The Intelligent Winter Road Maintenance

Available online at www.sciencedirect.com

ScienceDirect Procedia Engineering 111 (2015) 410 – 419

XXIV R-S-P seminar, Theoretical Foundation of Civil Engineering (24RSP) (TFoCE 2015)

The intelligent winter road maintenance management in Slovak conditions Andrea Kociánová* Department of Highway Engineering, Faculty of Civil Engineering, University of Žilina, Univerzitná 8215/1, Žilina, 010 26, Slovakia

Abstract The paper describes a multi-level solution for intelligent winter road maintenance management. The system is based on monitoring and forecasting of weather conditions and the road surface conditions at selected road locations. Automatic data collection and transmission is ensured by road weather stations, which provide early warnings about dangerous situations on the road (such as frost, ice, mist, wet or snow-covered surface). Data from these weather stations, together with weather forecasting models and date from weather radars and satellites are processed, presented and used for prediction of the pavement surface state and temperature. The result is information support for right maintenance decision and for effective and timely treatment of roads in the winter. Further part of the system is the winter maintenance dynamic dispatching which provides on-line fleet monitoring and management to ensure optimization and timely intervention. In addition, variable message signs are in the system for ensuring of information for drivers or even for traffic control on a dangerous road sections with the aim to improve traffic safety. © 2015 The Authors. Published by Elsevier B.V. © 2015 The Authors. by Elsevier Ltd. This is ancommittee open access of article theR-S-P CC BY-NC-ND the under XXIV seminar,license Theoretical Foundation of Civil Peer-review underPublished responsibility of organizing (http://creativecommons.org/licenses/by-nc-nd/4.0/). Engineering (24RSP) responsibility of organizing committee of the XXIV R-S-P seminar, Theoretical Foundation of Civil Engineering (24RSP) Peer-review under Keywords: Winter road maintenance; Road weather; Fleet management; Decision support.

1. Introduction An important part of the maintenance activities of the road administrators is a winter road maintenance which is necessary to enable road transport during winter. Delay of possible intervention could directly threat the safety or the

* Corresponding author. Tel.: 421-41-513-5912 E-mail address: [email protected]

1877-7058 © 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license

(http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of organizing committee of the XXIV R-S-P seminar, Theoretical Foundation of Civil Engineering (24RSP)

doi:10.1016/j.proeng.2015.07.109

Andrea Kociánová / Procedia Engineering 111 (2015) 410 – 419

flow of traffic. On the other hand, any unnecessary interventions are significant costs. For this reason, these interventions should be optimized at a time and place when it is convenient. Effective management of winter road maintenance is only possible on the basis of relevant information about current and future road weather and surface conditions on specific road sections. Such information together with information about movements and performed maintenance of each vehicle in real-time create the basis for support of winter maintenance decision process and for efficient fleet management. The result of intelligent winter road maintenance is thus effective winter maintenance with cost saving as well as increased safety on the roads, increased flow of traffic and decreased environmental negative impacts in winter time The basic components and scheme of the intelligent winter road maintenance management as well as current situation and proposed concept of implementation of this system in Slovak conditions, are described in the article. 2. The Intelligent Winter Road Maintenance Management The aim of intelligent winter road maintenance management is to give the dispatcher and driver spreaders a set of intelligent tools that will help them optimize their work. 2.1. Dispatcher, driver and maintenance vehicles Dispatcher and driver The main task of a dispatcher is to manage maintenance – continuously monitoring development of weather and road weather conditions, deciding on deploying maintenance crews in certain parts of given region and determining appropriate technology and intensity of maintenance (e.g. technology used, amount of spreading). The dispatcher is also responsible for keeping records during maintenance – keeping the so-called winter maintenance diary and record performed procedures. Here it is important to have an appropriate software tools for the dispatcher that will facilitate these activities in order to devote maximum time to maintenance management. The driver is equally important, because he is responsible for quality of the actual performance of maintenance in the field. Maintenance vehicles In the context of intelligent winter maintenance management it is necessary to prepare intelligent maintenance vehicles, especially spreaders, and optimize maintenance circuit configuration. Technological equipment of spreaders includes mainly technical facilities for performing the winter maintenance. The vehicles have to have an on-board electronic unit to control the operation of ploughing and spreading from the cab (continuous adjustment of weights and spreading width, setting of lateral spreading). Spreaders should also be equipped with a position tracking system - Automatic Vehicle Location System (AVLS). The system is able to send online data about the vehicle movement (information about position and time of maintenance) as well as parameters of performed maintenance (e.g. information on ploughing yes/no, spreading material and its amount, width of spreading, etc.) into the database on the server. Data are located using the GPS module and transmitted online via wireless network (e.g. GPRS) into the database of dispatching for fleet management as well as for subsequent processing and utilization, for example for the purposes of reports of performed maintenance within the road weather information system or for accurate of road weather forecasts within the maintenance decision support system. Newly the spreaders can be equipped with additional sensors for measuring surface temperature, ambient temperature or road condition during driving. Together with information from an AVLS the data should be transmitted to the data centre. Data from these contactless sensors give immediate information to the driver while driving, as well as the dispatcher, who is monitoring the spreaders for evaluation and registration of intervention. These mobile road weather data can also be used as an input into road weather information system and maintenance decision support system as well as a supplement for the thermal mapping (TM). TM is a technique for data collection and analysis, which seeks to describe in detail the variability of road surface temperature in the road network at certain specific weather conditions.

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Intelligent spreader can have pre-programmed spreading parameters for certain parts of its maintenance circuit (typically it is static spreading width adjustment). They are set on the basis of the GPS known position of the vehicle on the road network. But it is only static spreading control without consideration of the current and forecast road conditions. Higher level of intelligent winter maintenance can be ensured by engaging the so-called dynamic spreading control. The type and amount of spreading material is determined based on the current and predicted conditions on the road in a specific part of the maintenance circuit using a dynamic calculation model. Spreader has thus already pre-set specific scenarios of spreading before the ride (where and what intensity), to which, of course, the driver can manually intervene. This is not only a support for the dispatcher, but also a direct assistance for driver. One the part of winter maintenance there are also personal vehicles for validating rides. During these rides additional metrological sensors (mobile road weather stations) can again be used – which will objectively detect and especially record actual conditions on the roads. The dispatcher thus has objective data (surface temperature, air temperature, surface condition and friction) to assess the need of maintenance. 2.2. Information about road weather and surface conditions To achieve high quality and efficiency of winter maintenance it is necessary to have relevant data about the weather and road surface conditions. They can be obtained from various sources. The most important source of real time meteorological and pavement data are road weather stations (RVS) ensuring automatic data collection and transmission. They are an essential tool for remote monitoring of weather conditions on the roads. Generally there are two basic types of locations for the RWS: representative and critical. Stations in the representative location can provide perspective of the situation, which can be applied/generalize to a relatively larger part of the area (road network). Stations in the critical location are used mainly for early detection of adverse weather conditions in the region (generally they are setup at the coldest points of the roads and bridges). The RWS are equipped with variable set of sensors for measuring of meteorological date (air temperature, relative humidity, wind speed and direction, precipitation, visibility, remote sensors and others). They are also equipped with road sensors connected to the station for measuring of road conditions (e.g. road surface temperature, road surface status - dry, wet, moist, snow, ice; water layer thickness, freezing point, salt concentration, friction and others). Traditionally, road sensors are embedded in the pavement (typically two pavement sensors in a location). Newly, there are promoted contactless sensors, which are just “looking” on the road surface as a camera, located on the side of the road. A novelty of last year is a Swedish provenance weather camera that scans the road surface and classifies its status in the two-dimensional perspective. It is a revolutionary advancement. Some road weather stations are equipped with overview camera for visual monitoring of road status and actual weather (add-on night vision). The RWS also provide early warnings about dangerous situation on the road (such as frost, ice, mist, wet or snow-covered surface) and allow direct control of connected variable message signs (VMS) warning drivers of impending danger. In some cases, installed defrosting sprays may be activated, when it is necessary. Static RWS are standing isolated only in selected locations on the road network and there are no data between them. A maintenance vehicles and inspection personal vehicles with additional meteorological sensors thus actually become the mobile road weather stations. Other sources for monitoring weather and road conditions are meteorological radars and satellites, National Weather Service (NWS) with their own climatological stations, other systems that collect road weather data, other systems that include cameras as well as a mobile weather data from intelligent cars which may be involved in the process in the future. 2.3. Software support for dispatchers Dispatcher needs software support for proper and effective management of winter maintenance.


Road weather information system (RWIS) is a software tool which collects all relevant available data which can be used by dispatchers to support decision making in winter road maintenance management. More convenient are web systems which allow internet access from anywhere, possibly even from a mobile device. The RWIS provide a comprehensive overview of historical data, current real-time data and predicted data about road weather and surface conditions. All these data as well as trigger warnings are displayed in a format that can be easily interpreted by a dispatcher; they are visualized by using graphs, tables and maps. The RWIS may also, in addition to data and information, directly provide the dispatcher recommendations on winter maintenance. The RWIS also collects data from AVLS and thus can serve as a tool for registering and checking of maintenance performance. The benefit is an integration of all the necessary tools into one unit and integrated system. The RWIS integrates current data from road weather stations, meteorological radars and satellites, cameras, mobile road weather stations, the National Weather Service (NWS) and others. The RWS ensure recording of current conditions in selected locations, but the RWIS can include forecasting module, which will allow for each RWS to generate a point forecast of important parameters in response to the measured data and general weather forecast. General weather forecasts are generally supplied by the NWS, alternatively by a commercial provider. In addition, there are specialized computational models for specialized forecast for road surface. The specialized road weather forecast model is a part of dispatcher maintenance decision support system. Maintenance decision support system (MDSS) is a part of RWIS focused on special linear weather and road surface status forecast and recommendations on winter maintenance. These are computer systems which generate predictive outputs on the basis specific inputs. It is a useful assistant for dispatcher, which can specify the weather situation development. Road weather forecast (road condition, road surface temperature, freezing point temperature and snow amount) plays an important role in the timely intervention of winter maintenance Road weather forecast (RWF) should be differentiated on the medium-term RWF (over the next two days) and short-term RWF (within the next 12 hours). Medium-term forecast is for the activation of capacities – preparation of maintenance vehicles, drivers or spreading materials. Short-term forecast is a basis for immediate decision-making in winter maintenance management. The short-term forecast should be targeted on individual road sections no longer than the unit kilometres. Accurate targeting short-term forecasts allow in consequence so-called selective approach to maintenance. It can significantly save resources that, in specific cases will be treated only the part of sections that really needs maintenance action. Savings are generated by right scheduling of maintenance vehicles departures (timeliness, frequency), and by the selective treatment of maintenance circuit. Special linear prediction is based on a physical model of the weather development and its effect on the road surface. This gives the dispatcher the most accurate overview of the temperature and surface condition development of each road section. Model responds to measured data from road weather stations and expected weather development obtained from available general meteorological model (e.g. ALADIN numeric weather prediction model). Predictions are created on the basis of historical, current and predicted geographically localized information about weather and road surface conditions as well as further static date (e.g. pavement construction/bridges, topography data, land use data, watercourses near the roads, thermal mapping etc.) and dynamic data (e.g. traffic flow data, maintenance data, mobile road weather data etc.). Mobile road weather data from maintenance vehicles (data from meteorological sensors) can also be used for RWF computational model. By adding mobile data among input data for RWF computational model it can be thickened a network of known points from static stations and then refined forecast. Another important source for RWF model should be GPS data from the spreaders about performed maintenance in the recent past. The model itself predicts the meteorological weather developments and can predict the emergence of ice on selected road section. GPS data, however, provide valuable feedback - for example, that this road section was an hour ago sprinkled by salt in the weight of 25 g/m2. This information should be taken into account in prediction model and for the nearest hours (depending on weather condition) ice warnings should be suppressed from the forecast. In addition to the linear prediction the MDSS system can based on constantly ingesting data from road weather and atmospheric data, reviewing current treatment operations, and analysing the latest road weather forecasts

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produce treatment recommendations for winter maintenance operators. It is very useful tool for non-experienced operators, which can take get recommendations on what treatment strategies needed to be taken and they can take the right decision where and when road maintenance should be performed. Both of the above mentioned modules of course have to be updated best once an hour to always provide timely forecasts based on the most recent input data. The basic components and scheme of intelligent winter road maintenance management is shown in Figure 1.

Fig. 1. The basic components and scheme of intelligent winter road maintenance management

Assessment of winter maintenance performance and costs based on so-called Winter Maintenance Index (WMI) are additional services which can system of intelligent winter road maintenance management provide. On the basis of WMI it is possible to evaluate adequacy of winter maintenance performance in relation to real meteorological conditions over a defined road network. The maintenance is either insufficient or over-priced. The purpose of WMI is to give an objective indication of winter severity, and especially to compare maintenance performances among different contractors or centers working in different climate conditions. This evaluation system has the potential to unify the quality of maintenance and optimize the scope of the conducted performance [2]. 3. The current situation in the Slovak Republic 3.1. Responsible organizations for winter maintenance Responsible for the winter road maintenance in the Slovak Republic are owners or administrators of the roads. Roads of Ist and higher class are owned by the state, which is represented by the Ministry of Transport. Highways and motorways are administrated by the National Highway Company (NHC), which also performs winter maintenance by its own departments. The NHC operates 14 local maintenance centres, Centres of Administration and Maintenance of Highways and Motorways, and one centre for specialized activities. Only a small part of winter maintenance of highways is performed by contractors. Roads of Ist class are administrated by the Slovak Road Administration (SRA), but maintenance is performed by contractors – mainly regional-funded organizations. Roads of IInd and IIIrd class are owned by Self-Governing Regions (SGR). Present division of the road network reflects the administrative boundaries of 8 self-governing Slovak regions. Regions perform the administration and maintenance of roads mainly by their own region-funded organizations, the Administration and Maintenance of Roads (AMR). In total there are 8 AMR centres included 38 regional maintenance centres (more than 100 local maintenance centres). There is no winter maintenance head office in Slovakia which would give instructions to the road masters. Table 1 shows the extent of road network and road administrators in the Slovak Republic.

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Andrea Kociánová / Procedia Engineering 111 (2015) 410 – 419 Table 1. Status of the road network in the Slovak Republic by January 1, 2015 [1]. Length of the road [km] National Highway Company Highways + Highway Feeders 420 + 1

Motorways + Motorway Feeders 252 + 13

Slovak Road Administration Ist class roads 3 293

Self-Governing Regions IInd class roads 3 616

IIIrd class roads 10 369

Total 17 964

3.2. 3.2. The legislative framework of winter maintenance The legislative framework for winter road maintenance is stipulated in Act No. 135/1961 Coll., on roads, and the Ministry of Transport Decree No. 35/1984 Coll., implementing Act on roads stated above. In the Slovak Republic there is no standardization of winter road maintenance. There are two technical guidelines TP 08/2013 (for roads) and TP 09/2013 (for highways), which lay basic principles and standards for the performance of winter maintenance and winter maintenance technology. In accordance with these guidelines, an internal rules document for each regional centre must be prepared before each winter season - the operational plan of winter road maintenance. This plan is a fundamental document describing winter maintenance organization in detail. It contains all information about the dispatching centre, maintenance vehicles, key persons, spreading materials, configuration of maintenance circuits for each vehicle, the system of maintenance, etc. The winter maintenance procedures (type and time of action, salting route duration) are established on the basis of the road category (infrastructure characteristics, economical importance) and both the weather circumstances and the traffic conditions. 3.3. Maintenance vehicles The NHC and many of regional dispatching centres of the SGR monitor and manage their vehicles, which are equipped with a position tracking system (GPS/GPRS). The system gives information about the vehicle movements (position and time) and performed maintenance (ploughing yes/no, spreading yes/no, weight and width of spreading). Meteorological sensors are not used. Position and performed maintenance of vehicles is displayed on the map in each maintenance centre that monitors and controls their own vehicles. The GPS floating car data and GPS maintenance data are not transmitted to the central database. They are accessible only for suppliers (contractors which provide winter maintenance), not for road administrator. For example, the SRA have no access to the GPS data from any regional centre (AMR centre of SGR), which carries out winter maintenance on the Ist class roads. 3.4. Information about road weather and surface conditions Source of information about road weather and surface conditions are road weather stations, but only in selected Slovak road network. Available for dispatchers to make decisions on performed winter road maintenance there are often only weather information and weather forecasts from Slovak Hydro-Meteorological Institute, the Operational plan of winter maintenance and dispatcher’s experience. At the present there are 158 road weather stations strategically placed in the Slovak road network (mainly Boschung, Cross, and Vaisala). Some of the RWS are equipped with an overview camera and/or variable massage sign. There are 129 stations located along the highway and motorway network administrated by the NHC, 6 stations located on the Ist class roads administrated by the SRA, and 23 stations located on the IInd and IIIdh class roads in two SGR (15 RWS in Trenčín region and 8 RWS on Slovak-Polish border in Prešov region). Oher regions do not have any road weather stations, so they are not able to monitor the weather on their regional roads. A similar situation is on the Ist class roads, where there are only six full stations and several road sensors. Only a few stations are on main urban roads.

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Slovak Hydro-Meteorological Institute (SHMI) collects weather data from about 100 climatological stations (27 stations are integrated to the synoptic station network) and about 600 rain gauge stations. Output data are: an air temperature, atmospheric precipitation - rain and snow, atmospheric pressure, humidity, wind speed and direction. SHMI provides also graphic outputs of meteorological satellites (air mass), which are updated once an hour and graphic outputs of radars, which are updated once an hour (rainfall) or once in 5 minutes (radiolocation reflectivity). SHMI provides weather forecast and outputs from numeric weather forecast models: x ALADIN - model for short-range weather forecast (12-72 hours), x European Center for Medium Range Weather Forecasting (ECMWF) – model for medium-range weather forecast (72 – 240 hours), x Integrated Nowcasting through Comprehensive Analysis (INCA) system – model for now-casting (2 hours) and very short-range weather forecast (12 hours) in size 1 km in horizontal direction and approximately 100 m in vertical direction. 3.5. Software support for dispatchers Currently in the Slovak Republic there is no national Road weather information system. There are only two relatively simple independent RWIS systems in two regional dispatching’s implemented to measure road and weather conditions on roads and transmit this information to the maintenance centres. The automatic collected and processed date from the RWS located on regional IInd and IIIrd class roads (Trenčin region and Prešov region) are transmitted to the RWIS of competent regional centre without gathering them in central database. Historical and current data as well as early warnings are visualized on the map, in tables and graphs. Additional RWIS system is administered by the SRA. Date from the RWS and road sensors located on the Ist class roads are transmitted to this system and there are shared for the competent regional maintenance dispatching’s, which are responsible for winter maintenance. Road weather stations

b

a Local maintenance centres of NHC SHMI Central system of NHC

Road weather forecasts Fig. 2. (a) Scheme of central RWIS of the NHC; (b) presentation system Bormaweb.

The RWIS at a higher level is administrated by the NHC. Date from the RWS located in highways and motorways network are transmitted to the local maintenance centres and gathering them in a central system of the NHC – Figure 2. All collected data are visualized by presentation system Bormaweb (shown in Figure 2) and shared


for all 14 local centres for dispatchers. Data about local road weather and surface conditions from RWS, additional weather information from SHMI, and road weather forecasts from a statewide contract are used by dispatchers to make a decision on deploying maintenance crews and determining appropriate pavement treatments. GPS data are not included in a central system of NHC. 4. Implementation concept of intelligent winter road maintenance system in Slovak condition The basis of intelligent winter road maintenance management is the central Road Weather Information System (central RWIS) on national level. The vision of central RWIS is to have a robust system that provides stakeholders useful information about road weather conditions around the entire state of the Slovak Republic using several of existing and next generation technologies. This system has to be opened and interoperable system, which can be able to expand and share functions and information with other system of National System of Transport Information (NSTI) for the Slovak Republic, which however is only being built. The central RWIS has to ensure central collecting and archiving of all relevant data from all available sources (RWS, cameras, AVLS, SHMI, other systems of NSTI, mobile weather data, and others) and using the data for subsequent processing and utilization – for example within MDSS, within evaluation process, for purposes of reports of performed maintenance and others. The system has to be designed for regular transmission of all road weather data and forecast as well as performed maintenance data from around the state and for sharing the data with all complementary applications (internal and external) for the end-users. Comprehensive overview of historical, current and future weather situation on the roads as well as vehicle monitoring in real time should be clearly visualized in graphs, tables and maps – available for all authorized users (dispatchers, contractors, administrators, and other stakeholders) under one domain. The Maintenance Decision Support System comprising the road weather forecast module and treatment recommendation module should be internal part of central RWIS. Data which are relevant for the public will be provided via the Winter Information Service. Warnings for drivers will be shown by variable message signs (VMS) directly from RWS or from centre. Development of a central RWIS in the Slovak Republic assumes to carry out a set of steps: x Establishment of a central data collection and central data warehouse to collecting and archiving of all relevant data from all available sources (see figure 1 and 3). For this purpose the unified communication protocol has to be defined in order to standardize the data exchange and allow the data integration into a central database. x Collection of all data from the existing RWIS (RWIS of NHC, SRA, all SGR) in a central data warehouse. This anticipates creation of the Data Service to ensure the unification of the various communication protocols that are currently used. x Developing of a new RWS sites especially along the Ist class roads and in strategic places on regional and main urban roads to finally establish a network of observation points. Before it is necessary to establish a strategic RWS sites (representative and critical) and RWS configuration on the basis of data about the climate zone, terrain, the importance of road, traffic loading, road section ranking in terms of risk of the frost and others). It is necessary also to establish the location and configuration of anti-icing equipment. x Integration of all CCTV cameras to the central system. x Ensuring the possibility of central controlling of variable message signs, which are at present in the case of warnings for drivers controlled directly by RWS or from local dispatching. x Collection of all data from the existing AVLS in a central data warehouse. As in the case of existing road weather stations it again envisages creation of the Data Service to ensure unification of various communication protocols. The AVLS data in the central system will not only serve for the registration and checking of winter maintenance performance (central diary winter maintenance), but also for evaluation of adequacy of winter maintenance performance based on Winter Maintenance Index and for accurate of forecasts. x Intelligent winter maintenance vehicles preparing. Maintenance vehicles (especially spreaders) to equip with an on-board electronic unit (controlling the operation of ploughing and spreading from the cab), Automatic Vehicle

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x

x x x x

x x x x x x

Location System and other devices for contactless detection of road surface condition and measurement of surface friction (slipperiness) and temperatures in real time. All data together with information from AVLS should be transmitted to the central database. The data will be used within the fleet management system as well as within central information system. Intelligent personal vehicles for inspection routes preparing. Personal vehicles to equip with AVLS and sensors for road meteorological conditions measurements. The data will be used for informing the dispatcher and also as an input into RWIS and MDSS. Ensuring weather data, forecasts and warnings from SHMI, or from other sources. Ensuring mobile road weather data from intelligent vehicles equipped with various meteorological sensors. Thermal mapping initiation. Creation of a web application to visualize all relevant data, warnings and complementary applications for users under one domain, which allow internet access from anywhere, possibly from a mobile phones or tablets (alerts possibility of sending via SMS, e-mail). Implementation of a system MDSS ensuring road weather forecast and recommendations for winter maintenance performance. Implementation of a system for recording and checking of winter maintenance performance, which in addition to data from AVLS will centralize reports from all dispatcher’s (plans for winter maintenance, faults). Implementation of system for evaluating of adequacy of winter maintenance performance based on Winter Maintenance Index. Implementation of surveillance system to monitor the functionality of systems or technologies (e.g. RWS). Implementation of a system of winter intelligence services to ensure information about road weather conditions and warning for public. Integration of central RWIS into the NSTI.

Fig. 3.Simplified proposed functional scheme of the central RWIS in the Slovak Republic.


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A simplified proposed functional scheme of central RWIS shown in Figure 3 can be understood as a functional scheme of intelligent winter road maintenance management at national level. 5. Conclusion Automatic Vehicle Location Systems in winter maintenance vehicles and Road Weather Information System are fundamental components of intelligent winter road maintenance. Presently only several partial separate subsystems, AVLS and simple independent RWIS, exist in the Slovak Republic. Relevant information about the current road weather and mainly about road weather forecast are often missing. It is time to build national central RWIS such as in some neighboring countries of the Slovak Republic, for example in the Austria or newly built national system METIS in the Czech Republic. This central RWIS establishing as an integral part of currently under construction NSTI for the Slovak Republic ensures not only a powerful tool for intelligent management of winter maintenance, but will make the huge step towards an efficient exchange of information that can be shared to more effectively solve transportation issues for all stakeholders. Acknowledgements This contribution/publication is the result of the project implementation: Centre of excellence for systems and services of intelligent transport II., ITMS 26220120050 supported by the Research & Development Operational Programme funded by the ERDF.

"Podporujeme výskumné aktivity na Slovensku/Projekt je spolufinancovaný zo zdrojov EÚ" References [1] Prehľad údajov o sieti cestných komunikácií SR, stav k 1.1.2015. Slovak Road Administration – Road Databank, 2015. Available at http://www.cdb.sk/files/documents/cestna-databanka/vystupy-cdb/2015/ck_vlastnik-spravca_01-01-2015.pdf. [2] T. Pospisek, D. Konecny, Standardization of winter maintenance operations on road network in the Czech Republic: Successful way to keep the relation between budget and quality, PIARC, 14th International Winter Road Congress, Andorra, February 4th – 7th 2014. [3] TP 10/2008, Intelligent transport systems and transport technological devices. MDPT, SR, Bratislava 11/2008. [4] TP 09/2008 Devices, infrastructure and systems of road communications technological equipment. MDPT, SR, Bratislava 11/2008. [5] www.cross.cz.