Abstract: Road agencies need to estimate road roughness when determining the economic evaluation of proposed maintenance and upgrading options, and in pavement management systems for planning and programming purposes. Instrumented measurement of roughness is desirable, but when instrumented measurement is not feasible, for example in the case of unpaved roads, recourse must be made to subjective estimation. This note presents two approaches to subjective estimation, both based on the World Bank's work in the development of the Highway Design and Maintenance Standards Model, HDM-III, and the Highway Development and Management Model, HDM-4.