Reduction of negative impact of salts used for winter road maintenance on the environment

Abstract

Winter in Lithuania is the most complicated time of the year to ensure the functioning of transport systems. The main factor which impedes a normal operation of the systems is weather conditions making a direct influence on vehicles and infrastructure elements of transport systems. Precipitation, low air temperature, strong wind and other unfavourable weather conditions impede traffic on the roads and streets. In Lithuania, like in other countries of the world, for the purpose of winter road maintenance (to reduce pavement slipperiness) chemical materials on a basis of chlorides are used (NaCl, CaCl2, NaCl + CaCl2 mixes), the annual amount of which spread on the roads and streets of Lithuania comes to 160 thousand tonnes. Though salts, used for road maintenance, are able to immediately ensure safe traffic conditions, they all have larger or smaller negative impact on the environment which depends on the composition of salts, the amount used and interaction with other environmental components. A negative environmental impact comprises: ground (soil) contamination; water pollution (surface, ground and underground); impact on flora, fauna and human beings; corrosion (of vehicles, roads and reinforced concrete structures); deterioration and deformation of road pavements. Based on the increasing requirements in the field of traffic safety, environmental protection and ecology it is necessary to search for the most effective and less damaging measures to ensure road maintenance in winter: to improve planning and management of winter road maintenance; to implement modern snow cleaning and ice removal technologies; to put into practice preventive road maintenance measures; to use alternative materials and inhibitors which reduce a negative environmental impact.