Super heavy trucks started to operate on the finnish road network – how do the roads survive?

A new legislation increasing the allowable maximum total truck weights from 600 to 760 kN was launched in Finland on October 1st, 2013. According to the new legislation maximum truck weights even exceeding 1 MN (100 tons) have since then been allowed on certain important transportation routes with special permission. Introduction of the new truck masses has enabled positive development in the transportation efficiency and reduction in the amount of traffic induced emissions. At the same time, however, questions have arisen regarding the loading effect of super heavy trucks on the road infrastructure. Especially so because it is well-known that in international comparison the thickness of asphalt concrete layers on Finnish roads is typically fairly small.
This paper makes an overview on the research that has been carried out regarding the loading effect of super heavy trucks in Finland from summer 2013 to summer 2016. These include comparisons of the loading effects of different types of tire configurations, mechanical behavior of steel and plastic culverts located at shallow installation depths, loading tests made for investigating the pumping of water into the road structure on water saturated soft subgrade soils and monitoring of the rutting rates a selection of roads being exposed to the increased truck loads.