2001 - Sweden - Estimations of Roughness on Roads with Low IRI-Values

Study that focussed on the subjective experience of roughness on roads with low IRI-values. Using the available roughness data it was also studied how much a random error, added to the IRI-values, would influence the calculated correlations with the subjective estimates. The investigation was carried out as a magnitude extimation experiment, in which some 20 observers made their estimates while travelling as passengers first in a car, and later in a lorry.