Effect of Road Surface and Bed Clearance on Truck Tire Noise

The sound level of crossbar-type truck tires was found to be only slightly affected by the texture of the portland concrete road surfaces used. Rib-type tires showed higher noise level on coarse than on smooth surfaces, but the ranking of different tires was unaffected. Clearance of the truck bed above the tire was relatively unimportant. Noise level increased with increase in speed. Sound persistence after truck passby is related to tread design and possibly to the radiation pattern from the road-tire interface.