Resumen
In many European countries including Hungary, winter conditions produce disruption of traffic, as well as the increase in road users? (vehicle operating, time delay and accident) costs. In most areas, the severity of winter conditions varies from year to year. Modern society has become more vulnerable to these effects. The primary objective of winter maintenance is to provide snow and ice-free conditions on the highway network. Compared with other road activities, winter maintenance is characterized by the need for a fast response, and by the impacts of the measures taken being short-lived. That is why scientifically based methodology (optimisation of winter maintenance techniques) is needed to reduce the above negative consequences. The main aim of the research work carried out at KTI Non-Profit Ltd, Budapest was to optimise the efficiency and the timing of salt storage and road de-icing policy as a function of environmental, economic and traffic safety aspects. The selected methodology, Capacitated Arc Routing Problem helps the road managing agencies in optimising road winter maintenance fleet routing, with reduced air pollution, fuel consumption, in accelerating the related activities, besides in reducing road user costs significantly. In the research work performed several scenarios on different decentralisation levels of salt storage depots were also modelled, and investigated from environmental and economic view-points. The scenario on heavy de-icing vehicles of standard load capacities with a centralized depot was considered as standard variant, while the heavy vehicles of variable load capacities and the silos with unlimited capacities were also modelled. A Cost Benefit Analysis of the timing of salt depot decentralisation proved that the immediate set-up of silos is the most economic and efficient variant. The methodology developed can also help the local road administrations in devising their winter policy documents covering the related objectives, standards, intervention levels, priorities for action within the road network, the response times, snow clearing and salting routes, salt spreading rates, and personnel strategy.