COMPREHENSIVE STUDY ON ROAD ROUGHNESSRoad roughness is the deviation of the road surface from a true flat surface with characteristic dimensions which affect vehicle dynamics, ride quality, dynamic loading and drainage, e.g. longitudinal profile, transverse profile and transverse slope (ASTM E867). By causing vibrations in the vehicle, roughness has a direct influence on wear, driving comfort and vehicle safety. The relationship between vehicle operating cost and road roughness is well established through several studies conducted in India and abroad. Roughness measurements are an important factor in making decisions about allocating limited budgets for maintenance and improvements. For this reason, roughness specifications have been adopted by various highway engineering agencies (Sayers et al, 1986). The longitudinal and horizontal roughness variation parameters are wave irregularities, wavelength, amplitude, frequency, speed (vehicle characteristics, tires, seat suspension, body support, weight, etc. ) and perception (passenger sensitivities to acceleration, speed, resonance and resonance). ...