PROCEEDINGS OF THE 17TH SIRWEC CONFERENCE, LA MASSANA, ANDORRA
30th JANUARY – 1st FEBRUARY 2014
TOPIC 1: WINTER ROAD FORECASTING TECHNIQUES AND METHODS
In our version, the model uses online measurements from road weather stations (RWS) in the Czech Republic and weather forecasts from ALADIN, the operational numerical weather prediction model of the Czech Hydrometeorological Institute. The METRo model was quasi-operationally tested during the winter season (November 2012 February 2013) using data from 25 RWS. We compared three model runs with an emphasis on road surface temperature. The first run used the original model and served as a reference. The second run applied model output statistics (MOS) to ALADIN forecasts of temperature and humidity at 2 m above the ground, which are required by METRo. The third run applied METRo in a nowcasting mode by starting the model every hour and using new measurements available from the RWS. The results indicated that MOS improved the accuracy of the temperature and humidity at 2 m but had little impact on the forecasted road surface temperature. However, the nowcasting scheme significantly improved the accuracy of the forecasts for the initial three to four hours. The evaluation of the METRo results suggests that the radiation flux forecast is crucial for an accurate road surface temperature forecast.
Each upgrade is detailed described in the paper and interesting tests with results are presented. With the new user defined inputs it is possible to significantly influence the road surface temperature forecasts and achieve better results with more realistic anthropogenic flux and depth of the subsurface temperature sensor values. Sun-shadow algorithm was developed and verified with the sensor measurements at the selected locations. Inputs to this algorithm are: geographic location of the road weather station (latitude and longitude), date and time (UTC) and digital terrain/elevation model (DEM) for the wide area of the road weather station location. Results shows great improvement of the METRo predictions when using the sun-shadow algorithm especially in the time period between noon and evening.
Described upgrades were done within the Eurostars project called METRoSTAT. The main goal of the METRoSTAT project is to develop a new high resolution web-based service for significantly improved road surface temperature and state forecasting.
HARMONIE: AEMET new operational weather prediction model. The roadmap to the mesoscale.
Under the SNAPS project (Snow, Ice and Avalanche Applications) funded by EU Northern Periphery Programme, Vegsyn Consult in Iceland has developed a model to forecast snowdrift on the roads. The model takes into account previous snowfall, temperature evolution and wind speed. Snow cover erodibility (mobility index) is calculated using previous parameters. As an output parameter the model calculates a snowdrift index which is a four-valued number; no drifting, low drifting, moderate drifting and high drifting. The model uses hourly data from NWP models. Also, the developed snowdrift scheme can use real-time AWS observations as an input data. It is possible to run the model for either individual points or bigger grids.
The model scheme is a simplified physical interpretation of commonly known principles related to snowdrift. The model development was supported by empirical observations by traffic cameras. Drifting snow may happen several days after snowfall if wind and temperature conditions are suitable. Snow cover erodibility is at maximum during and immediately after snowfall. All drifting seizes if air temperature rises above 0 C. Wind speed has a major rule for the phenomena because weak wind doesnt get the snow moving. 6 m/s is set as a threshold for the snowdrift, during weaker wind snowdrift doesn’t occur.
The Icelandic Meteorological Office currently delivers a snowdrift forecast to professional users for evaluation. The results are promising although refinement in the physical interpretation of e.g. the snow cover history is foreseen. Likewise, the Finnish Meteorological Institute has included the snowdrift scheme into their road weather model, enabling snowdrift forecasts for all over
as colour coded forecast maps.
Interactive Webgis System for Weather Forecasting in Spanish Roads
I. Villarino, N. Garrido, D. Cubero, V. Palacios, J.A. Garcia-Moya
So far, thermal fingerprints were either used directly to identify the susceptibility to ice occurrence of routes, or as an input to forecast road surface temperature with physical numerical models. These models are based on an energy balance description, and needs an accurate knowledge of both meteorological and road parameters.
The objective of this work is to present how an approach based on multivariate data analysis was implemented to thermal mapping. The objective was to gather a given number of thermal fingerprints, with road surface temperature and air temperature at least, and in weather conditions representative of winter. Then data was processed through partial least-squared regression to establish a statistical forecast model for road surface temperature. Results obtained on a whole route provided a forecast with an error similar to the one of physical numerical model. Its application to specific zones could ease the forecast, reduce computation time, and provide an increasing role to thermal mapping.
Therefore a route based forecast has been developed, based on information about sky view, solar view, road type and local air temperature. In this way a forecast for every road section can be created. This information can be transferred to the gritting machine and used for dynamic gritting or dynamic routing. Currently a dynamic gritting pilot project is going on in cooperation with a governmental road authority.
Skyview is measured by driving with a car, which is very time consuming and expensive. Recently we have explored the possibilities of retrieving skyview data by means of Google Streetview information. A comparison between traditional skyview measurements and the Google Streetview approach will be presented.
Forecasts can be made for different road types and bridges. As Holland is a bicycle country, and cycling becomes more and more common in other countries, another new development is the creation of special forecasts for cycle lanes. Surface temperature measurements in cycle lanes show that the thinner asphalt layer can cause cycle lanes to cool down more rapidly than normal roads. Currently cycle lanes are often treated in the same way as normal roads. However as cycle lanes are often more critical than normal roads, it is very important for the safety aspect to create special cycle way forecasts, especially in black ice cases.
earlier developments in Finland and Norway during the last decade, a method to estimate surface precipitation type (snow, sleet, rainfall) that combines information from weather radar and automated surface observations is described.
The method can be regarded as a three-step process. Firstly quality controlled weather radar data provide an areal description of the precipitation field. This information, updated every six minutes, is used to distinguish precipitation areas. Secondly, a temperature and relative humidity analysis is derived from a network of standard surface automated stations. The analysis takes into account not only surface observations but also terrain height to estimate local vertical gradients in the interpolation process in complex orography. Thirdly, an estimation of surface precipitation type is obtained through an empirical formula that provides the conditional probability of snow as a function of temperature and humidity, given that precipitation is present. The resulting product is presented to end-users in a customized way (GIS, specific visualization tool, etc.).
The presentation will provide details of the evaluation of the empirical formula, originally developed in Finland, compared to a second one that takes into account temperature and surface pressure which might be relevant in mountain regions using a large database of observations recorded in the Mediterranean basin. Moreover, details on processing aspects (surface analysis types) and case studies will be presented as well as a discussion of advantages and limitations compared with other existing techniques such as those based on in-situ surface measurements or polarimetric radar observations.
TOPIC 2: SENSORS AND EQUIPMENT (IN SITU, MOBILE, RWIS)
A Robust, Economical, and Reliable technologies for Monitoring the Road Surface Conditions in South Korea
There have been many researches on the surface detection field. However, many technologies have not been applied for real roadways. In Japan, Serizawa had completed the relevant base technologies in road surface reflection in road lightening and others in 1967, and Imamura developed optical sensor for monitoring the road surface moisture using the reflection flux polarized in 1979. Keiji Fujimura developed the mobile-concept road surface sensor in 1988. In recent days, Isao Yamamoto developed the CCTV-based surface detection sensor. In Europe, there is an active researches on VTTs prototype stereo camera measuring polarization differences. In recent days, stereo vision and polarization imaging are used to apply in the Robot navigation.
But these technologies are currently introduced with high cost, difficulty of operating system in local area and limited reliability. In this regard, our study is aiming at devising a road surface condition detection system with low cost and robust accuracy. This is what we have firmly decided using the video image processing(VIP) technology because of low-cost and fast installation. VIP is expected to help implement the low-cost and high-efficiency detection system. VIP is based on the classification algorithm which discriminates the polarization images clusters by utilizing stereo cameras.
For this purpose, we have proposed the system integration of the Road Weather Information in combination with mobile-based surface detection data. In this paper, we introduce a mobile-based monitoring system installed on a series of service vehicles, capable of acquiring, elaborating and transmitting road surface condition data. And this concept will be upgraded in order to integrate different technologies for the analysis of textures, crack detection, surface details such as grooving, and others.
– Winter Road Conditions
– Bearing Strength
– Pavement Quality
– Air Pollution
FCD (floating car data) from vehicles and road weather information from RWIS together with road weather prediction models makes it possible to determine the road conditions with regards to slipperiness and friction in between the field stations. Another use is to model and forecast the road status according to bearing strength during thaw freezing periods in a detailed and dynamic way. The availability of car data increases the spatial and temporal resolution of the road condition models and it also makes it possible to detect how the car behaves and react not only on weather related surface conditions. By having access to vehicle based data it is also possible to detect such features such as pavement quality along the roads as well as the ambient air quality.
In this research, a multi pixel NIR camera for classification of road status over a 2-dimensional surface has been developed. The goal has been to be create a system capable of detecting and distinguishing different road conditions on several different parts of the road surface.
The resulting product is a NIR camera able to classify and distinguish between different road conditions in several thousands of pixels on the road surface. Images and data from the camera can for example be used to overlay on a visual image to visualize the current road status to an operator or used to calculate friction on different segments of the road. By using cost effective components it is also possible to offer the system to the market at a price similar to the existing single point detectors.
roads and other related infrastructures. Three main techniques will be considered:
Satellite-based radar interferometry and, in particular, the Persistent Scatterer Interferometry technique. This technique, which is sensitive to millimetric displacements, can be used to monitor deformation of roads, bridges and their surroundings. Its wide-area coverage capability (1000 km2 for high-resolution data and 10000 km2 for C-band medium-resolution data) makes it suitable to monitor vast regions.
Ground-based radar interferometry, also known as Ground-based Synthetic Aperture Radar. This is a terrestrial deformation monitoring technique which is very similar to the previous one (it uses the same principle). It can be used to monitor parts of roads that are particular critical, e.g. an active landslide that can potentially affect a major road infrastructure, etc. The main advantage of this technique is its capability to monitor deformation over time with a dense sampling: this make is suitable to support decision-making during emergencies.
Real-aperture-radar. This terrestrial technique can be used to measure and monitor vibration of objects, structures and infrastructures. The most direct application to roads concerns the vibration monitoring of bridges over time.
The paper will provide a brief introduction to each of the three techniques, illustrating examples of applications made by the Institute of Geomatics.
TOPIC 3: DECISION SUPPORT SYSTEMS, ROAD MAINTENANCE, BEST PRACTICES AND USER EXPERIENCE
Road weather data in Finland is based on road weather monitoring stations and road weather cameras. Road weather data collection is made by road weather information system. Data collected is combined in the system with data from weather radars and weather satellites. In addition to observed data and calculated parameters based on data there are shown road weather and rain forecasts in the system.
Customers of road weather information services can be split up road maintenance professionals, road users and service providers of value-added services. Typically road maintenance professionals in this area take care of winter maintenance activities on roads or traffic information services for road users in traffic management centres. Road weather information for road users provided by road authority is focused mostly on traffic safety, traffic fluency and incidents on roads. Increasingly the information for road users is also provided by service providers of value-added services.
Finnish Transport Agency with ELY Centre for Southeast Finland provides road weather information for these customers with various contents. In Finland road weather information user interface with detail information is provided for road maintenance professionals. Road weather and road condition information for road users is available on Finnish Transport Agencys web pages and also for mobile devices. Digitraffic service is used to offer real time and historical data for organizations developing value-added information services. With these different user interfaces and content of information we try to meet expectations of our customers needs.
Advanced Snowplow Information System for the Catalonian DOT
Each snowplow has two sensors: a GPS showing location every 90 seconds, and a Status Signal showing the vehicle state when there is any change (moving, throwing salt, shovel down, system failure, ). This information is received in real time by a communications server and stored in a database.
The traditional fleet IS uses this information via a map application showing the last known gps position for each snowplow, a symbology for the last known state, and a dropdown with all tabular information (machine type, plate, driver, etc). Some advanced systems adds spatial relational gis analysis to get the municipality or the nearest road code but really we cant get more from the data?
The Catalonian DOT Roads Metagraph is designed at scale 1:5.000 for upscaling (planning level), roads catalogue, navigation, and dynamic segmentation; allowing these algorithms to be combined with other land variables to get a more complex scenario building. Thinking of our fleet, contains all the roads and paths where a snowplow can move, so we can go a step further!
A new expert system for snowplow fleet management has been developed using the Metagraph. A real time database listener launches a new process every time a snowplow changes the status and execute advanced gis procedures to determine implicit information: geocode the gps coordinates, calculates the real path on the graph, intersect other geographic information, reference to the graph milestones, and store the results in a new layer on the database.
Advanced analysis were performed to obtain the spatial positions where snowplow state changed. Being time-dependent, the only way to relate over the lineal reference system was changing the routes to the temporal dimension, relating the states via temporal dynamic segmentation, and changing back the result to the spatial dimension.
Thanks to the new system we are able to generate more complex statistics: worked kilometers, average speed, percentage of activity in each state, etc.
Direct applications of the resulting tool are discussed: modeling and understanding existing road configurations under different wind and snowfall conditions, but also predicting the effects of proposed alterations to the road bed and the elements around it. With careful design of embankments both above and beneath the roadbed, it is foreseen that airflow can be canalized in such a way to induce passive snowdrift removal with no need for mechanical intervention under favorable conditions. Techniques include embankment profiling and the addition of fixed aerodynamic elements in order to increase secondary snow transport away from the roadbed and into the adjoining spaces. Their possible application to a real-world scenario in Andorra is presented.
How local weather forecast can save money in snow removal
Our presentation software is designed not only to display data output from the model, but to provide complete data platform for other systems that use these data. It means we are able to prepare other modules/software applications with current forecast data in any form (XML, JSON etc.) to the other users in very short time after the data are available.
Software is able to distribute visualized forecasts to end users in very short time in heterogeneous network environment, with instant impact on decision process in winter maintenance. The data are delivered in context with measured data from each road weather station and forecasts are further validated by currently measured values on hour basis.
This software with current, accurate nowcasts will deliver the basic platform for further more difficult decisions in winter maintenance processes and generate additional data for delivery to Intelligent Transport Systems or to other applications in traffic infrastructure, winter maintenance and public ITS portals to be able to react on changing weather conditions a bit earlier the change actually occurs.
Use of high resolution ensemble forecasting for high impact road weather events
B. Evans, A. Veal
Comparison of non-invasive sensors and road sensors for the usage in section control systems on motorways
A. Rascher, S. Grosanic
Within the German Test Site for Road Weather Stations  various road sensors as well as various non-invasive sensors are installed. The data for both detection technologies has been collected for the last 2 years and allows a statistically valid comparison of them. In this paper the advantage and disadvantage of the two sensor technologies will be shown for the measurements waterfilm thickness, road surface and road temperature. In order to describe the behavior of the sensors, the available data will be analyzed concerning the availability of valid datasets and the accuracy. Additionally the performance of the sensors is examined during periods of different clusters of traffic volumes.
The measurements of waterfilm thickness, road surface and road temperature are very important for automatic traffic control algorithms  as a speed limit caused by rain is derived and shown on variable message signs. In the German Technical Bulletin  a matrix with the two measurements precipitation intensity and water film thickness define which wetness-level is detected. There are 5 wetness-levels which cause different speed limits. For the first supply thresholds are given based on the experiences with road sensors. For the newer non-invasive sensors other thresholds may be necessary. This paper will show some possible thresholds for the precipitation/waterfilm thickness matrix and their effects on the speed limits shown on the variable massage signs.
The paper focuses on the Finnish Meteorological Institutes (FMI) Customer Services current topics relating to road traffic services, and outlining the central functions and services produced for traffic operations. Current activities involve open data and developments of the data-to-intelligence project with the emphasis in improving operational services.
EU INSPIRE directive has recently steered publicly funded data producers towards opening of various atmospheric and marine data sets. In Finland, these information sources also include national road weather observations in real time. Road weather observations can be retrieved in machine-readable form, from the same IT-interface and under the same license than other above mentioned and freely distributed data. Other service developments focus on traffic-related spatiotemporal data as defined by new service concepts. Interdisciplinary project aims to create service concepts, identify and tackle challenges for business, develop the data analysis methods, collect the required data, develop pre-processing methods for the data, and pilot the services. To achieve these, recent work focuses on ICT-architecture and cloud services capable of handling increasing enormous data volumes, also open data, and methods for a road traffic braking distance application.
As ongoing processes, FMI serves both public and contract clients. Services include among others weather for ground traffic and maintenance, marine and aviation weather services, pedestrian slipperiness advisories and various other safety related services for authorities.
This paper explores the difficulties associated with such edge storms by way of a case study of a storm that occurred in Iowa in December 2012. The case study uses information taken from the City of West Des Moines and specifically from their Department of Public Works, which provides winter services for the city. In addition to details of the storm, the lessons learned from handling this particular storm will be detailed and expanded upon.
TOPIC 4: ROAD WEATHER FOR ALL SEASONS, ZONES & CLIMATES
The very same FMI road weather forecasting system is already operationally implemented and piloted on three highway segments in Spain as part of the EU FP7 ITS (Intelligent Transport System) project FOTsis (Field Operational Test on safe, intelligent and sustainable road operation). Model results are post-processed to estimate expected road weather conditions and to issue warnings when adverse weather is anticipated along the highways.
The presentation will provide a general overview of the applicability of FMI road weather forecasting system during the Sochi Winter Olympics and Paralympics, as well as under highly different climatological conditions as piloted under the FOTsis framework in Spain.
The first RWIS was based on specialized forecasts in plain text format distributed in various forms, using dialed link BBS, videotext etc. Since the demand for fresh information was intense, the final distribution schedule was based on 4 nowcasting form forecasts in 24 hours for regions, highway paths and also road networks in large cities (Prague in particular). Later the implementation of internet based information system allowed presentation of other products as rainfall radar, satellite images etc. Last but not least the GIS based RWIS systems were implemented.
The road weather stations in the Czech Republic are supplied by 5 major providers. However there was a strong need to nationwide interpretation of the road weather station data. This was possible after application of the unified data format for road weather data and storing and managing the data on dedicated data servers. This was a basic condition for further development of online GIS based RWIS.
Currently the text based information is converted into XML format enabling much more flexible interpretation of the information. A very popular product is the forecast of the road maintenance intensity for the next 3 days.
Another improvement of the RWIS in terms of accuracy was implementing of various forecasting models as Icebreak of the Forecaster Controller module. Recently the products of the METROCZ model optimized for the Czech Republic are being utilized. This project is a result of mutual co-operation between CHMI and UFA AV CR.
At present the forecasting centres are using data in BUFR and SH70 formats. The data are presented in sophisticated system Visual Weather (VW). This flexible system allows the forecaster to produce variable outputs from road weather stations. Moreover VW is perfect for implementing different data layers for instance outputs from the METROCZ model.
When northerly moist flows impinge on the Pyrenees, precipitating systems mainly affect the North Slope of the Pyrenees and nearby areas due to orographic blocking. However, under particular atmospheric conditions, the moist flow cross over the mountain range and heavy precipitation can affect an extended area. These events are also associated to lower temperatures than average which in the cold season favour heavy snowfalls in the populated valley of Andorra and highly affecting their road conditions. The challenge comes down to the difficulty that atmospheric models have in forecasting the regional effects of these events over a small mountainous area and how far over the southern side of the Pyrenees range will precipitation spread (extension and altitude).
Four different episodes have been selected to assess the performance of the WRF model (Weather Research and Forecast model) with particular emphasis on the precipitation field. The main goal is to analyse the interaction of the northerly flows with this mountain range, their associated effects and detect the features which could be crucial for operational forecasting.
Until March 2013, six debris flows, eleven debris floods and four rockfalls (two were large boulder falls, 55 and 18 m3) were recorded at the Rebaixader site. The analysis of ground vibration signal, recorded as impulses per second, allowed to define preliminary thresholds for distinguishing between debris flows, debris floods and rockfalls. For example, rockfalls typically are characterized by a short vibration record (< 10 sec) with a peak of vibration greater than 100 imp/sec. The identification of processes was checked by the analysis of the video images and the post-event field evidences. Field surveys, ground vibration acquired at geophones and the movies recorded at the video camera provided unique information on the rapid landslides occurrence and dynamics, and gave an excellent opportunity to show the importance of monitored data for calibrating of simulation models. On the other hand, the monitoring results show that the data gathered by the geophones provides valuable information for the design of alarm systems for the event detection and distinction between processes. Hide Abstract
The high resolution variables provided by the numerical models are used to generate good initial conditions for Model of the Environment and Temperature of Roads (METRo) to forecast the local road temperature and condition. This road model was selected for its robustness and the possibility of adaptation, since its open source code and allows to change the code to add new features and integrate all the information. Apart of the variables calculated by the METRo model, its also useful for road users and administrators to have information about visibility, hail and precipitation type. This will be achieved adding some additional information:
a) Fog forecasts. Calculated using the 1D model COBEL which is able to run well simulate the boundary layer, as it uses a high resolution vertical levels.
b) The hail diagnostic and forecast. Calculated using a combination of numerical models and radar reflectivity data.
c) Surface precipitation type. Calculated from radar, Automatic Weather Station and model outputs.
The system output, designed specifically for the SMC road forecast users, is a web page containing maps, reports and graphics with the most relevant information from each model. Some study cases will be presented choosing roads located in zones prone to have problems related to snow, ice or visibility to check the skills of the system.
Not only are high mountain areas exposed, but also 6 population clusters and 3 main roads. On the roads with which this paper is concerned, a combination of temporary and permanent protective measures is applied. Over a total of 31,5 kilometers there is a total of 82 avalanche prone areas (affecting 63 % of the road), of which 32 present at least a yearly frequency. Most of the slopes affecting the road are south faces, with elevations between 1600 and 2300 meters.
Until the year 2003, the risk on the road was handled on the basis of the regional avalanche danger advisory. In the winter of 2003/2004, a local forecasting system was set up. In order to do so, a snow and weather observation network was implemented and a specific danger scale -adapted to the needs of the handling of the road- was developed. In the winter of 2008/2009, a helicopter based triggering system has been set up, using the Daisybell device.
The implementation of a local forecasting system has represented an improvement of the traffic flux and of the safety of the road. Three times a week or daily in high risk cases, a quick visual interpretation bulletin is made. A specific avalanche danger scale has been designed, including such factors as the probability of occurrence and the size of the avalanches. On the basis of these parameters, a 4-level danger scale has been created: Low, Medium, High or Very High. Only natural danger is taken into account, accidental danger is not considered.
The Daisybell triggering protocol has proved useful whenever: a) triggering can take place immediately after the snowfall; b) the wind during the snowfall has not been too strong. A rigorous shooting protocol has been established, since the avalanche areas are located at the area of influence of Baqueira-Beret ski resort and they constitute important off-piste areas. All the concerned entities are involved in this protocol: the Catalonian road service, the Aranese SAR service (Pompièrs dAran), Baqueira-Beret ski resort and the Catalonian Police Department, as well as the owners of private businesses located in the area.
Three times a week or daily in high risk cases, a quick visual interpretation bulletin is made.
Close collaboration between avalanche forecast center and the responsible managers of the road has made improvements on security management.
According to the results the most important factor of the tested features was screening. The biggest obtained temperature difference between screened and not screened road surface was 13 ºC, which can greatly affect to slipperiness. Especially if screening started on afternoon it caused rapid decrease in temperature. The second important factors were asphalt depth and sloping of the road surface. The significance of these features was much greater on sunny than cloudy days. According to the results, increasing the asphalt depth from two centimeters to six centimeters decreased the temperature variation during 24 hours 2 ºC on a sunny day. On the south faced sloping surface the temperature increase was 0.40 ºC when the slope angle was increased by 1º and on the north faced surface it was -0.46 ºC. Albedo had only a small effect on the road temperature. The biggest difference caused by changing the albedo was only one degree. The simulations of the surface temperatures of the bridge succeeded after small modifications to the model. The biggest temperature difference between bridge simulation and normal simulation was found to be only 1.5 ºC.
In the communication perspective the focus is on the focus is on V2I (Vehicle-to-Infrastructure) communication. The vehicle bypassing the combined RWS/RSU is supplemented wirelessly and automatically with up-to-date road weather related data and services, and at the same time possible vehicle-oriented measurement data is delivered upwards. IEEE 802.11p is the primary communication protocol, but also the traditional Wi-Fi communication is supported. The RWS/RSU is linked with IEEE 802.11p for communication attempting, but it has also internal Wi-Fi modem, and both of these communication channels are actively seeking the bypassing vehicle communication systems. The local server is also gathering measurement data from local measurement entities in the RWS. The data from these sources, together with possible vehicle-oriented data is sorted and further delivered to FMI local facilities through 3G. The advanced services are developed in FMI facilities and delivered back to the RWS/RSU and ultimately to the vehicles.
The services provided to vehicles are two kinds, based on purely measurement data or data analysis. The measurement data provided to vehicle consists of friction, temperature, wind and visibility. The data analysis services are not completed yet, but the expected services are snowdrift forecast and a special type of route weather service tailored for dedicated road stretch.
The distance between cars, called as a safe following distance, should be as long as the vehicle is possible to stop without collision in case of accident or other sudden braking. Suitable safe following distance improves the fluency and safety on the roads but the local weather and road condition should be taken into account, too. Car manufacturers have developed several systems to inform drivers if the distance between cars is too short. Also, there are systems that are automatically keeping the distance between cars long enough or braking also if needed. Those systems are called as autonomous or adaptive cruise control. However, most probably none of those systems take into account the prevailing road condition and weather.
Road surface slipperiness has a strong influence for the length of the braking distances. The braking distance can be several times longer if the road surface is icy compared to if the road surface is dry. Also, speed has a major role for the braking distances; when the speed is doubled the braking distance becomes four times longer.
On Data to Intelligence project (D2I) different traffic related data was combined to produce new innovative products and applications for traffic sector. One of the new applications is intelligent breaking distance application. The application informs driver if the safe following distance is too short and the prevailing friction is taken into account as well. The friction can be calculated by FMIs road weather model or it can be a measurement. This application has been created in a co-operation with different D2I partners. Noptel is the instrument company, Centria takes care of the implementation and Finnish Meteorological Institute has been creating the service and is delivering data for the application.
The IR-system acquires data from multiple sources and visualizes it for the road users. The data sources are vehicles equipped with on-board sensors and CANbus diagnostics, road weather stations (RWS), open-data services like Digitraffic, weather forecasts and local weather stations, respectively. The data is stored to the system server to be processed and analysed. The demonstration platform uses the data to create a visualization of the current road conditions on the map which is displayed in a web browser interface.
The visualization has to be simple and fast enough for the road users to gain understandable information. As in many other RWIS implementations, colours are used to represent the varying road conditions. In addition road weather forecasts as well as RWS data are visualized. Several algorithms have been developed to optimize the amount of the visualized data, still maintaining good resolution.
A programmable data acquisition (DAQ) system for vehicles, equipped with GPS, GPRS and multiple communication interfaces for practically any sensor, has been developed. The DAQ acquires data from road condition sensors and wirelessly transfers the GPS-stamped data to the IR-server.
A road condition classification algorithm, developed by the Luleå University of Technology (LTU), has been implemented in the DAQ software.
A study of C2x-communication between Finnish Meteorological Institutes (FMI) intelligent RWS and by-passing vehicles, both equipped with 802.11p devices, is carried out. The objective of the study is to test the exchange of weather and road condition information. The exchanged data from the by-passing vehicle is used to enhance the accuracy of local weather forecasts. In larger scale, the aim is to deliver real-time data from the IR-system for the weather model development of FMI.
The observations were made on the experimental sections of roads during two winter periods on the site of the federal highway M-4 Don Moscow Novorossiysk.
Experimental works include: the surveillance by video cameras placed on the highway: the collection of videos for the entire winter; the special snow surveys, measurement of the snow height after the blizzards and snowfalls; analysis of data from automatic road weather stations located on the highway. The special attention during observations was paid to condition of road surface during the passage of blizzards and heavy snowfalls.
Experimental road sites have crash barriers with different scheme placements.
Video surveillance during the winter allowed to reveal that the crash barriers have an effect on the snow distribution on the road surface. A large amount of snow is accumulated during blizzards on the road with crash barriers.
Two possible variants of crash barrier works during blizzards were identified. The variants depend on the scheme of snow removal next to the barrier.
At the first variant, a condition of complete removing of crash barrier from snow must be implemented.
In this case crash barrier will work as blow-snow fence. At the second variant, snow is not removed from the crash barrier. So, crash barrier will work as entire, snow accumulation fence.
The process of snow accumulation on the highway was studied on the analysis of the collected video and snow survey results on experimental sites. The schemes of snow deposits for four-lane roads and four rows of crash barriers were updated.
The research has shown that the availability and placement scheme of crash barriers on highways should be considered when planning the snow removal.
For winter season 2013/2014, the fourth generation of national road weather information system has been prepared and launched. It brings many new features which partly react to users demands. The RWIS contains also the latest version of national maintenance decision support system, which provides dispatchers with the road condition and road surface temperature forecast for each 1 km road stretch for up to 12 hours.
In 2013/2014 the MDSS system will expand to last three regions of the Czech Republic and so it will cover the whole country all highways, Ist and IInd class roads. In this winter season it is also expected that the new MDSS module will be introduced, trying to provide dispatchers with the treatment recommendation.
Besides RWIS and MDSS the road authority also put effort to prepare detailed manual of winter maintenance which should help dispatchers to choose the best available technology. It extends the existing documents and legal conditions with further specification of different types of reaction to specific winter road conditions and phenomena dangerous for road traffic. As the direct result, the decision diagram has been produced to be placed on every dispatchers table.
The presented paper is trying to describe the key features of decision support in the Czech Republic, by presenting the information and decision support system and the manual of winter maintenance.
Roads Inundation Simulation using Weather Radar Rainfall in Urban area
As far as the Andorran roads are concerned, which are the main communication routes in the country, its vital for roads managers to be aware of the natural phenomena that affect them, in order to know how to prevent and act to minimize their impact.
Analyzing the historical database of natural hazards based on press news created by the CENMA (Snow and Mountain Research Center of Andorra), between 1933 and 2000 the 5 natural phenomena that have affected more frequently the roads of the country have been rock falls, followed by tree falls, snowfalls, floods and landslides. Concerning the main meteorological phenomena associated (which are often the triggers), there is rain, wind and snow. Talking about fatalities, the most frequent phenomenon is not the one which has caused more victims. Indeed, in this period of study, Andorra has had to lament a total of 19 deaths caused by natural hazards impact on roads, which of 13 have been victims of a single episode of floods in 1982.
That rock falls are the phenomenon that have affected most often Andorran roads, according to press news, seems to be normal in a country with so much elevation, where roads go from about 850 m (border with Spain) to 2,400 m of altitude (Port dEnvalira, near the border with France) in just 40 km. But we must be aware that this database is not exhaustive regarding the impact of natural hazards on the roads, such as, for example, the snowfalls in the country not always appear on press news, whereas they are probably the phenomenon that request more means and dedication from the Andorrans roads managers.
Even if they are not part of the study period (1933-2000), it is worth mentioning several episodes of significant snowfalls suffered by Andorra last winter, causing more than one evacuation of population due to the high risk of avalanche, and a large increase in the cleaning tasks of the country road network. Examples of those important actions taken on the roads have been significant increases in kilometers covered by snow blowers and tons of salt thrown on the roads to minimize frost.
Development of weather tools to forecast adverse road weather in Catalonia
J. Amaro, J. Toda, A. Sairouní
Traffic is an example of this outstanding necessity. In the case of Catalonia, a country with a complex terrain that gives rise to climatological variability, it is necessary to supply precise information about ice, snow, fog, rain, hail and strong wind with the aim to solve the local particularities of each region.
So, for example, while it is essential to provide an accurate gust wind forecast to avoid the risk of overturning trucks in south regions, it is required to have an accurate fog model inland where the lack of visibility causes important collisions. Furthermore, independently to seasonal conditions, the management of intense showers that cause landslides and fast changes in visibility is crucial to avoid dangerous driving situations.
Consequently, the Meteorological Service of Catalonia provides a wide range of products that adapt to the particularities of each region. Among the last developments the 11th day forecasting stands out, thanks to the implementation of ensemble statistical prediction. On the other hand, the accuracy of prediction models with a higher resolution (up to 400 m) ensures the development of products that can simulate local conditions.
All these improvements combined with specific weather models for traffic including variables as fog, hail, visibility and type of precipitation, and with a system of alarms generated from radar information, can allow a better forecasting of adverse phenomena and a substantial benefit to apply management measures and for the activation of emergency plans.
This work has focused on the application and comparison of three methods to determine quantitatively the susceptibility of avalanche triggering on the road to Bonaigua pass (Pallars Sobirà county). 1) By using the analytic hierarchy method, 2) By Geographic Information Systems (GIS) spatial analysis and 3) Based on the multivariate statistical analysis.
Bonaigua pass is located at the northwest corner of the Catalan Pyrenees. Affectation due to avalanches in the road C-28 is a current problem. This infrastructure links Vielha (Val dAran) and Esterri dÀneu (Pallars Sobirà), being the busiest connection between the two regions. The C-28 is the access road to the ski resort of Baqueira Beret, an attraction that in winter significantly increases the number of users of this road. The section considered in the study has a length of 10km.
The study has been based on the analysis and understanding of avalanche terrain. Its aim is to classify the starting zones according to their susceptibility and to implement the results in areas without observational data. The final goal of the study is to help to improve the knowledge of the susceptibility of avalanche triggering in order to prevent and mitigate the consequences of this phenomenon in infrastructures and roads.
The results show how the values obtained from the three methods have a high correlation. In spite of the degree of subjectivity introduced in the process of the analytic hierarchy the results have a good fit with the results of the other two methods. Finally, the GIS analysis and the multivariate statistical analysis require to use observational data, while is not required when applying the analytical hierarchy method.
Lunada Port: Singular example of isolation by road in the XXI century in Spain
BU572 – CA643 is the name of that road and crosses Castro Valnera Massif,in the south leaving the summit of Castro Valnera (1718 m) and in the north Picon del Fraile ( 1625 m).
For a few days of autum and spring and especially during the winter , this road is often closed due to the abundance of precipitation as snow and avalanche danger.
This is the third mountain pass over height of Cantabria , behind the ports of San Glorio ( 1609 m) and Piedraluengas (1354 m) that connect the provinces of León and Palencia with Liébana in the Cantabrian region , through the Picos de Europa Massif.
During the winter of 2012-2013 the Lunada Port closed more than 40 days and the Unit Army of the Air, Air Surveillance Squadron 12th number , with air base at 1600 m elevation in Picón del Fraile was more than 40 days isolated by road.
On February 5 was the last day that could be accessible by land after performing cleaning the road with trucks snow plows and milling . Previously , in 2005 were isolated 28 days.
In the environs , is the Lunada winter resort , the lower sky station at a lower height above sea level in Spain , managed by Detulsa company , due to the accumulation of snow was not able to open access to over many winter days.
In this paper we analyze and study this unique case of heavy snow on relatively low sea level and the influence and snow conditions on the roads and infrastructure in the region.