Statistical Analysis of Gravel Road Rating

This paper presents a statistical analysis of the method for gravel road rating used in Sweden. The findings are used to develop a new method. The study is based on the condition of about 20,000 sections of gravel road, each with a length of 100 m. The influence of climate zones, road authority regions, administrative provinces, traffic volumes, road widths, speed limits, and dust control material on the condition of the sections is studied. The analysis uses cross-tables combined with Goodness-of-fit test, as well as simple linear regression and logistic regression. The findings indicate that the method is not completely valid for accurately describing the condition of gravel roads. The results also show that the method is unsuitable for monitoring road condition. Therefore, certain adjustments are presented for making this method more accurate in describing the condition of gravel roads.