The indicator shows the proportion of county roads that are classified as having a poor or very poor surface. County roads with poor or very poor surface: Based on measured values of traces according to the International Roughness Index (IRI) taken from car-mounted measuring equipment. Data source: The National Road Database of the Norwegian Public Roads Adminstration. County roads: The total county road network in the county. Data source: The National Road Database of the Norwegian Public Roads Adminstration.