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  • 1. Adesiyun, Adewole
    et al.
    Bezuglyi, Artem
    Bidnenko, Natalya
    Laszlo, Gaspar
    Golovko, Sergyi
    Kraszewski, Cezary
    Krayushkina, Kateryna
    Kushnir, Olexander
    Kuttah, Dina K
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Niska, Anna
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Sörensen, Gunilla
    Swedish National Road and Transport Research Institute, Traffic and road users, Traffic safety, society and road-user.
    Szpikowski, Miroslaw
    Andrezj, Urbanik
    Voloshyna, Iryna
    Vozniuk, Andrii
    Vyrozhemsky, Valeriy
    Short-term Research Visits2014Report (Other (popular science, discussion, etc.))
  • 2.
    Ahlström, Christer
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Bolling, Anne
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Sörensen, Gunilla
    Swedish National Road and Transport Research Institute, Traffic and road users, Traffic safety, society and road-user.
    Eriksson, Olle
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Andersson, Anders
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Validating speed and road surface realism in VTI driving simulator III2012Report (Other academic)
    Abstract [en]

    New simulator models concerning vibration, noise and graphics have been designed and implemented in the VTI Simulator III. The objective of this study is to validate this simulator in terms of road surface realism. Twenty-four drivers participated in the study and drove the same route both in the simulator and on real roads. Three road sections ranging from very smooth to rather uneven were incorporated in the design. The comparison included the objective driving parameter speed as well as subjective parameters from questionnaires and rating scales (evenness, quietness and comfort level). A road section with five speed limit changes was of particular interest in the analyses. No statistically significant difference could be found between the simulator and the car, neither in the parameter speed (in sections with no speed limit changes) nor in the ratings evenness and quietness. Despite similar speed profiles surrounding the speed limit signs, there was a statistically significant difference between the speed in the car and in the simulator, with more rapid accelerations and decelerations in the simulator. The comfort rating was shown to be higher in the car compared to the simulator, but in both cases the general trend showed higher comfort on smoother roads. These results indicate absolute validity for the ratings evenness and quietness, and for the measure speed, and relative validity for comfort and speed surrounding speed limit signs.

  • 3.
    Alfredsson, Magnus
    et al.
    NCC.
    Karlsson, Robert
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Sjögren, Leif
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Hintze, Staffan
    NCC.
    Johansson, Bo
    NCC.
    Lundström, Robert
    NCC.
    Winnerholt, Tomas
    Trafikverket.
    Funktionskriterier för vägkonstruktioner: Förstudie2010Report (Other academic)
    Abstract [sv]

    Det projekt som här rapporteras har som syfte att identifiera och beskriva de svårigheter och möjligheter som totalentreprenader medför, respektive erbjuder, för alla parter. Målet är att utveckla totalentreprenader på ett sådant sätt att branschens effektivitet ökas. Denna rapport är en förstudie där det studerats vilka krav som byggherren ska ställa på utföraren av en vägkonstruktion i en totalentreprenad med funktionsansvar och hur utföraren ska verifiera kraven. Arbetet har genomförts med medlemmar från olika aktörer i branschen och omfattat främst litteraturstudier och intervjuer. Kunskaper och erfarenheter har sammanställts och analyserats för att slutligen kondenseras ned till ett antal förslag till fortsatt arbete.

    Förstudien har pekat ut ett antal områden som viktiga för att påskynda framtida utveckling av totalentreprenader:

    Terminologi – idag råder viss begreppsförvirring

    Analys av funktionella krav i tidigare projekt

    Trafikantkrav

    Miljökrav

    Utveckling av funktionella krav i samverkan

    Väghållarekonomi

    Regelbetingade begränsningar av funktionella krav

    Uppföljning och underlättande av erfarenhetsackumulering

    Implementering av nya mått och mätmetoder

  • 4.
    Andersson, Arne
    et al.
    AB Previa/ARA miljö.
    Jacobson, Torbjörn
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Persson, Bengt-Olle
    Peab Asfalt.
    Tillsatsmedel i asfalt: påverkan på arbetsmiljö och omgivning (2006-02-06). Slutrapport2006Report (Other academic)
    Abstract [sv]

    Vissa tillsatsmedel upplevs idag som besvärliga för arbetsmiljön vid tillverkning och utläggning av asfaltmassa. Vidstående projekt som finansierats av SBUF och Peab Asfalt AB syftar till att ta fram relevanta fakta om tillsatsmedel och dess hälso- och miljöproblem. Projektet har dels inriktats som en förstudie av vad som hitintills har gjorts inom asfaltmiljöområdet både i Sverige och i utlandet, dels kompletterande fältmätningar vid asfaltläggning av polymermodifierad asfalt. Studien har utförts i samarbete mellan Peab Asfalt AB, VTI och Previa/ARA-miljö.

  • 5.
    Andrén, Peter
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Fyrhjulsmodeller för bestämning av vägojämnhet: dokumentation av verksamhet på VTI 2002-–20112012Report (Other academic)
    Abstract [en]

    In Sweden, longitudinal roughness has been more or less synonymous with the International Roughness Index (IRI). IRI is calculated from a longitudinal profile, and describes the accumulated movement between the wheel and chassis on a quarter-car model. The result is given as this movement divided with the traveled length. In Sweden, the unit millimeters per mere is normally used. The IRI-model is only affected by movements in the vertical direction, and the speed is fixed to 80 km/h. This report presents the work to make a full-car model, with the aim to produce a more realistic view of the movements of a vehicle traveling on a normal road. The benefits with a more realistic vehicle model is that indices with a higher correlation to drivers’ and passengers’ experiences can be made. It should be mentioned that a relatively high correlation between IRI and drivers’ estimates road condition has been shown. A FullCar model should, however, give more detailed information about the effect of the road surface on the vehicle. A truck model could, for example, be used to find sections with a dangerous cross fall. A realistic vehicle model could also be used in studies concerning the deterioration of roads, as the road is partly worn by wheel abrasions and partly deformed by contact forces. A simple model could simulate hundreds of thousands of vehicle passages in only a few minutes.

  • 6.
    Andrén, Peter
    et al.
    Datamani.
    Eriksson, Olle
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Lundberg, Thomas
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Prognosmodeller för tillståndsmått i Trafikverkets Pavement Management System: IRI och spårdjup2014Report (Other academic)
    Abstract [en]

    In Sweden, the road surface condition is assessed regularly with laser-based profilographs. This has been done since 1987. All roads are, for financial reasons, not assessed every year, but one way to describe the condition of the entire road network is to work with models. The purpose of these assessments is to provide the Swedish Transport Administration’s Pavement Management System (PMS) with data. The main uses of the PMS are: • To provide a description of the overall road condition and its changes to determine if the selected operation and maintenance strategies are successful, and if an acceptable road standard can be offered. • Support the maintenance planning (prioritization and selection of sections for maintenance). • Support for the choice of maintenance method. • Monitoring of performance of construction or maintenance, for example, functional related contracts. • To support research. The Swedish Transport Administration needs a complete description of the road condition in order to demonstrate to the government and parliament how the mission to maintain the roads is achieved. One way to describe the condition of the entire road network is to work with models that forecast the condition the years when measurements are missing. In the choice between using a global or local model to describe the state of development for IRI (International Roughness Index) and rut depth on individual 100-meter segments, the present report shows that a local model is preferred. The coefficient of determination is not high enough in a global model. Also, the researchers cannot see any consequent pattern in the regression coefficients for the explanatory variables we have tried.

  • 7.
    Antonson, Hans
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes.
    Ahlström, Christer
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Wiklund, Mats
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Blomqvist, Göran
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Mårdh, Selina
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Crash Barriers and Driver Behavior: A Simulator Study2013In: Traffic Injury Prevention, ISSN 1538-9588, E-ISSN 1538-957X, Vol. 14, no 8, p. 874-880Article in journal (Refereed)
    Abstract [en]

    Objective: The study examines how drivers experience a conventional W-beam guardrail (metal crash barrier) along both sides of narrow versus wider roads (single carriageway with 2 lanes) in terms of stress, feelings, and driving patterns and whether subjective experience concurs with the actual driving patterns captured by the quantitative data.

    Methods: The study used different methods to capture data, including the VTI Driving Simulator III (speed and lateral vehicle position) in conjunction with electrocardiogram (ECG) data on heart rate variability (HRV) and questionnaires (oral during driving and written after driving). Eighteen participants-8 men and 10 women-were recruited for the simulator study and the simulator road section was 10 km long.

    Results: Driving speeds increased slightly on the wider road and on the road with a crash barrier, and the lateral driving position was nearer to the road center on the narrower road and on the road with a crash barrier. The HRV data did not indicate that participants experienced greater stress due to road width or due to the presence of a crash barrier. Participant experience captured in the oral questionnaires suggested that road width did not affect driver stress or driving patterns; however, the written questionnaire results supported the simulator data, indicating that a wider road led to increased speed. None of the participants felt that crash barriers made them feel calmer.

    Conclusions: We believe that there is a possibility that the increased speed on roads with crash barriers may be explained by drivers’ sense of increased security. This study demonstrates that an experimental design including experience-based data captured using both a simulator and questionnaires is productive. It also demonstrates that driving simulators can be used to study road features such as crash barriers. It seems more than likely that features such as street lamps, signs, and landscape objects could be tested in this way. © 2013 Copyright Taylor and Francis Group, LLC.

  • 8.
    Arvidsson, Anna K
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Energieffektiv vinterväghållning: val av driftstandardklass2013Conference paper (Other academic)
  • 9.
    Arvidsson, Anna K
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Kostnader för fotgängarskador vs vinterväghållningskostnader2013Conference paper (Other academic)
  • 10.
    Arvidsson, Anna K
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Krav för att förhindra fallolyckor: tekniska egenskapskrav för gator och vägar2017Report (Other academic)
    Abstract [en]

    Since injured pedestrians due to falling contributes to high costs for society, therefore the attribute requirements on a road surface is of great importance for safety. The requirements shall be appropriate for all who are on the surface, this applies to both vehicles, cyclists and pedestrians. This report summarises recent accident studies and the prevailing rules regarding the construction of spaces for pedestrians.

    In addition to these compilations an analysis is done of how common it is that people fall due to, for example, uneven surfaces, kerb-stones or stumble. In 38 percent of the reported accidents that occurred between 2008 and 2015 (82,559), the victims said that the accident happened on a footpath/pavement. To give a good picture of how many accidents that may occur due to surface and paving was 4,443 accidents filtered out, and all the descriptions were read and divided into 12 various categories. The most common reason to a person being injured, according to themselves, was unevenness, holes and pits, level differences or related to the stone/tile surface. The social-economic cost for these 4,443 accidents was in average 845 thousand SEK.

  • 11.
    Arvidsson, Anna K
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    RSI: Road Status Information2013Conference paper (Other academic)
  • 12.
    Arvidsson, Anna K
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Sträckprognoser E62013Report (Other academic)
    Abstract [en]

    Road stretch forecasting is a method for forecasting the weather situations or road conditions, especially slipperiness. This project has been a start on implementing the road stretch forecasting technique on Swedish roads. Road stretch forecasting is already implemented in several parts of the world including Norway and the Czech Republic and is a method for forecasting the weather situations or road conditions on the stretches between the existing Road Weather Information System outstations (RWIS). RWIS outstations are located all over Sweden and mainly in places where there is a high probability of slipperiness. But if the area around the station is changed, for example modifications of the vegetation, the conditions can be changed compared to the original mapping of the road. This leads to a high probability for extreme points in road stretches in between the RWIS outstations. To make a model that describes the road, it is necessary to make a thermal mapping and an analysis of the topoclimate to know the variations in temperature, altitude, shading etcetera, along the road. Then the road is divided into segments representing the different variations of the road. The model calculates the forecast for the road surface temperatures and road conditions, the modelled values are compared and adjusted with the measured temperatures from the thermal mapping. In conclusion, the results regarding this road stretch along E6 show good congruence between the modelled values and the measured temperatures.

  • 13.
    Arvidsson, Anna K
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Sustainability and climate change considerations in winter maintenance2015Conference paper (Other academic)
  • 14.
    Arvidsson, Anna K
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Tekniker och metoder för mer energieffektiv vinterväghållning2011Report (Other academic)
    Abstract [en]

    One important question in winter road maintenance is: How can we make winter road maintenance more energy efficient? There are several factors that can affect how, when and where the winter road maintenance is performed.

    A RWIS outstation (Road Weather Information System) measures the road weather on the road and close to the road, it measures many parameters, such as road surface temperature, air temperature, relative humidity, precipitation type and amount, wind speed and direction. Measured parameters together with weather forecasts make it possible to determine when and where the action is needed. Thereafter it is time to make a route planning to ensure that the correct action is done on the right place at the right time, and with the best suited equipment for the winter road maintenance.

    Spreading of salt/sand could be more efficient by using different computer programs that calculate the needed amount. Also the location of the salt/sand storage affects the driving distances i.e. the fuel consumption.

    One of the factors that account for the greatest uncertainty in terms of winter road maintenance is the weather. An area that has a need for more research is how future climate changes will affect the winter maintenance.

  • 15.
    Arvidsson, Anna K.
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Tema Vintermodell: kalibrering och vidareutveckling av Vintermodellen2014Report (Other academic)
    Abstract [en]

    The project “Winter Model” started at the beginning of the 2000s. The idea was to try and predict consequences of different winter maintenance strategies so that socio-economic costs could be calculated. Using the Winter Model programme, developed during the project, it is now possible to calculate and validate the impact of different winter maintenance measures have on road users, road authorities and local communities. This report contains results of the first complete Winter Model calculations using existing conditions. The report also contains an account of further developments made in connection with this study within the Winter Model. In order to determine what effect changes to road classification standards have on socio-economic costs, the report includes seven comparisons of different application runs. Road classification standards determine how much snow should fall before an action is initiated and/or how long it should take until the action is completed.

  • 16.
    Arvidsson, Anna K.
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Tema Vintermodell: val av standardklass på vinterväghållning med hänsyn till energieffektivitet2015Report (Other academic)
    Abstract [en]

    The Winter Model has been developed within a project called The Winter Model. The aim of the project, which started in the early 2000s, was to assess social and economic consequences of different winter maintenance strategies for road users, road authorities and local communities. The aim of this study was to calculate the change in fuel consumption when the winter maintenance classification standard is lowered on the road i.e. response times and start criterion is increased. Within this project, the fuel consumption model was refined and can now take into account how fuel consumption is affected by the amount of water or snow in the ruts on the road. During the project, six scenario runs were carried out for a 100 km long road section located in Sweden’s central climatic zone. Weather data was obtained from the winter season 2006–2007. Winter maintenance classification standards, and traffic flow volumes were varied during the scenario runs. In one scenario run, the winter maintenance classification standard was lowered from Standard Class 1 to Standard Class 2. This increased the allowable time to carry out the maintenance action from 2 hours to 3 hours – applicable to a Standard Class 1 road, salted, and with a traffic volume of 16,000 vehicles. Comparisons indicate a 1,100 litre reduction in total fuel consumption and maintenance costs was reduced by 5%.

  • 17.
    Arvidsson, Anna K
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    The Winter Model: A new way to calculate socio-economic costs depending on winter maintenance strategy2017In: Cold Regions Science and Technology, ISSN 0165-232X, E-ISSN 1872-7441, Vol. 136, p. 30-36Article in journal (Refereed)
    Abstract [en]

    The project “Winter Model” started at the beginning of the 2000s. The idea was to try and predict the consequences of different winter maintenance strategies and to calculate the associated socio-economic costs. It is now possible to calculate and validate the impact that different winter maintenance measures have on road users, road authorities and local communities.

    This paper contains results of the first complete Winter Model calculations using existing conditions. Comparisons with different road classification standards have been carried out in order to determine the effect they have on socio-economic costs. Road classification standards dictate how much snow should fall before a maintenance action is initiated and how long it should take until the action is completed. Socio-economic costs increased for all comparisons when reductions in the classification standard were applied. As an example of how costs can vary: the scenario is a salted road using a combined plough and salt spreader where the allowed time to complete the action is 4 h that is changed to an unsalted road with an allowed time to complete the action of 5 h. Both scenarios have an action start criteria of 2 cm deep snow, and an annual average daily traffic flow of 2000.

    Comparison results show that the change from salted to unsalted road saves the most cost due to a reduction in salt use and required actions. However, the increased time to complete the action will result in slightly longer travel times and accident costs will increase by 24.2%. The extended action hour affect fuel consumption in a positive way, for example, consumption decreases slightly due to driving more often at lower speeds on unclear roads. By lowering the road classification standard like in this example, total socio-economic costs increased by 3.5%.

  • 18.
    Arvidsson, Anna K
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    The Winter Model: Socio-Economic Cost Calculations for the Future2016In: Routes/Roads, ISSN 0004-556X, no 369, p. 48-55Article in journal (Refereed)
  • 19.
    Arvidsson, Anna K
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    The winter model: Socio-economic cost calculations for the future2015In: Proceedings of 25th World Road Congress / [ed] PIARC, 2015Conference paper (Other academic)
    Abstract [en]

    The project “Winter Model” started at the beginning of the 2000s. The idea was to try and predict the consequences of different winter maintenance strategies and to calculate the associated socio-economic costs. It is now possible to calculate and validate the impact that different winter maintenance measures have on road users, road authorities and local communities. This paper contains results of the first complete Winter Model calculations using existing conditions. Comparisons with different road classification standards have been carried out in order to determine the effect they have on socio-economic costs. Road classification standards dictate how much snow should fall before a maintenance action is initiated and how long it should take until the action is completed. Socio-economic costs increased for all comparisons when reductions in the classification standard were applied. Accident costs consistently accounted for the largest cost increases in all of the comparisons. Current climate change impact scenarios for northern Europe predict an increase in temperature and precipitation, especially during the winter seasons. Some attempts have been made to use the Winter Model for comparisons between different winters, for example variations in weather patterns. These attempts tried to calculate winter maintenance and socio-economic costs for future winter seasons.

  • 20.
    Arvidsson, Anna K
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Vintermodellen 2018: uppdatering av Olycksmodellen inklusive uppdateringar av värderingar till ASEK 6.12018Report (Other academic)
    Abstract [en]

    This report is a compilation of the work done of recalculating the relations/connections for accident risks and their distribution on different winter road conditions in different climate zones. These accident risks are based on accidents having occurred between the years 2007 and 2017. In this project, an update of the accident assessments has been made according to ASEK 6.1 (analysis method and socioeconomic calculation values for the transport sector) Due to this change, the Swedish Transport Administration has changed the valuation of road traffic accidents with accident consequences according to Strada (Swedish Traffic Accident Data Acquisition), instead of consequences as reported by police reports. The new update of the Accident Model has updated accident risks, accident distributions and accident consequences and seems to be realistic and the program is working in a correct way.

  • 21.
    Arvidsson, Anna K.
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Winter Management Systems…: eller finns det andra versioner av Vintermodellen? En översikt över befintliga system2014Report (Other academic)
    Abstract [en]

    VTI has developed a model called the Winter Model, a strategic tool to make calculations for the winter road maintenance during the whole winter season and how this affects the societies costs. This report contains a summary of other models used in this area. The report mostly contains brief explanations of some of the existing tactical decision support systems. No strategic models which is used as tools for follow-up on consequences depending on actions taken on the road, level of winter service, and on how a different winter seasons climate affects the economics, could be found. Most countries have developed their own tactical decision support system. These systems are in many cases very similar, and they are generally used for the decision of the best maintenance activity to perform. The model that reminds the most of the Swedish Winter Model is the American MDSS-model, which has approximately the same incoming data. The largest difference is that it is more used in the daily activities and not as a tool to make calculations for the winter road maintenance during the whole winter season and how this in turn affects the societies costs.

  • 22.
    Arvidsson, Anna K
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Blomqvist, Göran
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Erlingsson, Sigurdur
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Hellman, Fredrik
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Jägerbrand, Annika
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Öberg, Gudrun
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Klimatanpassning av vägkonstruktion, drift och underhåll2012Report (Other academic)
    Abstract [en]

    The global climate change is a reality and affecting society and transport systems. Climate change adaptation of transport systems will make the means of transportation more resilient and decrease the risk and magnitude of disruptions. Generally, climate change adaptations in road construction, operation and maintenance will need relatively large changes, but there is a shortage of the specific knowledge required as to what steps need to be taken, when and where, before measures can actually be implemented. Since climate change effects vary among Sweden's climatic zones, the impact of climate change on the road behavior and longevity is extremely difficult to predict. The need for winter maintenance in Sweden will generally decrease due to the warmer climate. Ploughing frequency will probably decrease as well, but preparedness should not be reduced too much since occasions with more extreme instances will increase. In order to succeed in making the road transport system resilient to climate change, we conclude that there is a need to develop more knowledge about the impact on the road infrastructure system as well as the operation and maintenance of the system including how to adapt through different types of variable and flexible climate adaptation measures and the effects of extreme weather events.

  • 23.
    Arvidsson, Anna K
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Blomqvist, Göran
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Öberg, Gudrun
    Swedish National Road and Transport Research Institute, Infrastructure.
    The impact of climate change on the use of anti- and de-icing salt in Sweden2012In: Transportation Research Circular: Winter Maintenance and Surface Transportation Weather, 2012, p. -10Conference paper (Refereed)
    Abstract [en]

    The future needs for winter maintenance will probably be influenced by the climate change in different ways in different parts of the world. As Sweden is a country with several climate zones, the influence of climate change on winter maintenance will therefore differ between regions within the country. To understand the influence of climate change on the future needs of salt consumption in winter maintenance, modeled road weather data were calculated in the IRWIN project (a joint research project through ERA-NET ROAD funded by the 6th Framework Program of the European Commission), where climate change scenarios from ECHAM5 (the fifth generation of the European Centre Hamburg Model general circulation model from the Max-Planck Institute for Meteorology) were combined with field data from the road weather information system in Sweden.

    These modeled road weather data were used in project KLIVIN (the study presented here) in three Swedish regions (Gothenburg, Stockholm, and Sundsvall) and was combined with the Swedish winter severity index in order to calculate the trends of future salt needs. In this study the needs of salt for each of the three investigated regions were calculated in 30-year periods between 1970 and 2100. The results show that salt use related to snowfall will decrease in all three regions, while the salt use related to temperature will increase in the northernmost region (Sundsvall) and show a small decrease in the two other regions (Gothenburg and Stockholm).

  • 24.
    Arvidsson, Anna K
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Bäckström, Andreas
    Svevia.
    Wärme, Mats
    B&M Systemutveckling AB.
    Dynamisk prognosstyrd vintervägdrift: Fas 22018Report (Other academic)
    Abstract [en]

    Unpredictable weather, short time frames and requirements of high quality can make a challenge of the winter road maintenance. The pressure on both operating staff and machine drivers is very high during periods. The road climate can vary greatly within one and the same operating area and there is a need to adjust for these variations to maximise efficiency.

    The project "Dynamic Forecast Controlled Winter Road Maintenance" has been aimed at developing a solution to simplify the handling of data flows from road weather forecasts and simplify decisions for the winter maintenance contractor what actions are needed and where they are needed. This has been done with data from road weather forecast services together with the existing road network in the operating area, the actions have been optimized for the available numbers of vehicles to create dynamic actions for a more productive and sustainable winter road maintenance.

    Two phases of the project have now been completed and the purpose and goal of streamlining operations through interconnected data flows has been achieved. In connection with this, a dynamic forecasting route optimisation product has also been developed. The project showed that using a dynamic forecasting route optimisation, is it possible to carry out the full potential of the decision support systems through automation. The potential of using forecast-based winter road maintenance is great, both for the customers and for the individual operating contractor. The contractor benefits from it in the operational work, improves the working environment and reduces costs. However, environmental impact also decreases, and in the long term, it also reduces the social economic costs of road maintenance. It is important to emphasise that the technology enables the safety factor on the road to not be reduced despite savings of salt and action times.

  • 25.
    Arvidsson, Anna K
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Eriksson, Olle
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Wärme, Mats
    B&M System AB.
    Bäckström, Andreas
    Svevia.
    Dynamic Forecast Controlled Road Maintenance2018Conference paper (Refereed)
  • 26.
    Arvidsson, Anna K.
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Gustavsson, Torbjörn
    Göteborgs universitet / Klimator.
    Bogren, Jörgen
    Göteborgs universitet / Klimator.
    Nya regler för en effektivare vinterväghållning: En förstudie2013Report (Other academic)
    Abstract [en]

    Current winter maintenance costs are approximately 2 billion SEK per annum, but good monitoring tools to ensure that this money is distributed and used effectively are lacking. The purpose of this study was to develop a basis for new regulations for when action is required to maintain good winter road standards and how payment to the entrepreneurs should be regulated to provide a more efficient winter road maintenance. The Swedish Road Weather Information System (RWIS) was introduced as an aid for winter road maintenance in the late 1970s. The service expanded during the next two decades and today comprises of around 800 stations situated around the Swedish state road network. Measurements include air and road surface temperature, wind direction and speed, and precipitation type and amount. Many of the stations are also equipped with cameras that can be used to assess road surface conditions. Together with weather forecasts, information from RWIS stations is used as the main basis for decision making regarding the need for winter road maintenance. The first step in system improvement is to fully understand how the current system operates. This report summarises the broad outlines of how reporting, regulatory frameworks, and reimbursement models work for winter road maintenance. There are a number of relatively new techniques that could be used to optimise winter road maintenance. These new techniques could help produce a more efficient winter road maintenance programme that reduces the cost to society. The technological developments have moved forward in recent years in a number of areas such as the motor vehicle industry and also in non-contact sensors for measuring friction and road surface temperature. This technology can be used in conjunction with RWIS to give a clear indication of when and where maintenance action is required. This could also provide an opportunity to design a decision support system that could assist road maintenance contractors.

  • 27.
    Arvidsson, Anna K
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Lundberg, Thomas
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Test av korrektionstjänst för GPS-mottagare vid vägytemätning2012Report (Other academic)
    Abstract [en]

    An important factor in the inventory of the road network condition is to be able to geographically position the measurement data at the right place with sufficient accuracy.

    In March 2012, the correction service EPOS, used to provide an improved positioning, was shut down. By the commission of the Swedish Transport Administration, VTI has evaluated whether the free correction service EGNOS, operated by ESA, is possible to be used instead. The answer is yes. No systematic differences in the position data could be observed when using the old and the new correction service.

  • 28.
    Arvidsson, Anna K.
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Lundberg, Thomas
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Sjögren, Leif
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Genell, Anders
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Ögren, Mikael
    Göteborgs universitet.
    Åkkvalitet på vinterväg2014Report (Other academic)
    Abstract [en]

    What can be stated in this project is how a winter road is experienced when compared to snow free conditions, primarily with regard to unevenness and noise. Surveys carried out during the project show that it is possible, without too much difficulty, to measure the unevenness of a snow covered road surface. I this report is winter road defined as a snow covered road (around one day after heavy snowfall). Based on survey results, the study shows that the unevenness of section lengths between 0.05 metres and 1.0 metres are most affected by winter road conditions. Unevenness during winter road conditions is approximately five times greater than that experienced during snow free conditions. However, it is impossible to generalise for an entire road network as surface conditions during winter can be extremely variable. It is also possible to see that the surface structure described by the shortest wavelengths investigated, less than 10 millimetres, is smoother on the snow-covered surface. This is one hypothesis and indicates that measurements are reliable. The link between noise and unevenness is related to vehicle speed. The biggest sound difference between winter and summer road conditions, which could be related to the road surface measurements, was at the lower frequency range. Perceived in-car noise levels were between 3 and 6 decibel higher during winter conditions. However, for the higher frequency range the difference in noise levels was opposite - lower levels during winter conditions. A possible explanation for this is that sound may be absorbed by the snow.

  • 29.
    Arvidsson, Anna K
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Wärme, Mats
    B&M system AB.
    Eriksson, Olle
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Bäckström, Andreas
    Svevia.
    Dynamisk prognosstyrd vintervägdrift: Summering av Fas 12017Report (Other academic)
    Abstract [en]

    The task of the winter maintenance operations is to ensure that the roads are accessible and safe to use. In practice, by means of ploughing, sand and salt spreading, keeping the roads free of snow and ice in accordance with the current requirements. Experience in operational winter management is a shortcoming, which is partly due to the more flexible labour market with short contract periods, but also due to the major retirements that have been in recent years. In order for the winter maintenance contractor to maintain and at the same time increase the productivity, it is essential to develop decision support systems.

    There are today several road weather forecast services that can provide qualified support to decisionmakers in winter road maintenance. As a basis, current weather information from the Swedish RWIS-outstations (Road Weather Information System), which is deployed along the state roads, is used. Some services also use data from sensors in cars. The services provide dynamic road conditions forecasts and in some cases even proposals for actions needed for different road sections. They deliver detailed decision-making prognosis that enable high quality decisions for the correct action in the right time at the right place. Perhaps the main advantage of the forecasts is that they clearly show that only parts of the road network need to be addressed and that the surface temperature forecast, in addition to the forecast of the road surface condition, is important input for determining the needed amount of salt.

    Today’s route optimisation program performs optimisations for the shortest time based on the road owner's road classification, that is based on annual average daily traffic. However, road climate may vary considerably within an operating area, and the need to adjust for these variations in order to achieve an increased resource efficiency, can currently only be corrected manually for resource planning, and usually before the winter season starts.

    The purpose of the project is to provide a more dynamic information to create a more productive winter road maintenance with dynamic road conditions information. Integrating data from a road weather forecast service into existing systems, such as a route guidance driver system, would allow the workforce to work significantly more detailed and dynamically, allowing for significant efficiency gains. In the project, an evaluation of a weather service has also been made with regards to which forecast window is suitable to use in the optimization. The project in this first phase can be described as a first attempt to make the systems working together, validate that it is feasible and that results will be reliable routes for the decisionmakers in winter road maintenance.

    The project has shown that a dynamic forecasting route optimisation for preventative salting can improve the environment by reducing emissions from lorries due to shorter driving distances and reduction of salt usage. The work environment for the maintenance vehicle drivers is enhanced by a higher degree of automation, which means it is less to keep track of, resulting in reduced stress at high performance requirements. Better quality in the winter road maintenance also benefits accessibility for the road users.

  • 30.
    Arvidsson, Håkan
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Eriksson, Olle
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Jämförande provning – ballast 2017: micro-Deval och Los Angeles2018Report (Other academic)
    Abstract [en]

    This report shows results, some statistical analysis and precision data for interlaboratory comparison (round robin) in Sweden performed on three materials of aggregate during 2017. The properties that was determined was resistance to wear by wet micro-Deval test (EN 1097-1) and resistance to fragmentation, Los Angeles test (EN1097-2). The number of participating laboratories were for micro- Deval 37 pcs. and for Los Angeles 34 pcs.

    There were three materials used for this comparison, the materials were called F, S and V. They were delivered to the participating laboratories in the grading 8/11 mm and 11/16 mm for each material. The laboratories should then generate the proper analyze fraction of 10/14 mm.

    The average results for micro-Deval were at the range of 6–8 for all of the materials. The standard deviations were also similar (0,43–0,50).

    For Los Angeles there were the average for one of the materials at 12 and for the other two materials the averages were around 26–27. The standard deviations are proportional to the averages.

  • 31.
    Benbow, Emma
    et al.
    TRL.
    Sjögren, Leif
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Bouteldja, Mohamed
    CETE of Lyon.
    Cerezo, Veronique (Contributor)
    IFSTTAR.
    Spielhofer, Roland (Contributor)
    AIT.
    Toolbox, review of functional triggers: Selection of maintenance candidates2013Report (Other academic)
    Abstract [en]

    ToolBox aims at developing a “concept for proper maintenance planning” to assure the selection of adequate maintenance works (“schemes” or “objects”) to make effective use of the maintenance budget, based on available road condition data, to give minimal negative effects on road users, safety for road workers and the environment. This report covers the first phase of the ToolBox findings and development. In chapter 2 there are a discussion on technical parameters and the use of them. This is followed with a listing of available technical parameters in the partner countries, chapter 4. A state of the art covering how selections of maintenance candidates are done in the respective countries follows including a comprehensive reporting of indicators and parameters available. Finally the chapter 6 covers the selection of models that will be used to evaluate the functional performances decided.

  • 32.
    Blissing, Björn
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Körsimulering och visualisering, SIM.
    Bruzelius, Fredrik
    Swedish National Road and Transport Research Institute, Traffic and road users, Körsimulering och visualisering, SIM.
    Eriksson, Olle
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Driver behavior in mixed and virtual reality: a comparative study2016In: Proceedings of the DSC 2016 Europe / [ed] Andras Kemeny, Frédéric Mérienne, Florent Columbet, Stéphane Espié, Paris, France: Driving Simulation Association , 2016, p. 179-186Conference paper (Refereed)
    Abstract [en]

    This paper presents a comparative study of driving behavior when using different virtual reality modes. Test subjects were exposed to mixed, virtual, and real reality using a head mounted display capable of video see-through, while performing a simple driving task. The driving behavior was quantified in steering and acceleration/deceleration activities, divided into local and global components. There was a distinct effect of wearing a head mounted display, which affected all measured variables. Results show that average speed was the most significant difference between mixed and virtual reality, while the steering behavior was consistent between modes. All subjects but one were able to successfully complete the driving task, suggesting that virtual driving could be a potential complement to driving simulators.

  • 33.
    Blissing, Björn
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Driving Simulation and Visualization.
    Bruzelius, Fredrik
    Swedish National Road and Transport Research Institute, Traffic and road users, Driving Simulation and Visualization.
    Eriksson, Olle
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Driver behavior in mixed and virtual reality: A comparative study2017In: Transportation Research Part F: Traffic Psychology and Behaviour, ISSN 1369-8478, E-ISSN 1873-5517Article in journal (Refereed)
    Abstract [en]

    This paper presents a comparative study of driving behavior when using different virtual reality modes. Test subjects were exposed to mixed, virtual, and real reality using a head mounted display capable of video see-through, while performing a simple driving task. The driving behavior was quantified in steering and acceleration/deceleration activities, divided into local and global components. There was a distinct effect of wearing a head mounted display, which affected all measured variables. Results show that average speed was the most significant difference between mixed and virtual reality, while the steering behavior was consistent between modes. All subjects but one were able to successfully complete the driving task, suggesting that virtual driving could be a potential complement to driving simulators.

  • 34.
    Blissing, Björn
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Körsimulering och visualisering, SIM.
    Bruzelius, Fredrik
    Swedish National Road and Transport Research Institute, Traffic and road users, Körsimulering och visualisering, SIM.
    Eriksson, Olle
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Effects of Visual Latency on Vehicle Driving Behavior2016In: ACM Transactions on Applied Perception, ISSN 1544-3558, E-ISSN 1544-3965, Vol. 14, no 1, p. 5:1-5:12Article in journal (Refereed)
    Abstract [en]

    Using mixed reality in vehicles provides a potential alternative to using driving simulators when studying driver-vehicle inter- action. However, virtual reality systems introduce latency in the visual system that may alter driving behavior, which, in turn, results in questionable validity. Previous studies have mainly focused on visual latency as a separate phenomenon. In this work, latency is studied from a task-dependent viewpoint to investigate how participants’ driving behavior changed with increased latency. In this study, the investigation was performed through experiments in which regular drivers were subjected to different levels of visual latency while performing a simple slalom driving task. The drivers’ performances were recorded and evaluated in both lateral and longitudinal directions along with self-assessment questionnaires regarding task performance and difficulty. All participants managed to complete the driving tasks successfully, even under high latency conditions, but were clearly affected by the increased visual latency. The results suggest that drivers compensate for longer latencies by steering more and increasing the safety margins but without reducing their speed.

  • 35.
    Bolling, Anne
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Jansson, Jonas
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Genell, Anders
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation. Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Hjort, Mattias
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Lidström, Mats
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Nordmark, Staffan
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Palmqvist, Göran
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Sehammar, Håkan
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Sjögren, Leif
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Ögren, Mikael
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    SHAKE - an approach for realistic simulation of rough roads in a moving base driving simulator2010In: Trends in driving simulation design and experiments: proceedings of the driving simulation conference Europe 2010, Arcueil: Institut national de recherche sur les transports et leur securite, INRETS , 2010, p. 135-143Conference paper (Refereed)
    Abstract [en]

    With today’s advanced measurement equipment for measuring roads, it is possible to measure road geometry at high precision within a large span of wavelengths. Detailed information about the roads longitudinal and lateral profile, including macro texture, would in theory be sufficient for a realistic reproduction of road induced vibration and noise in a driving simulator. Especially, it would be possible to create a direct connection between the visual information of the road condition and the ride experience, which would increase the level of realism in the simulation. VTI has during three years performed an internal project called SHAKE with the aim to develop and implement models in VTI driving simulator III that use measured road data for generating realistic vibrations and audible road noise connected to the visual impression presented on the projection screen. This has indeed resulted in an more realistic driving experience, and a validation study with test persons driving both in the simulator and in the field has been undertaken. The OpenDRIVE standard is used as a framework for describing the road properties (e.g. visual, vibrations and noise). For this purpose some augumentations to the OpenDRIVE standard had to be made. This paper describes the technical implementations in the driving simulator, along with results from test drives on the implemented road sections

  • 36.
    Bolling, Anne
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Lidström, Mats
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Hjort, Mattias
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Nordmark, Staffan
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Sehammar, Håkan
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Sjögren, Leif
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Genell, Anders
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Sörensen, Gunilla
    Swedish National Road and Transport Research Institute, Traffic and road users, Traffic safety, society and road-user.
    Improving the realism in the VTI driving simulators: Shake final report2012Report (Other academic)
    Abstract [en]

    The Swedish Road and Transport Research Institute (VTI) has three advanced moving base driving simulators. The aim of this project was to develop and implement new models concerning vibration, noise and graphics in order to improve the realism in the simulators. Moreover, a validation study was to be conducted.

    Within the frame of the project the following were achieved:

    • improvement of the tyre/road vibration models,
    • •improvement of the motion system by changing the rotation centre,
    • •improvement of the noise module facilitating reproduction of noise from tyre/road,
    • •synchronization of the impressions from graphics, noise and vibrations caused by the road surface.

    The validity of the models was tested in the VTI Simulator III. Statistical testing of differences between the car and the simulator indicated absolute validity for the subjective ratings of evenness and noise level and the objective measure speed, with the exception of areas surrounding speed limit signs where only relative validity was found. Relative validity was also indicated for the variable overall comfort. The results from the different validations show that the improvements have been successful and the driver in the simulator can now see, hear and feel the sensation of any road surface irregularities exactly when the wheels hit that part of the road. However, several improvements in the simulator models can still be desired.

  • 37.
    Carlson, Annelie
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Karlsson, Robert
    Trafikverket.
    Eriksson, Olle
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Energy use due to traffic and pavement maintenance: the cost effectiveness of reducing rolling resistance2016Report (Other academic)
    Abstract [en]

    There is a potential to reduce energy use of traffic by performing maintenance measures that lower the rolling resistance. However, the overall aim should be to decrease the total energy use in a life cycle perspective, including energy for both traffic and maintenance. When choosing maintenance alternative, it is also of importance to consider the costs involved. Pavement management is focused on keeping wide spread road networks in acceptable condition given certain budget constraints. Therefore, the economic constraints need to be addressed and in the case of choosing a maintenance alternative that reduces total energy, it also has to be cost-efficient in order for it to be performed. The main scope of the research presented in this report is to investigate how road management should act to reduce total energy use of roads, including traffic and maintenance induced energy use, while also taking cost efficiency and the aspect of uncertainty into consideration. The purpose is to enable a better consideration of the total energy used and maintenance cost when managing the road network. The objective is to derive a meaningful instrument for decision making situations such as when selecting and designing maintenance treatments, in which total energy use and maintenance cost is considered. A general method is developed and presented. A criterion, CR, has been identified for how to choose a pavement maintenance strategy in regards to cost and energy efficiency. A cost benefit analysis approach using Benefit to Cost Ratio, BCR, has been adopted. The study indicates that it is difficult to establish a simple rule of thumb. However, the CR-value may be a useful criterion in some circumstances and it is important to have guidelines as decision support where assessments are made of the road surface characteristics, total energy use and maintenance cost and where the different aspects are valued. This is especially important on an object level.

  • 38.
    Edvardsson, Karin
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Lågtrafikerade vägar: en litteraturstudie utifrån nytta, standard, tillstånd, drift och underhåll2013Report (Other academic)
    Abstract [en]

    In all the Nordic countries unbound or thin sealed road surfaces are common. Low traffic volume roads include all roads with a traffic volume of up to 1,000 vehicles per day. Approximately 75% of the total Swedish government administered road network is low volumed. For the municipal road network, the corresponding figure is 70%. In addition, the whole private road network, which is much larger in length than the government and municipal administered road networks together, is low volumed. Low traffic volume roads have low traffic intensity but it may be noted that it is the same people who often use the roads and therefore incur increased operating costs and reduced comfort. In summary, a large amount of literature in the area treats condition measurements and reinforcement, particularly methods for these. However, there is not much research on the actual road network status, degradation models and life cycle costs published. The structural condition of the road is the most critical parameter for the asset value of the low traffic volume road network. Road capacity affects accessibility for freight transports and is therefore of great importance to the forest industry. Degradation of low traffic volume roads is more complex than on heavily trafficked roads where traffic is the most important parameter. At low traffic volume roads, there is a longer time horizon as well as the fact that several parameters, such as the aging, durability, and climate interact. However, the life length of a road increases significantly when the drainage is improved. Operation and maintenance of low traffic volume roads can generally be divided into the four areas; 1) winter operation, 2) management of the functional condition of the road during the period when the ground is free from frost, 3) management of the road's structural condition, and 4) management during the spring thaw period. In the future, a fifth area may be climate adaption, as mentioned in recent EU statements. New technologies for condition measurements will play a major role in maintenance and improvement of the aging of low traffic volume road network. When it comes to low traffic volume roads, it is very difficult to find economic motives to justify a good condition of these roads. However, these roads must have a minimum acceptable standard, a so called "shame limit", which at least allows people to get to and from home/work safely.

  • 39.
    Edvardsson, Karin
    et al.
    Transportstyrelsen.
    Hedström, Ragnar
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Bankonstruktionens egenskaper och deras påverkansgrad på nedbrytningen av spårfunktionen2015Report (Other academic)
    Abstract [en]

    The main objective of the report is to identify the characteristics that influence the degradation; defined as the condition change, of the super- and substructure of the railway construction. The objective is also to rate the degree of influence of these properties as well as give an account for the effect relationships to the extent that this is possible. In Sweden there are currently about 15,000 km of railway, of which 13 600 km are administered by the Swedish Transport Administration. For this railway facility, there is today a lack of overall maintenance strategies that describes how the maintenance should be carried out for optimal cost efficiency. There is therefore a need to improve the ability to assess the condition and predict the future condition development for different track types in a lifetime perspective. First of all, basic knowledge regarding the condition data collected today and a comprehensive identification of the degradation characteristics affecting the railway facility, as well as the degree of their influence and their effect relationship, are needed. Identified degradation properties include such that affect the super- and substructure but does not include switches, ducting, electrical systems, signal systems or telecommunication. To create reliable life cycle cost models, that enable prioritization and planning of maintenance operations in a cost optimal way, focus on the data inputs to the model is required. Many components of the railway system have complex degradation processes. It is also important, when choosing maintenance strategy, to look at the parts that are associated with high costs, where both the cost of operation and frequency of operation are considered. The greatest impact, of the properties assessed to affect the degradation of the railway construction, has traffic load; where both the load and the frequency are of importance. Then follows, in descending order; drainage, the drainage system, degradation of ballast, rails and sleepers, ballast pollution, track geometry (curves and joints), presence of joints, subgrade stability and vehicle characteristics. The project was done as a comparative study, where degradation properties and effect relationships identified through literature studies have been compared with the corresponding results obtained by qualitative studies, i.e. interviews with experts in the field.

  • 40.
    Edvardsson, Karin
    et al.
    Transportstyrelsen.
    Lundberg, Thomas
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Sjögren, Leif
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Objektiv mätmetod för tillståndsbedömning av grusväglag2015Report (Other academic)
    Abstract [en]

    Condition ratings on the gravel road network are of today made subjectively according to the Swedish Transport Administration’s current method description. This project aims to develop a reliable, objective and mobile methodology for continuous measurement of the road surface condition parameters: evenness, loose gravel, dust and cross fall on gravel roads. It also aims to recommend an objective inventory method for evaluating the drainage condition of a gravel road construction. The result shows that the objective condition indicators which best seem to describe the requested functionality on gravel roads are the acceleration measured using a smartphone application as well as macro texture expressed as the mean profile depth MPD and the average laser pulse reflection over the road cross section measured with a laser equipped measurement vehicle. As an objective inventory method for evaluating the drainage condition of a gravel road, measurements of ditches to ensure satisfactory ditch depth, measurements of cross fall, measurements of support strips to ensure absence of road edge overhang that prevent water runoff from the road, and measurements of periodic and/or rapidly proliferating roughness are proposed. Since gravel road condition is rapidly changing during the season, a quick and simplified version of road surface measurements is required if it should be cost effective with these types of measurements on the gravel road network. Using a smartphone with an application for measurements of evenness is a simple and cost effective way to generate up-to-date condition data for the gravel road network. The application could be supplemented with a button to allow the public to report and mark out damages to the road or be connected to the contractor’s GPS-enabled reporting system, used to mark special points of interest, such as sites for frost heave or erosion.

  • 41.
    Ekblad, Jonas
    et al.
    NCC Roads.
    Lundberg, Thomas
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Lundström, Robert
    NCC Roads.
    Texturmätning med vägytemätbil, som indikator för beläggningens friktion2015Report (Other academic)
    Abstract [sv]

    Tillräcklig friktion är en viktig egenskap hos en vägyta. Normal friktionsmätning är omständlig och resurskrävande. Vägytans makrotextur mäts varje år för den större delen av vägnätet. Det skulle därför vara effektivt att använda makrotextur som indikator för nedsatt friktion. I denna rapport studeras sambandet mellan makrotextur och friktion.

    Mätningar utfördes på ett riktat urval av sträckor i Östergötland. Urvalet riktades mot låga makrotextur-värden. På identifierade sträckor mättes friktion (SAAB Friction Tester) och makrotextur (MPD, Mean Profile Depth med vägytemätbil). Makrotextur mättes av 2 olika mätare.

    Resultaten tyder på att det inte finns något tillräckligt starkt samband mellan friktion och MPD för att användas som indikator. Några generella mönster kan dock skönjas. Låg friktion uppträder främst vid låg makrotextur dock är det samtidigt endast en mycket liten del av sträckor med låga MPD som uppvisar nedsatt friktion.

  • 42.
    Eriksson, Jenny
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Traffic Safety and Traffic System.
    Liu, Chengxi
    Swedish National Road and Transport Research Institute, Society, environment and transport, Traffic analysis and logistics.
    Forward, Sonja
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes.
    Forsman, Åsa
    Swedish National Road and Transport Research Institute, Traffic and road users, Traffic Safety and Traffic System.
    Niska, Anna
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Tapani, Andreas
    Swedish National Road and Transport Research Institute, Society, environment and transport, Traffic analysis and logistics.
    Wallén Warner, Henriette
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes.
    Säkerhetseffekten av ökat cyklande: kartläggning av nuläget för att planera för framtiden2017Report (Other academic)
    Abstract [en]

    During the last decades, cycling has been highlighted as a travel mode with many positive qualities. The documents of Swedish national strategy reveal a trend of an increased cycling. At the same time, it is important that the safety of cyclists must be improved so that an increased cycling does not contribute to more injuries and fatalities in accidents. To cope with the increased cycling without compromising the safety, there is fore example, a need for better understanding of the relationship between the cycling flow and the injuries in various traffic environments.

    In this project, three different studies were carried out to understand how the trend of cycling changes over time and how cyclists' injury risk is influenced by the cycling flow and the traffic environment. In the first study, a travel demand model has been developed that includes both mode choice and destination choice for cycling. In the second study, models for cyclists’ injury risks have been developed for different types of accidents and traffic environments. In the third study, interactions between different road users have been observed, to study how these are affected by the level of bicycle flow. Overall, the studies in this project have shown that bicycle flow is an important factor influencing cyclists’ accident risks. Higher bicycle flow corresponds to fewer interactions per cyclist and a lower risk of injury in a single bicycle accident as well as in a collision accident with motorised vehicles. We have also been able to demonstrate that it is possible to model travel choices and destination choice of cyclists and to develop models that describe cyclists’ injury risk. However, to provide better estimates, data with better quality are necessary for the model inputs, especially when it comes to the cycling and the description of cycling infrastructure.

  • 43.
    Eriksson, Jenny
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Trafiksäkerhet och trafiksystem, TST.
    Niska, Anna
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Sörensen, Gunilla
    Swedish National Road and Transport Research Institute, Traffic and road users, Trafiksäkerhet och trafiksystem, TST.
    Gustafsson, Susanne
    Swedish National Road and Transport Research Institute, Traffic and road users, Trafiksäkerhet och trafiksystem, TST. NTF.
    Forsman, Åsa
    Swedish National Road and Transport Research Institute, Traffic and road users, Trafiksäkerhet och trafiksystem, TST.
    Cyklisters hastigheter: Kartläggning, mätningar och observation2017Report (Other academic)
    Abstract [en]

    Many different road users share space on pedestrian and cycle paths, and their speeds may differ greatly. Differences in speed can complicate the interactions between road users which in turn may cause incidents and accidents. The purpose of this project is to enhance the understanding of cycle speeds on the pedestrian and cycle paths and to understand how the cyclists adapt their speed to other road users and to the surrounding environment. Three different data collection methods were used: Previous measurements of cycle speed and flow in three different municipalities, Eskilstuna, Linköping and Stockholm (18 locations); new measurements in Linköping (4 locations) and Stockholm (1 location); and new observation studies of bicycle types at these locations.

    The average speed of cyclists on the paths selected varies between 15–25 kilometer per hour. As expected, the lower average speeds were found in the uphill directions, near intersections and in paths with high pedestrian flow. The higher speeds were found in downhill directions and on commuter routes. No general increase in cyclists’ speed was found between years, neither in mean speed nor in proportion of high-speed cyclists. However, bicycle flow has increased in many of the locations over the years. This implies that the number of cyclists holding a high speed, above 30 kilometer per hour, will be increased, even if the proportion of high-speed cyclists stays the same. This may mistakenly be interpreted as increased mean speed. About 70–95 percent of the road users observed on the pedestrian and cycling paths were cyclists and roughly 5–30 percent were pedestrians. An extremely small proportion were mopeds, 0.2 percent. The comfort bike was the most common type, followed by the trekking bike. The electric and racer bike occurred in all locations, but varied 1–10 percent respectively 1–15 percent. The relationship between the type of bike and the speed claim is not entirely clear, but cyclists on the electrical and racer bikes generally have higher speed claims.

  • 44.
    Eriksson, Louise
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes.
    Ihs, Anita
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Trafikanternas krav på vägars tillstånd: en enkätstudie av förares uppfattning om belagda vägar2010Report (Other academic)
    Abstract [sv]

    In order to get a view on the road surfaces´ condition the Swedish Road Administration (SRA) uses both objective measurement mehods, mainly measurements of rut depth and unevenness, and road user opinions on road condition. The objective measurements show that the road surface condition in general has not changed to any greater extent during the latest years. The road user surveys, however, show that the road users, and not least the professional drivers, have become less satisfied with the operation and maintenance of the roads. To try to understand the cause of this discrepancy it is of interest to closer analyse the road user assessment of road surface condition. The objective of this study has been to study the road users' assessment of road surfaces, and more specifically their assessments of seven damages have been studied: rutting, patching and repairs, cracks, uneven and weak shoulders, potholes, other singular irregularities, widespread unevenness as well as two types of texture (rough and fine texture). The objective was also to obtain an overall picture of how different road categories are perceived as well as to investigate how the acceptance and the perceived occurrence of specific damages contribute to explaining the drivers' general opinion on road surface quality. Finally, also the drivers' opinion on maintenance activities as well as their attitude towards those responsible for the maintenance, i.e. the SRA and the municipalities, were studied.

  • 45.
    Eriksson, Olle
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Känslighetsanalys av en modell för asfaltsdeformation2015Report (Other academic)
    Abstract [en]

    Increased commercial traffic volume, higher axle load limit, more frequent use of wide tyres, and a tendency towards higher tyre pressure have resulted in increased rates of rutting on asphalt pavements. Strain in asphalt pavements, caused by heavy traffic, is described by different models and serves as a basis for rut prediction. Prediction is however problematic because of varying and uncertain conditions. Studying the change in model output for a given change in input helps when trying to understand the importance of a correct input. In this report, it is shown how strain depends on compressibility, axle load, contact pressure, and, in some cases, variation in lateral position. Different variables affect the results in different ways. Results are therefore dependent on the choice of variables and the accounting area. The results, formulated from different perspectives, describe the significance of a variables influence on strain measurement without comparison in any definitive manner.

  • 46.
    Eriksson, Olle
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Olycksrisk vid lokala ojämnheter och andra ytdefekter2014Report (Other academic)
    Abstract [en]

    This study has examined, in particular, the effect road surface “local unevenness” has on traffic accident risk. Effects from other road surface defects were also considered but to a lesser extent. Test results are non-significant when considering if local unevenness has any main effect. Local unevenness has also not been chosen as part of any significant term of higher order. The analysis provides no support that local unevenness influences the risk of accidents. With regards to other variables related to the road or road surface, there is a negative correlation between rut depth and accident risk, and a positive correlation between longitudinal gradient and accident risk. Accident risk varies in correlation with IRI (International roughness index) and the permitted speed limit in a way that implies that risk decreases with higher speed and low IRI, and higher IRI and low speed. The risk increases when both IRI and speed increase. Precipitation information is an example of a variable that has been included in the analysis but is not related to the road or road surface. Data indicates that accident risk is lower in places where heavy rainfall often occurs.

  • 47.
    Eriksson, Olle
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    The new proposed ISO macrotexture standard vs. the old2016Conference paper (Other academic)
  • 48.
    Eriksson, Olle
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Lundberg, Thomas
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    MPD and IRI in the position of large goods vehicles: network measurements2016Report (Other academic)
    Abstract [en]

    Monitoring of the state road network in Sweden includes the longitudinal measurements of International Roughness Index (IRI) and Mean Profile Depth (MPD). This data can be used to predict values associated with rolling resistance, comfort and vehicle wear. The paths of the measurements correspond to the surface contact points of the wheels of a light passenger vehicle. In Sweden, lateral position comparisons made between medium and large goods vehicles show that right wheel track positions are not similar. This applies to larger and wider roads (typical motorways and other wide main roads). Knowledge of the surface conditions (IRI and MPD) at the surface contact points associated with a large goods vehicle would prove to be useful when predicting e.g. rolling resistance for large goods vehicles on entire or local road networks. If these conditions are not measured, it is important to know how they differ from the values in the measured path. Using this knowledge VTI’s measurement vehicle was equipped with two extra texture lasers which were mounted to the right of the ordinary texture laser in the right wheel track. Data was collected on a road network with mixed categories of road standard, from secondary roads to motorways. During the study, differences in IRI and MPD values were analysed. Values corresponded to the position of light passenger vehicles right wheel paths and two other paths 25 centimetre and 45 centimetre further out to the right (position of medium and large goods vehicles). The possibility of predicting local differences (shorter sections) and average differences was analysed.

  • 49.
    Eriksson, Olle
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Lundberg, Thomas
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    MPD/IRI Transverse Position2015Conference paper (Other academic)
    Abstract [en]

    Road monitoring of the state road network in Sweden includes for the longitudinal measurement of international roughness index (IRI) and mean profile depth (MPD). In Sweden the paths of the longitudinal measurements correspond to the surface contact points between the wheels of a light passenger vehicle. This data can be used to estimate values for friction, rolling resistance, comfort and vehicle wear. Knowledge of the surface condition (IRI and MPD) at the surface contact points associated with a large goods vehicle would prove to be useful when estimating similar values for large goods vehicle on an entire or local road network. If these conditions are not measured, it is important to know how they differ from the measured path.

    In Sweden, lateral position comparisons made between light and heavy vehicles show that left wheel track positions are similar. This applies to larger and wider roads (typical motorways and other wide main roads). Using this knowledge VTI’s measurement vehicle was equipped with two extra texture lasers which were mounted to the right of the ordinary texture laser in the right wheel track. Data was collected on a road network with mixed categories of road standard, from secondary roads to motorways.

    In this talk, we will present a study of the differences of IRI and MPD corresponding to the position of light vehicles right wheel path with two other paths, 25 and 45 cm further out to the right (position of large goods vehicles). We also will discuss the possibility to predict the differences between the tracks. A statistical analysis procedure for calculating the mean difference and an error margin is suggested. The results showed that although it is very difficult to explain or predict local differences, average differences can be estimated.

  • 50.
    Erlingsson, Sigurdur
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Said, Safwat
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    McGarvey, Terry
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Influence of heavy traffic lateral wander on pavement deterioration2012In: EPAM 2012: Malmö, Sweden, 5–7 September : 4th European pavement and asset management conference, Linköping: Statens väg- och transportforskningsinstitut, 2012, , p. 11Conference paper (Other academic)
    Abstract [en]

    Lateral wander of the traffic has an impact on the degradation development of pavements. This is usually not accounted for in the structural design process. Facilities with wide carriageways and broad shoulders tends to have relatively large lateral spreading while narrow road facilities lacking any shoulders can have highly channelized traffic pattern. In this research lateral wander characteristics have been measured for different road facilities. They can be assumed follow a normal distribution where the standard deviation describes their lateral spreading. Rut depth has thereafter been estimated according to two new rutting calculation scheme where lateral wander characteristics has been taken into account. The first approach is based on a two step mechanistic empirical (M-E) evaluation of the permanent strain in all layer of the structure and using a time hardening approach to sum up for all wander locations. This has thereafter been used to estimate the difference in rutting development as a function of the standard deviation. The second approach concentrates on calculating the permanent strain visco-elastically in the bound layers of the structure. Both procedures can be used to estimate the rate of relative deterioration for different road facilities. Based on the same structure the first approach give around 6 % increase in the surface rut as the standard deviation of the lateral wander increases from 10 to 20 cm. The second approach estimates this difference to be around 20 %. The difference between the two approaches are partly explained due to that the first approach estimates the rut based on all layers but the second approach from the bound layers only.

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