Acoustic Beamforming: Mapping Sources of Truck Noise. NCHRP Report 635

摘要

Heavy trucks are significant contributors to overall traffic noise levels. At highway speeds, the noise level produced by heavy trucks is about 10 dB greater than that of light vehicles. As a result, every heavy truck in the traffic flow contributes the same amount to the average noise level values as 10 light vehicles. Because of this significant contribution, a thorough understanding of the trucks as a noise source is crucial to the prediction and mitigation of traffic noise. Noise from heavy trucks originates from a variety of sources, which include exhaust stack outlet, muffler shell, exhaust pipes, engine block, air intake, cooling fan, tires, and aerodynamics. The relative contributions of these sources vary with vehicle type, operating condition, and (for tire noise) the type of pavement.