Lietuvos žvyrkelių tobulinimo perspektyva

Abstract

Nearly 50 percent of Lithuanian state roads are gravelled. The conditions of majority of gravel roads are unsatisfactory not only regarding standards for road maintenance parameters such as pavement roughness, rutting, and cross sectional slopes, but also regarding requirements for road shoulders and water proofing system. Gravel roads often not satisfy traffic safety requirements: sight distances of nearly 40 percent of gravel roads sections are less than 200 m. In certain regions the gravel road width is from 20 to 70 percent less, than it is required according to the norms. The gravel pavement is worn out: the average depth of gravel pavement is less than 20 cm, the depth of the frost resistant layer is not adequate. The average depth of the frost resistant gravel pavement layer is less than 50 cm, what is required accordind to the road design norms as a minimal standard. The percentage of aggregate with the diameter of more than 5 mm is also 30 percent less than for gravel pavement required. Pavement bearing capacity is less than standard requirements. The program of upgrading Lithuanian gravel roads must be based on the existing conditions of gravel roads, traffic safety requirements and financial possibilities of the Road Fund.