Published: Less than 30 min ago
The problem of polished and smooth roads is spreading. The consequence is an increasing risk of serious traffic accidents, warns the Norwegian Road and Transport Research Institute.
The state research institute VTI has carried out a preliminary study in which they investigated the cause of how it is that country roads and traffic routes are affected by the phenomenon that they become polished – that is, completely smooth.
This since a number of difficult-to-explain accidents occurred during the fall of 2018 on the E4/E20 where the road surface was perceived as slippery.
“The situation is serious considering the friction requirements set by the Swedish Transport Administration and the fact that the majority of roads that we have examined turn out to have worse friction. In our preliminary study, we have started by highlighting some possible causes,” says Henrik Bjurström, project manager and researcher at VTI, in a press release.
In addition to increased traffic in the form of, among other things, larger and heavier vehicles, the use of friction tires, i.e. winter tires without studs, is also believed to have an effect. These polish the road surface more than even summer tires, VTI writes.
When traditional studded tires are not used, the roughening of the road during winter is also reduced and in some cases stops completely.
However, the problem has spread from having previously mostly affected places such as roundabouts, sharp curves or traffic lights, writes VTI.
According to the authority, a solution to the problem could be a different type of road surface where you stop using hard-wearing stone materials such as porphyry to thereby create friction.
“On them, the new type of studs don’t bite so that it roughens up the surface. Instead, the stones are polished to become smooth and slippery,” says Henrik Bjurström.