Over the years the decisions for winter road maintenance tasks were made by on duty employees in the units, and the quality of such decisions were highly dependent on their experience and competence. In 2018 AB „Keliu prieziura“ started using a state-of-the-art road condition forecasting system (Road status information system – RSIS), that produces a new forecast every 1 hour and displays current and future road condition maps (Forecast).

What is RSIS?
Road network is split into segments with a particular climate characteristic for each, that depends on road structure, natural and anthropogenic environments, and other factors affecting road condition. Every 1 hour the system collects data from various sources, e.g. road weather stations, numerical weather prediction model, winter road maintenance task information from Purchaser, etc. This data is then processed and a 18h forecast is calculated according to the climate characteristic for each road segment. The Forecast is available through graphical user interface and application programming interface (API). When RSIS indicates slippery road sections, e.g. ice on road, it provides a task recommendation. The decision making of whether, where and how many spreaders and/or other equipment is needed is being left for an employee, who makes a call out for a salt spreading, road clearing or another task. During the adverse winter weather at times there is a need to deploy all 300 spreaders and other equipment at once, thus, route planning and resource management becomes an arduous process. Moreover, constantly updating information on road conditions is a crucial factor in decision making, determining the way a task must be performed. In order for AB „Keliu prieziura“ to perform the tasks and activities effectively, a need arose for automatic planning and routing of the spreaders and other equipment, that would consider the Forecast and available resources (Dynamic route planning).

Current solution limitations

• Every year before the winter season a set of optimal routes are being made according to the service areas and resources, and will only be adjusted if a significant change in management, road classification, or other area is done (Static route planning);
• Route correction in operational work according to the weather is performed by on-duty employees, thus, there is a high risk of human factor;
• Formation of ice on road is more often patchy than not, therefore, it usually is ineffective to spread slipperiness reducing materials on a whole road;
• The amount of salt that is needed is usually decided upon by the on-duty employee, who often does not follow RSIS recommendations;
• The decision of whether to call-out the spreaders is left for on-duty employees too, instead of a centralised road maintenance centre;
• The drivers receive the callouts using text or verbal communication, instead of maps or navigation apps.