Texture (roads)

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Road surface textures are deviations from a planar surface, affecting the vehicle/tyre interaction. Pavement texture is divided into: Microtexture with wavelengths from 0 mm up to 0.5 mm; Macrotexture with wavelengths from 0.5 mm up to 50 mm; Megatexture with wavelengths from 50 mm up to 500 mm.

Microtexture[edit]

Microtexture (MiTx) provides dry friction and is a desired road property.

Macrotexture[edit]

Macrotexture (MaTx) is partly a desired property and partly an undesired property. Short MaTx waves, about 5 mm, acts as acoustical pores and reduce tyre/road noise. On the other hand, long wave MaTx increase noise. MaTx provide wet road friction, especially at high speeds. Excessive MaTx increase rolling resistance and thus fuel consumption and CO2 emission contributing to global warming. Proper roads have MaTx of about 1 mm Mean Profile Depth.

Megatexture[edit]

Megatexture (MeTx) is pure road damage, causing noise and vibration. MeTx below 0.2 mm Root-Mean-Square is considered normal on proper roads.

Measurement[edit]

MaTx and MeTx are measured with laser/inertial Profilographs. Since MiTx has so short waves, it is preferably measured by dry friction brake tests rather than by profiling. Profilographs that record texture in both left and right wheel paths can be used to identify road sections with hazardous Split friction.

References[edit]