, it was necessary to develop a new traffic-calming device to moderate speed and to minimize the disadvantages of the previous devices. The Highway Engineering Research Group of the Polytechnic University of Valencia, Spain, has invented, designed, and developed a new traffic-calming device, Speed Kidney. This paper provides the objectives of the Speed Kidney, a description of the new traffic-calming device, and its geometric design. The technological development of the device is described, as are the main results from preliminary tests, implementation on a campus street, and implementation on a controlled test track. Implementation criteria are also given. The Speed Kidney is a functional, feasible, sustainable, and safe solution for traffic calming.