Detecting the Differences between Speed Control Bumps and Humps In terms of Speed Reduction Performances

Abstract

The study was evaluated speed control undulations (SCUs), as one of the crucial speed management tools in urban areas, performance in reducing passenger car speeds. The evaluations investigated two narrow-type SCU (Bump) and two wide-type SCU (Hump) with 5 cm and 10 cm height. The performance of SCUs in reducing vehicle speeds has been examined by reading speed values from video records. Vehicle speeds have been determined at a distance from the SCUs that does not affect the speed of the drivers (approx. 125-150 m) and also at a distance of -60 m, -40 m, -20 m, 0 m (passing over), +20 m, +40 m and +60 m according to the SCU. All speed measurements were made in two different traffic flow regimes, free flow (FF) and oversaturated flow (OSF). Between the measured vehicle speeds and speed reduction rates, statistical evaluations were made for each SCU at different measurement points and the exact measurement points between different SCUs. It has been determined that the 10 cm high hump would be the right choice for reducing vehicle speeds.