**4. Conclusions**

The importance of optimizing winter road maintenance operations for achieving goals of environmental sustainability in the transportation sector is presented in a practical case study. Environmental impacts can be significantly reduced if the agency responsible for winter road maintenance optimizes the timing of operations and in this way uses less salt for road gritting. Moreover, the precise timing of winter road maintenance operations is of crucial importance for enabling smooth and undisturbed mobility of road traffic passing the road during a snowstorm event. Fuel consumption of road traffic and related exhaust emissions increase in case of disturbances and congestion due to snow accumulation on the road.

Currently, vehicles operating on fossil fuels still dominate road traffic in most countries. Ensuring smooth, undisturbed mobility of road traffic during snowstorm events is of great importance from an environmental point of view. For this reason, optimized in-time operation of winter road maintenance in case of snowstorm events can significantly contribute to a reduction of environmental pollution and achieving goals proposed in the European Green Deal for reducing net greenhouse gas emissions. However, it can be assumed that electric vehicles will dominate road traffic in the next decades. But heavy-duty trucks run on diesel fuel will likely be used for a longer period of time. Electric vehicles do not cause exhaust emissions on the road, however, there are indirect emissions taking place at power plants etc. These emissions depend on the share of electricity derived from renewable or non-renewable resources used for charging electric vehicles. Anyway, driving conditions (road with snow cover, snow-free road) may not have a significant impact on indirect emissions caused by road traffic with electric vehicles. But, the importance of providing safe driving conditions, due to optimized in-time operation of winter road maintenance will remain. Optimized road salt consumption will still be of great importance to reduce environmental impacts such as global warming potential, abiotic depletion of mineral resources, human toxicity, and eco-toxicity-related impacts.
