Response-type road roughness measuring systems estimate pavement roughness from correlation equations.
Most of these systems recommend to maintain a constant survey speed or to keep the speed within a certain range. But
carrying out a survey with this speed constraint may not always be possible due to the existence of traffic control devices
and heavy traffic flow. Therefore, these systems may produce a significant bias in roughness measurement because of
survey speed fluctuations. The objective of this study is to develop calibration equations that eliminate the bias produced
by survey speed fluctuations. A simplified regression relationship for IRI with bump integrator reading and survey speed
as explanatory variables is developed using ROMDAS bump integrator. Using a case study, this study also investigates
how the bias created by speed fluctuations affects roughness and demonstrates how developed calibration equations
eliminate that bias.