Road surface textures are deviations from a planar and smooth surface, affecting the vehicle/tyre interaction. Pavement texture is divided into: microtexture with wavelengths from 0 mm to 0.5 millimetres (0.020 in), macrotexture with wavelengths from 0.5 millimetres (0.020 in) to 50 millimetres (2.0 in) and megatexture with wavelengths from 50 millimetres (2.0 in) to 500 millimetres (20 in).
A van pulling a road profilometer (undated, before 1969).
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other.
Types of friction include dry, fluid, lubricated, skin, and internal.
Simulated blocks with fractal rough surfaces, exhibiting static frictional interactions