Condition Assessment of Road Markings in Denmark, Norway and Sweden—A Comparison Between Retroreflectivity, Visibility and Preview Time

Longitudinal road markings provide visual guidance for drivers and are essential for safe driving, particularly at night. The aim of this study is to investigate possible differences in road marking performance, with regard to retroreflectivity, visibility and preview time between Denmark, Norway and Sweden. The results are compared to current recommendations and regulations regarding road marking performance in the three countries. This study is based on condition assessments of 30,000 km of edge road markings from 2017 to 2021. The results showed that the performance requirement fulfillment for retroreflectivity of white road markings (150 mcd/m2/lx) is 38% in Denmark, 65% in Norway and 66% in Sweden. No large differences in dry road marking performance were found between the three countries. The performance regarding all variables was rather stable during the five years investigated. The mean preview time was 4.7 s in Sweden, 4.9 s in Norway and 5.6 s in Denmark. The observed preview times are higher than the recommended minimum preview times (ranging from 1.8 to 3.65 s) found in the literature. The results do not raise any need for revision of the current regulations regarding road marking retroreflectivity and geometry in Denmark, Norway and Sweden.