Centerline Rumble Strips: Study of External Noise

Centerline rumble strips (CLRS) are patterns installed on the center of undivided, two-lane highways. Their main function is to alert drivers by producing noise and vibration. This treatment has been demonstrated to be effective in reducing crossover crashes. However, there are some disadvantages in their utilization, such as the exterior noise created by the strips. The objectives of this study were to quantify the levels of exterior noise; to verify the effects of speed, vehicle, CLRS shape, and distance on exterior noise; and to investigate the amount of noise created by CLRS that affects roadside residences and businesses. Two types of vehicles [2006 Ford Taurus (sedan) and 2008 Chevrolet Express (15 passenger van)] were driven over two different patterns of milled-in CLRS and over smooth asphalt pavement at two different speeds. Researchers collected the noise levels at three distances from the road at 10 different locations. Results indicated that vehicle type, speed, CLRS presence, and distance affect exterior noise levels. CLRS noise levels were statistically greater than smooth pavement noise levels, and the difference would be perceived by human ears at distances up to 45 meters.