Road noise, texture, and skid resistance

A major dilemma facing highway engineers and designers is in providing a balance between traffic noise and highway safety. Amount of skid‐resistant texture applied to the pavement is a major influence on surface noise level. With concrete pavement, texture consists of shallow transverse grooves. Transverse‐textured concrete may be noisier than random‐textured bituminous surfacing for any given texture depth. However, the concrete surface is more effective in maintaining high‐speed skid resistance. Studies conducted in England show that a single linear relationship exists between tire noise level and effectiveness of texture in terms of change in BFC (braking force coefficient), a measure of skidding resistance. For the same level of skid resistance, a bituminous surfacing with 2.0‐mm texture depth emits the same level of noise as concrete surfacing with 0.8‐mm texture depth. It is thus possible to specify separate texture depths for concrete and bituminous surfaces with the knowledge that not only are they equivalent in terms of road safety, but also that each will emit roughly equal tire noise levels.