Abstract
Instruments used by Finnish road authorities are: Finnish Road Monitor which is based on ultrasound measurement; profilograph; 3D map vision which is based on laser and video. Riding comfort is determined by longitudinal road profile. This is characterised by IRI (International Roughness Index) value which is combined with transverse profile measurements. IRI is measured by Road Monitor and Roadman. The latter is found reliable. Measurements are also made of friction (for lateral force and braked wheel), optical properties, dynamic load on vehicles (with a strain gauge on rear axle or by simulation), bearing strength (with plate loading and falling weight measurement, high speed deflectometer).