Polering av högkvalitativa beläggningar : en förstudie

Polishing of high quality pavements : a pilot study

Sufficient friction between tire and pavement is a prerequisite to ensure high traffic safety. Polishing of stones in the surface course risks causing low friction and is a problem that has gained bigger attention outside the Nordic countries. In Sweden it has been noticed that the studded tire traffic during the winter roughens the pavement surface enough to endure some polishing during the summer months. The bare ground friction has thus been allowed to vary over the year since interaction between polishing and roughening has been working well with sufficient friction even at its minimum. This interaction now seems to be out of play as repeated friction measurements on highly trafficked roads indicate an even faster polishing and in the worst case absent roughening. The background of this project is the results from repeated measurements that show critically low friction on highly trafficked road sections. The friction measurements were initiated after a car crash that got lots of attention since it was caused by lost grip and the following measurement demonstrated critically low bare ground friction.  In this project, some possible factors are examined to why the roughening effect that earlier has been obtained during wintertime has decreased. It is presented that the traffic volume on the most heavily trafficked roads has increased, the use of studded tires has decreased substantially during the last decade and the studded tires are designed to cause less wear on pavement. The increased use of friction tires has also contributed to increased polishing during the winter months.  The friction measurements have within the project been performed on a test section on E4 and on several highways around Stockholm. The results from the test section confirm that a harder porphyry with lower ball mill value in the surface course is more susceptible to polishing compared to softer stones. The tradeoff between abrasion resistance and polishing also becomes clear since the harder porphyry shows less abrasion wear (rutting) compared to other pavement sections.  Measurements performed on highways around Stockholm show that the problem with low friction isn’t isolated to some single pavement section. On nine out of twelve roads, friction values below 0.5 are measured, the limit value determined by the Swedish Transport Administration under the guarantee period, on at least one 20 m section. On two out of the twelve examined highways it is demonstrated that the friction is lower than the limit value along the whole studied section.


  • Swedish

Media Info

  • Pagination: 110p
  • Serial:
    • VTI Rapport
    • Issue Number: 1146
    • Publisher: Swedish National Road and Transport Research Institute (VTI)
    • ISSN: 0347-6030

Subject/Index Terms

Filing Info

  • Accession Number: 01878547
  • Record Type: Publication
  • Source Agency: Swedish National Road and Transport Research Institute (VTI)
  • Files: ITRD, VTI
  • Created Date: Apr 3 2023 4:47PM