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  • 1.
    Andersson, Anders
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle Systems and Driving Simulation..
    Blissing, Björn
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle Systems and Driving Simulation..
    Carlsson, Håkan
    Swedish National Road and Transport Research Institute, Infrastructure, Measurement technology and engineering workshop.
    Erlingsson, Sigurdur
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Hellman, Fredrik
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Hjort, Mattias
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle Systems and Driving Simulation..
    Ihs, Anita
    Swedish National Road and Transport Research Institute, Infrastructure.
    Kuttah, Dina K
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Nåbo, Arne
    Swedish National Road and Transport Research Institute, Traffic and road users, Driver and vehicle.
    Thorslund, Birgitta
    Swedish National Road and Transport Research Institute, Traffic and road users, Driver and vehicle.
    Designguide för Smarta gator2022Report (Other academic)
    Abstract [sv]

    Sammanfattningsvis definierar vi i denna guide ’smarta gator’ kort sagt som mångfunktionella, levande, långsamma, ekologiska och flexibla gator. Det övergripande målet med denna guide är följaktligen ”Smarta gator för en hållbar stadsutveckling”.

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  • 2.
    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.

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  • 3.
    Hedström, Ragnar
    et al.
    Swedish National Road and Transport Research Institute.
    Ihs, Anita
    Swedish National Road and Transport Research Institute.
    Sjögren, Leif
    Swedish National Road and Transport Research Institute.
    Funktionsupphandling av väg- och banhållning: problem och möjligheter2005Report (Other academic)
    Abstract [sv]

    The present project has been carried out within the framework of the subject

    "Competitive procurement in the transport sector". Owing to the increase in

    the costs of infrastructure maintenance on roads and railways in recent

    years, there is greater interest in developing new forms of contract. The

    intention of the ongoing process concerning competitive and performance

    oriented procurement is to create the conditions for more effective

    infrastructure maintenance activity. The problem in performance oriented

    procurement is to define relevant performance requirements which are clearly

    linked to the effects for the final users. This requires the performance

    variables to be measured and evaluated with respect to both the division of

    responsibility between contractor and client and also the perspective of the

    travelling public. In the project, a study is made of the possibility of

    using planning models such as the World Bank HDM-4 or other operationally

    available models/tools in the road sector (e.g. the Swedish Road

    Administration's PMS) in pricing measurable "final results" in conjunction

    with performance oriented procurement. One conclusion which is generally

    valid for both HDM-4 and PMS is that the traffic effect models must be

    complemented before they can be fully used for the purpose of pricing

    measurable "final results" in contracts based on performance oriented

    tendering. On the rail side, there is no counterpart to HDM-4 or PMS. The

    performance variables identified during performance oriented procurements for

    rail infrastructure maintenance are train delays, track bed condition (via Q

    and K indices), defect reports and inspection comments. These performance

    variables can be measured, monitored and evaluated in economic terms in the

    relationship between client/contractor and, to some extent, also in relation

    to the final customer, i.e. the travelling public. There is however no model

    available which gives an overall description of the effects of these

    performance variables and the economic consequences which these, in turn,

    have for Banverket and/or society at large. Even though a lot is known with

    regard to performance oriented procurement of infrastructure maintenance,

    several issues remain to be solved in both the road and rail sectors. It is

    therefore essential that continuity for further research should be created in

    this field.

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  • 4.
    Ihs, Anita
    Swedish National Road and Transport Research Institute.
    Effekt av rillning på rullbanors friktionsegenskaper och behov av kemisk halkbekämpning1998Report (Other academic)
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  • 5.
    Ihs, Anita
    Swedish National Road and Transport Research Institute.
    Halkbenägenheten hos olika överbyggnadstyper: en litteraturstudie om inverkan på trafiksäkerhet och vinterväghållning samt en fältstudie på provväg Björsbyn-Sinksundet1998Report (Other academic)
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  • 6.
    Ihs, Anita
    Swedish National Road and Transport Research Institute.
    Test and evaluation of alternative deicing methods and materials in Sweden1998Report (Other academic)
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  • 7.
    Ihs, Anita
    Swedish National Road and Transport Research Institute.
    The influence of road surface condition on traffic safety2005Report (Other academic)
    Abstract [sv]

    During the latest years VTI has carried out research within a project called "The impact of road surface on traffic" on commission by the Swedish National Road Administration (SNRA). The objective of the project is to improve and supplement the road user effect models in the SNRA pavement management system (PMS). Studies have been/are being carried out on the impact of road surface on vehicle speed, ride comfort, fuel consumption, noise properties and safety. The main objective with this study has been to provide new models describing the relation between traffic safety and the road surface condition. In the accident cost model used today the only road surface parameter included is rut depth and only ruts deeper than 10 mm are considered to have any influence on traffic safety. The relation is then linear and the accident cost increases with increasing rut depth. The investigation that has been carried out is based on data from the road surface measurements done by SNRA on the state roads during the period 1992 - 1998 and accidents reported by the police during the same period. Also data on precipitation has been used. Regression analyses have mainly been used. Dependent Y-variable has been accident ratio (accidents/ 100 million axles pair kilometres). Independent X-variables have been rut depth (mm) and/or unevenness given in the measure of unevenness called International Roughness Index (IRI in mm/m). The material has been divided into several different classes such as traffic flow and precipitation classes.

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  • 8.
    Ihs, Anita
    Swedish National Road and Transport Research Institute.
    The influence of road surface condition on traffic safety and ride comfort2005In: Reprint from 6th International Conference on Managing Pavements 19–24 October 2004: Brisbane Convention & Exhibition Centre, Queensland Australia, Linköping: Statens väg- och transportforskningsinstitut, 2005, p. 11-21Conference paper (Other academic)
    Abstract [sv]

    During the most recent years VTI has carried out research within a project called The impact of road surface on traffic on commission by the Swedish National Road Administration (SNRA). Several studies have been carried out within the main project in order to determine the impact of road surface condition on vehicle speed, traffic safety, ride comfort, fuel consumption and noise properties. Two separate studies on traffic safety and ride comfort are presented in this paper.

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  • 9.
    Ihs, Anita
    Swedish National Road and Transport Research Institute.
    The recent trend of development of snow-removal and ice-control technology in Northern Europe2002In: Winter Cities 2002 Aomori: proceedings of Winter Cities Forum, Aomori: Winter Cities 2002 Aomori Executive Committee , 2002, p. 67-78Conference paper (Other academic)
  • 10.
    Ihs, Anita
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Trafikanternas krav på vägars tillstånd: sammanfattande slutrapport2010Report (Other academic)
    Abstract [en]

    The road condition on all state roads is routinely assessed by road surface condition measurements. Surveys among private motorists and professional drivers are also conducted to find out how satisfied or dissatisfied users are with the operation and maintenance of the state´s roads. In short, the correlation between the objective measurements, carried out to assess the road surface condition (or rather, the road condition indicators used) - and road user's opinions are not particularly good. A number of sub-studies have been carried out within this project to provide ideas on how to ask questions about the road condition to obtain the best possible subjective data. The sub-studies also gave impetus to which objective data should be gathered in future to help improve the correlation between subjective and objective data. The sub-studies included a literature study, a focus group study, a questionnaire study and a driving simulator study.

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  • 11.
    Ihs, Anita
    Swedish National Road and Transport Research Institute.
    Vägutrustningars effekt på trafiksäkerhet, tillgänglighet och komfort: en körsimulatorstudie rörande effekten av mittlinje respektive kantstolpar2006Report (Other academic)
    Abstract [sv]

    The background to this project is that the Swedish Road Administration has put forward a suggestion that there should be no centre line on roads with a width less than 6,5 m. Furthermore, the suggestion also is that one should stop cleaning the guide posts on roads equipped with these, i.e. the reflexes on the guide posts will in principle not be functioning during winter and in darkness. To investigate the effect for the road users during driving in darkness of removing the centre line and having guide posts that in principle are not visible in darkness, respectively, a driving simulator study has been carried out. The two above mentioned road types, i.e. an 8 m wide road with/without guide posts and with posted speed limit 90 km/h and a 6 m wide road with/without centre line and with posted speed limit 70 km/h, respectively, have been studied in two separate driving tests. A total of 30 subjects have driven both road types during darkness under conditions corresponding to both dry and wet road surface, alternatively new and worn road markings, i.e. with road markings that are visible on a long distance or only on a short distance. The study showed among other things that when the road markings fulfil the requirements for visibility given in the regulations the speed is only slightly influenced by whether there are guide posts or not. On the other hand, if the visibility of the road markings is poor one uses the visual guidance from the guide posts to be able to drive at a higher speed. In the former case the mean speed was about 2 km/h lower without guide posts while the corresponding speed reduction was about 10 km/h in the latter case. Furthermore, the mean speed was about 6 km/h lower when the road didn't have a centre line than when it had a centre line. The mean speed was the lowest when the road had no centre line and the visibility of the edge line at the same time was poor. The test subjects also "reeled" more across the roadway, consciously or not, when the road didn't have a centre line than when it was provided with a centre line.

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  • 12.
    Ihs, Anita
    Swedish National Road and Transport Research Institute.
    Winter maintenance in Sweden: Compiled for COST 344 "Improvements to Snow and Ice Control on European Roads". Task Group "Best practice", 27 March 20022002Report (Other academic)
    Abstract [sv]

    This report has been compiled for Task group 3: Best practice, within COST

    Action 344. It covers mainly the winter maintenance on the Swedish state

    roads.

    The winter maintenance in the municipalities is only briefly mentioned in

    some

    chapters. The winter maintenance on private roads is not covered at all.

    Contents: 1. Fundamental issues : Climatic conditions, Standards, General

    standards ; 2. Strategic organisation of winter maintenance: General,

    Information provision, Methods, Equipment, Materials, Manpower, training and

    privatisation, Training and education, Privatisation ; 3. Operational

    organisation of winter maintenance: Getting information, Methods, equipment

    and materials for snow control, Methods, equipment and materials for ice

    control, Methods, equipment and materials for special problems, Measurements

    of efficiency ; 4. Information to road users

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  • 13.
    Ihs, Anita
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Andersson, Jan
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Kircher, Katja
    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.
    Trafikanternas krav på vägars tillstånd: en körsimulatorstudie2010Report (Other academic)
    Abstract [sv]

    In order to get a view on the road surface condition the Swedish Road Administration (SRA) uses both objective measurement mehods, mainly measurements of rut depth and unevenness, and road users, opinions on the roads condition. Objective measurements show that road surface condition in general has not changed to any greater extent during the latest years. Road user surveys show, however, that the road users, and not least the professional drivers, have become less satisfied with the operation and maintenace of the roads. To try to understand the cause of this discrepancy it is of interest to closer analyse the road users assessment of road surface condition. The report presents a driving simulator study, which is divided into two experiments. In the first experiment the importance of different impressions, i.e. visual appearance, noise and vibrations, is tested on a road surface with ruts as well as on a road surface with patchings/repairs. The analysis was based on driving data and on the drivers´ opinions on how comfortable and safe, respectively, the road was to drive on. The conclusion from the first experiment was that the visual apppearence alone does not influence speed, but lateral position. Noise has an influence on the variance of speed, and vibration has an influence on the variance of lateral position. Noise and vibration have an influence on speed in interaction with the visual appearance. The results of the drivers´ assessments of comfort and safety show a clear pattern where the visual appearance, the sound and the vibrations separately and in an additional way have an influence on the subjective experience of comfort and safety. In the second experiment eight road surfaces with different road surface conditions (patches, ruts, ruts filled with water, rough texture, unnevenness (two levels), cracks and edge deformations). The eight road surfaces grouped together in three different groups concerning the assessment of comfort and of safety, though not in the exact same way.

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  • 14.
    Ihs, Anita
    et al.
    Swedish National Road and Transport Research Institute.
    Andren, Peter
    Swedish National Road and Transport Research Institute.
    Mård Berggren, Selina
    Swedish National Road and Transport Research Institute.
    Sjögren, Leif
    Swedish National Road and Transport Research Institute.
    Utformning av väg och vägyta för säkerhet, komfort och hälsa: en förstudie2006Report (Other academic)
    Abstract [sv]

    During summer 2002 a special directive about employees' health and security at exposure to risks due to vibrations during work, also called "Physical agents vibration directive" (Directive 2002/44/EC), was adopted by the EC. The member states had until July 6th 2005 to transfer the directive into the national legislation. Certainly the condition of parts of the road network can be such that the vibration levels that professional drivers are exposed to exceed the limits that are given in the vibration directive. VTI has therefore been commissioned to carry out a pilot study including a survey of the responsibility of the Swedish Road Administration (SRA) as well as the interpretation of the directive made by the Swedish Work Environment Authority, but also to study how different designs of the road's longitudinal profile may give rise to vibrations that are harmful or uncomfortable to humans. The present pilot study has included a literature survey concerning vibrations and their influence on humans with particular reference to roads and their design, demonstration measurements of road geometry and vibrations and analyses of these with regard to the directive as well as discussions on suitable measures for health risks or discomfort during travel on road.

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  • 15.
    Ihs, Anita
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure.
    Arvidsson, Catharina
    Swedish National Road and Transport Research Institute.
    Ternström, Hillevi
    Swedish National Road and Transport Research Institute.
    Kartläggning av internationella FoU-program inom InfraSweden2030:s fokusområden2018Report (Other academic)
    Abstract [sv]

    InfraSweden2030 är ett av för närvarande 17 nationella strategiska innovationsprogram (SIP) som finansieras via Vinnova, Energimyndigheten och Formas. InfraSweden2030 är det första nationella programmet i Sverige i sitt slag inom transportinfrastrukturområdet. Programmet möjliggör strategisk innovation genom att koppla ihop väg- och järnvägsteknik med det senaste inom material-, fordons- och kommunikationsteknologi samt standardisering.    Rapporten innehåller en kartläggning av det internationella läget, med störst fokus på Europa, vad gäller liknande program som InfraSweden2030 eller program med bäring på aktiviteterna inom InfraSweden2030. Utifrån kartläggningen innehåller rapporten också några slutsatser och rekommendationer, exempelvis förslag på potentiella samarbetspartners för InfraSweden2030.   Med kartläggningen som underlag ska projektet i sin helhet kunna göra bättre prioriteringar i sin strategiska planering, göra effektivare resursfördelning i programmets satsningar samt att etablera samarbete med liknande program och partners på internationell nivå.

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  • 16.
    Ihs, Anita
    et al.
    Swedish National Road and Transport Research Institute.
    Augdal, Arve
    Störande ljus vid vägarbeten om natten: fältförsök på E6 norr om Varberg 19-20 april 20072008Report (Other academic)
    Abstract [sv]

    In order to avoid disruption in heavy traffic during daytime, road works are carried out to an increasing extent during off-peak hours at night. The requirements on the temporary traffic control are however considerably different in daylight and in darkness to ensure acceptable visual conditions for the road users. A considerable difficulty for the driver who is passing a work zone in darkness is to obtain a visual impression of sufficiently good quality, despite glare from oncoming traffic, work vehicles and work zone illumination. This is required to get a correct impression at which speed to drive and where to place the vehicle during the passage. During night-time the pavements are also often wet or damp, particularly during the winter season, which further increases their reflectivity. The reflections in the pavement may conceal road markings on the road way, contribute to the glare and increase the complexity of the visual information to the driver. This constitutes not only a safety risk for the road user passing the work zone but also for the people who are within the work zone. The risk is that the road user misinterprets/misjudges the information from the temporary traffic control and drives into the work zone. Within NORDFUD it has been decided to carry out an extensive project to investigate how to best avoid problems with glare from different types of road works where work is going on during night-time. This report presents the results from one stage of the project where an expert group has made evaluations of temporary traffic controls for a stationary motorway road works that was set up on a closed part of E6 outside Varberg. The expert group consisted of ten people, most of them coming from the project group. A number of different scenarios, i.e. different combinations of traffic control components, were assessed by the experts while driving past the work zone. The experts made a subjective evaluation of the visual guidance and the degree of glare.

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  • 17.
    Ihs, Anita
    et al.
    Swedish National Road and Transport Research Institute.
    Augdal, Arve
    Sörensen, Kai
    Tiensuu, Antti
    Störande ljus vid vägarbeten om natten: pilotförsök 1 och 2: mötesseparerad landsväg2008Report (Other academic)
    Abstract [sv]

    In order to avoid disturbances in heavy traffic during daytime, road works are carried out to an increasing extent during off-peak hours at night. The demands on the design of the work zone traffic control differ, however, considerably between daylight and darkness in order to achieve visual conditions that are acceptable for the road users. In order for the driver to be able to pass in a safe way the design of the work zone traffic control should not be possible to misunderstand. One requirement is that the visual conditions are good. The latter means that the strength of the total glare from opposing traffic, warning lights, work vehicles and work zone illumination must be limited. During night time the pavements are often wet or damp, particularly during winter time, which increases the reflexion in the pavement. The reflexion can conceal the road markings, alter the colour of the signs and markings, contribute to the glare and increase the complexity of the visual information to the driver. The risk is that the driver then misunderstands/misjudges the information and drives into the work zone. Within NORDFOU it has been decided to carry out a large co-Nordic project to investigate how to best avoid problems with glare and provide a good visual guidance at work zones where work is carried out during night time. The objective of the whole project is to improve the safety both for the road users passing the work zone in the dark and for people working within the work zone, and in particular road works during night time on major roads. Previously, primarily during the year 2005 fore preliminary studies have been carried out within the project concerning yellow running lights, work zone illumination, methods for measuring glare as well as reflexion on various types of pavements. In this report two pilot studies are described, both dealing with stationary road works on "2+1"- roadways, which were carried out during spring and autumn 2006, respectively. The first pilot study was carried out on an airfield outside Copenhagen, Denmark, where a work zone was built up on a runway. Two types of work zone illumination and a number of different variants of running lights (brightness, frequency, sequence, etc.) were tested. All assessments were made by a panel of experts consisting of the members of the project team, who were standing on a fixed distance from the work zone. Pilot study 2 was carried out on a real 2+1 road outside Linköping, Sweden, where a stationary work zone was established on the single lane part of the road. The pilot study included driving tests where the test subjects (drivers) were people older than 50 years. In this way a more realistic situation was obtained where the assessments were done when the test subjects drove past the work zone. The test subjects had to answer a questionnaire, and the speed of their vehicles as well as the speed of the ordinary traffic passing the work zone was registered.

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  • 18.
    Ihs, Anita
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure.
    Bolling, Anne
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Hansson, Lisa
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes.
    Hedström, Ragnar
    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.
    Säkerhet vid väg- och spårarbete: en intervjustudie2014Report (Other academic)
    Abstract [en]

    There are rules and regulations that govern how working environment and safety are considered for road and railway works, but despite this a number of accidents and more or less serious incidents happens every year. To get an idea of how safety and working environment related issues are handled in the procurement, planning and implementation of maintenance activities of roads and railways a limited number of interviews with relevant actors have been performed. Purchasers and project managers at the Swedish Transport Administration (STA), as well as entrepreneurs and a union representative at the union SEKO, were interviewed for both the road and the railway side. For the road side, traffic engineers at STA were also interviewed. Based on the results from the interviews a number of problem areas could be identified, of which some are:

    • Dissemination of information about new regulations to all parties at all levels
    • Unclear procedures for self-monitoring, reporting, action on identified deficiencies, follow up and feedback
    • Inadequate procedures for reporting of accidents and incidents as well as for actions taken, follow up and feedback of these
    • The STA nowadays sets skill requirements instead of requirements on specific education/courses, making it more complicated to ensure that the requirements are met
    • It can be difficult to ensure the competence of temporary staff, mainly at work peaks.
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  • 19.
    Ihs, Anita
    et al.
    Swedish National Road and Transport Research Institute.
    Grudemo, Stefan
    Swedish National Road and Transport Research Institute.
    Wiklund, Mats
    Swedish National Road and Transport Research Institute.
    Vägytans inverkan på körkomforten: bilisters monetära värdering av komfort2004Report (Other academic)
    Abstract [sv]

    The decision support system for the maintenance of paved roads, PMS, of the

    Swedish National Road Administration comprises a number of models for

    estimating the costs of road management authorities, road users and society

    at large. In 1998 VTI was commissioned by the Road Administration to carry

    out a comprehensive project with the objective of revising and augmenting

    these traffic effect models. The project is entitled "Traffic effects of the

    road surface" and has comprised a number of subprojects. The primary aim of

    this study has been to investigate, in a field study, the relationship

    between the roughness of the road surface (expressed in terms of the

    International Roughness Index IRI, with the units mm/m) and the perceived

    driving comfort of motorists, as well as their willingness to pay for

    improved driving comfort. 50 test subjects were asked to drive a car over

    nine 500 m long sections with different surface standards. The mean of the

    measured IRI on these road sections varies from 0.8 mm/m on the smoothest

    section to 10.5 mm/m on the roughest. In conjunction with the investigation,

    the test subjects were interviewed by a test leader. During the interview,

    they were asked which factors are significant for driving comfort and how

    they perceived driving comfort on the different sections. The state/condition

    of the asphalt surfacing was considered to have the greatest significance,

    followed by the car and the behaviour of other road users. Density of traffic

    was considered to have the least significance. The test subjects were also

    asked to say what significance different defects in the surfacing had on

    driving comfort. What is most important for a comfortable car journey is that

    there are no holes/depressions in the surfacing. This is followed by ruts,

    roughness that causes vibrations, and bumps and subsidence. The test subjects

    were asked to make a general assessment of driving comfort on a five-degree

    scale during their drive over the nine sections. A clear relationship was

    found between the assessment that the test subjects made and the measured

    IRI, i.e. the higher the IRI, the worse driving comfort was judged to be.

    The physical impact caused by the different surface standards of the test

    sections was also investigated by placing a dummy equipped with triaxial

    accelerometers in the passenger seat of the car that drove over the test

    sections. The willingness of the test subjects to pay for improved comfort

    associated with the condition of the road surface was also investigated by

    three methods: Stated Preference (Choice) and Contingent Valuation Method

    (driving comfort versus petrol price and trip time). A relatively high

    willingness to pay was obtained, but the methods gave very different results.

    It has therefore been impossible to posit a comfort cost model on the basis

    of these. This requires further studies and development of the methods.

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  • 20.
    Ihs, Anita
    et al.
    Swedish National Road and Transport Research Institute.
    Gustafson, Kent
    Swedish National Road and Transport Research Institute.
    Calcium magnesium acetate (CMA): An alternative deicing agent. A review of the literature1996Report (Other academic)
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  • 21.
    Ihs, Anita
    et al.
    Swedish National Road and Transport Research Institute.
    Gustafson, Kent
    Swedish National Road and Transport Research Institute.
    Dubbkraftens betydelse för vägslitaget: en undersökning i VTIs provvägsmaskin1996Report (Other academic)
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  • 22.
    Ihs, Anita
    et al.
    Swedish National Road and Transport Research Institute.
    Gustafson, Kent
    Swedish National Road and Transport Research Institute.
    Kalciummagnesiumacetat (CMA): ett alternativt halkbekämpningsmedel. Litteraturstudie1996Report (Other academic)
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    FULLTEXT01
  • 23.
    Ihs, Anita
    et al.
    Swedish National Road and Transport Research Institute.
    Gustafson, Kent
    Swedish National Road and Transport Research Institute.
    Test and evaluation of CMA/NaCl mixtures i Sweden1997Report (Other academic)
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    FULLTEXT01
  • 24.
    Ihs, Anita
    et al.
    Swedish National Road and Transport Research Institute.
    Gustafson, Kent
    Swedish National Road and Transport Research Institute.
    Persson, Kerstin
    Swedish National Road and Transport Research Institute.
    Evaluation of CMA/NaCl mixture: Effect on road condition/friction, ice melting capacity, corrosion and effect on concrete1996Report (Other academic)
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    FULLTEXT01
  • 25.
    Ihs, Anita
    et al.
    Swedish National Road and Transport Research Institute.
    Gustafson, Kent
    Swedish National Road and Transport Research Institute.
    Persson, Kerstin
    Swedish National Road and Transport Research Institute.
    Utvärdering av CMA/NaCl-blandning: effekt på väglag/friktion, smältförmåga, korrosion och betongpåverkan1996Report (Other academic)
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    FULLTEXT01
  • 26.
    Ihs, Anita
    et al.
    Swedish National Road and Transport Research Institute.
    Gustafson, Kent
    Swedish National Road and Transport Research Institute.
    Persson, Kerstin
    Swedish National Road and Transport Research Institute.
    Öberg, Gudrun
    Swedish National Road and Transport Research Institute.
    Wretling, Peter
    Swedish National Road and Transport Research Institute.
    Haveriutredning: vinterväghållning1996Report (Other academic)
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    FULLTEXT01
  • 27.
    Ihs, Anita
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Gustafsson, Mika
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Eriksson, Olle
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Wiklund, Mats
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Sjögren, Leif
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Road user effect models: the influence of rut depth on traffic safety2011Report (Other academic)
    Abstract [en]

    There are currently no satisfactory effect models for calculating the consequences and costs for road users of different maintenance strategies. The main problems identified by the Transport/Road Administrations in Finland, Sweden, Norway and Estonia, are the relationship between road surface condition and accidents, the effect of the most important state parameter rut depth on road user costs, as well as the role of road-user costs/effects of a road network that is mostly in good condition. These are problems that must be resolved in order to better justify budget allocation for road maintenance. VTI has therefore on commission by the Finnish Transport Administration and with funding from the other Transport/Road Administrations conducted a study to determine the influence of rut depth effects on the accident risk of road users. Separate analyses were made of data from Sweden, Finland and Norway, respectively. It was assumed that the accident risk also depends on other road condition variables, such as longitudinal unevenness, texture, cross slope, geographic location (country), vehicle flow, climate, weather, etc. A model approach was chosen that could address the impact of all these other road condition variables, and the possible interactions between them, on the accident risk. It was assumed that the relationship between accident risk and rut depth is not necessarily a linear function, why rut depth was divided into several categories. It was also agreed that separate equations should be derived for different speed and AADT (Annual average daily traffic) classes. Rut depth categories, as well as speed and AADT classes were chosen to match each country's strategies for maintenance. The overall conclusion of the analysis is that the data does not support any general rules for a maintenance scheme. There are no results to show that deeper ruts generally tend to increase the accident risk. Nor are there results that show that ruts have the same influence on the accident risk for different AADT classes at a given speed or vice versa. There seems to be at increased risk for ruts ? about 15 mm in the highest speed class, but the results differ between AADT classes and are not similar in adjacent speed classes, making the results difficult to understand and less useful to specify the rules for maintenance. For the Norwegian data this trend can not be seen in the highest speed class (> = 90 km/h), but then this speed class differs from the Swedish and Finnish highest speed classes (> = 110 km/h roads and motorways, respectively).

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  • 28.
    Ihs, Anita
    et al.
    Swedish National Road and Transport Research Institute.
    Magnusson, Georg
    Swedish National Road and Transport Research Institute.
    Betydelsen av olika karakteristika hos beläggningsytan för trafik och omgivning2000Report (Other academic)
    Abstract [sv]

    1998 fick VTI i uppdrag av Vägverket att se över de trafikeffektmodeller som finns i Vägverkets beslutstödssystem för underhåll av belagda vägar, PMS (Pavement Management System), och även göra jämförelser med de modeller och den struktur som används i Världsbankens motsvarighet HDM-4.

    Det kunde konstateras att brister förelåg vad gäller dokumentation av hur modellerna tagits fram, vilka antaganden som gjorts och vilka undersökningar som ligger till grund för dessa. Mot bakgrund av detta utarbetade VTI i samråd med Vägverket en plan för det fortsatta arbetet med att förbättra och komplettera de befintliga trafikeffektmodellerna i PMS.

    1999 startades huvudprojektet ”Vägytans trafikeffekter” i vilket har ingått ett flertal delprojekt. Nedan ges en sammanställning av de delprojekt som genomförts/genomförs under 1999 och 2000.

    Ramverk.

    Vägytans inverkan på trafiksäkerheten

    Planprojekt.

    Körsimulatorstudie av vägytans inverkan på trafiksäkerhet.

    Vägytans inverkan på fordonshastigheten

    Vägytans inverkan på komfort.

    Litteraturstudie.

    Komfortstudie.

    Vägytans inverkan på fordonskostnader.

    Vägytans inverkan på bränsleförbrukning och rullmotstånd.

    Vägytans bulleregenskaper.

    Vägytans inverkan på vinterväghållningen.

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  • 29.
    Ihs, Anita
    et al.
    Swedish National Road and Transport Research Institute.
    Magnusson, Georg
    Swedish National Road and Transport Research Institute.
    The significance of various road surface properties for traffic and surroundings2000Report (Other academic)
    Abstract [en]

    This report lists the impact of various road surface properties on: trafficability, travelling time ; road safety ; comfort ; vehicle wear ; fuel consumption ; travelling, route selection ; freight damage ; tyre-road noise; pollution ; the life length of the road ; winter road maintenance

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    fulltext
  • 30.
    Ihs, Anita
    et al.
    Swedish National Road and Transport Research Institute.
    Möller, Staffan
    Swedish National Road and Transport Research Institute.
    Beräkningsmodell för vinterväghållningskostnader: fördelning av medel till Vägverkets regioner2004Report (Other academic)
    Abstract [sv]

    VTI har i uppdrag av Vägverket att ta fram en ny modell för fördelning

    av medel för vinterväghållningen till Vägverkets sju regioner. Det finns ett

    stort behov av en fördelningsmodell som medger en så rättvis

    medelsfördelning som möjligt till regionerna och som därmed också kan

    innebära ytterligare incitament för regionerna att arbeta för att

    effektivisera och minska sina konstnader för vinterväghållningen. Huvudsyftet

    med projektet har varit att ta fram en procentuell fördelning till regionerna

    av totalt tillgängliga medel för vinterväghållningen.

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  • 31.
    Ihs, Anita
    et al.
    Swedish National Road and Transport Research Institute.
    Möller, Staffan
    Swedish National Road and Transport Research Institute.
    Halkbekämpning vid låga temperaturer: en litteraturstudie samt en utvärdering av väglagsuppföljningarna under vintrarna 1993/94–1996/19672000Report (Other (popular science, discussion, etc.))
    Abstract [sv]

    Syftet med föreliggande studie har varit att genom en litteraturstudie undersöka kunskapsläget vad gäller metoder för halkbekämpning vid låga temperaturer. Dessutom har en utvärdering av väglagsuppföljningarna under vintrarna 1993/94-1996/97 genomförts för att undersöka hur vanligt förekommande halka är och därmed också få en uppfattning om behovet av halkbekämpning vid låga temperaturer.

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  • 32.
    Ihs, Anita
    et al.
    Swedish National Road and Transport Research Institute.
    Sjögren, Leif
    Swedish National Road and Transport Research Institute.
    Blomqvist, Göran
    Swedish National Road and Transport Research Institute.
    Grudemo, Stefan
    Swedish National Road and Transport Research Institute.
    Planning of the road transport system development: A literature review2003Report (Other academic)
    Abstract [sv]

    A large number of persons are killed or seriously injured in road traffic every year, and this is not least a great public health problem. The development of different traffic safety measures is proceeding rapidly, and it is of importance that the knowledge is spread and applied. In order to gain information on the state of the art within the traffic safety area the Swedish National Road Administration (Vägverket) has commissioned universities and research institutes to carry out a number of literature surveys covering different parts of the area. This literature survey concerns the planning of the road transport system development. Since this is a very extensive area to cover, certain limitations have been made. The focus is primarily on investigating the concepts of trafficability, accessibility, environmental impact and traffic safety but also measures and methods used for describing the influence of road surface condition on these.

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  • 33.
    Ihs, Anita
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Sörensen, Kai
    DELTA, Danmark.
    Augdal, Arve
    SINTEF, Norge.
    Tiensuu, Antti
    LiCon-AT, Finland.
    Road works during night: Recommendations for the visual environment2008Report (Other academic)
    Abstract [en]

    Road-works almost always mean a restriction of the space available for the road users and thereby also a reduction of the passability. The passage of road-works is acomplicated situation for the driver and therefore poses high demands on the traffic controls used (signs, channelling devices, etc.).

    To avoid disturbances in dense traffic during daytime road works are to an increasing extent carried out during hours at night when traffic volumes are lower. The requirements on the traffic controls are however considerably different during daylight than during night to provide acceptable visual conditions for the road users.

    A considerable difficulty for the driver who is passing the work zone in the dark is to obtain a visual impression of sufficient quality despite glare from meeting traffic, yellow flashing lights, and work zone illumination. This is required to get a correct comprehension on which speed to hold and where to place the vehicle when passing the work zone.

    Within NordFoU it was decided to carry out a joint Nordic project to investigate how to provide a good visual environment at night time road works and as a part of this how to best avoid/reduce the adverse effects of glare.

    The primary aim of the project was that it should result in recommendations as bases for the improvement and coordination of existing regulations in the Nordic countries by giving:

    − proposals regarding glare limitation

    − proposals for requirements for yellow warning/flashing lights

    − proposals for requirements on work zone illumination both with regard to the needs of the road workers and to avoid the glare of drivers

    − recommendations regarding specular reflection on wet road surfaces.

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  • 34.
    Ihs, Anita
    et al.
    Swedish National Road and Transport Research Institute.
    Velin, Hans
    Swedish National Road and Transport Research Institute.
    Vägytans inverkan på fordonshastigheter: data från 1992-19992002Report (Other (popular science, discussion, etc.))
    Abstract [sv]

    På uppdrag av Vägverket har sambandet mellan fordonshastigheter och spårdjup

    samt ojämnheter (IRI, mm/m) undersökts. Syftet har varit att ta fram underlag

    för

    revidering av transportkostnadsmodellen i Vägverkets beslutstödssystem för

    underhåll av belagda vägar (PMS).

    Hastighetsdata från Vägverkets samtliga mätpunkter för uppföljning av

    trafikarbetets förändring samt data om vägytans ojämnhet från Laser-RST

    mätningar har använts i en multipel linjär regressionsmodell. Analysen

    baseras på

    data från 1992-1999.

    Analyser utfördes för tre fordonstyper; personbil, lastbil samt lastbil med

    släp,

    dels för hela mätdygnet och dels för den ljusa delen av dygnet kl.

    9.00-15.00.

    Dessutom studerades inverkan av nederbörd på fordonshastigheten genom att

    datamaterialet indelades i tre nederbördsklasser.

    Flertalet av Vägverkets mätpunkter ligger på vägar med spårdjup mindre än

    15 mm och IRI mindre än 2,5 mm/m. De erhållna resultaten kan därför inte

    antas

    gälla för mycket ojämna och spåriga vägar.

    För personbilar var inverkan av spårdjup mycket liten. Ett ökat spårdjup med

    10 mm gav en hastighetssänkning på mindre än 1 km/h. Inte heller stora

    nederbördsmängder,

    >10 mm/dygn, innebar någon nämnvärd hastighetssänkning vid

    ökat spårdjup. En ökning av IRI med en enhet gav en hastighetssänkning på ca

    2 km/h och vid stora nederbördsmängder en hastighetssänkning med ytterligare

    0.5 km/h.

    Inte heller för lastbilar erhölls någon större hastighetssänkning med ökat

    spårdjup. Hastighetssänkningen var även i detta fall ca 1 km/h då spårdjupet

    ökade med 10 mm. Stora nederbördsmängder gav ingen ytterligare

    hastighetssänkning.

    En ökning av IRI med en enhet gav en hastighetssänkning på ca 2 km/h

    och vid stora nederbördsmängder en ytterligare sänkning med ca 0.5 km/h.

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  • 35.
    Ihs, Anita
    et al.
    Swedish National Road and Transport Research Institute.
    Velin, Hans
    Swedish National Road and Transport Research Institute.
    Wiklund, Mats
    Swedish National Road and Transport Research Institute.
    Vägytans inverkan på trafiksäkerheten: data från 1992-19982002Report (Other (popular science, discussion, etc.))
    Abstract [sv]

    The main objective of this study has been to provide the Swedish National

    Road Administration's (SNRA) pavement management system (PMS) with new models

    describing the relation between traffic safety and road surface condition. In

    the accident cost model used today, the only road surface parameter is rut

    depth and only ruts deeper than 10 mm are considered to have any influence on

    traffic safety. The relation is then linear and accident cost increases with

    increasing rut depth. The investigation carried out is based on data from the

    road surface measurements made by SNRA on state roads between 1992 and 1998

    and accidents reported by the police during the same period. Precipitation

    data has also been used. Regression analyses have mainly been used. The

    dependent Y-variable was accident ratio (accidents/100 million axle pair

    kilometres). Independent X-variables were rut depth (mm) and/or unevenness

    expressed as International Roughness Index (IRI in mm/m). The material has

    been divided into several different classes, such as traffic flow and

    precipitation classes. Using linear regression with rut depth as the only

    independent variable, it was found that the accident ratio is independent of

    rut depth. Divided into summer and winter periods, there is a tendency that

    the accident ratio decreases during summer and increases during winter with

    increasing rut depth. With linear regression with IRI as the only independent

    variable, it is found that the accident ratio increases with increasing

    unevenness for most divisions of data. This also applies when only accidents

    with personal injuries and fatal accidents are studied. By multiple linear

    regression with rut depth and IRI as independent variables, it was found that

    the accident ratio decreases with increasing rut depth and increases with

    increasing unevenness for most divisions of the material. Even though the

    data from the whole state road network is included in the analyses, 95% of

    the material represents roads with a rut depth less than 15.4 mm and an IRI

    value less than 5.1 m/m. The consequence is that the estimated linear

    relations are valid only for roads of such a good standard. A variance

    analysis that has been carried out does not, however, support the theory that

    the accident risk on the roads with the deepest ruts should differ

    dramatically from that on the roads with shallower ruts. The analysis does,

    though, show that the higher the IRI value the higher the accident risk.

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  • 36.
    Ihs, Anita
    et al.
    Swedish National Road and Transport Research Institute.
    Öberg, Gudrun
    Swedish National Road and Transport Research Institute.
    Wågberg, Lars-Göran
    Swedish National Road and Transport Research Institute.
    Trafikanters krav på vägars tillstånd: en litteraturstudie rörande trafikantenkäter och trafikintervjuer2007Report (Other academic)
    Abstract [sv]

    Today the Swedish Road Administration (SRA) regularly follows up the condition of the state roads by means of road surface measurements. It is mainly rut depth (mm) and roughness expressed in the measure International Roughness Index (IRI, mm/m) that is the bases for assessment of the road surface condition. Based on these measurements it can generally be said that the condition of the roads neither have considerably improved nor become considerably worse over the years. The trend however looks a bit different in the different SRA Regions. At the same time it is also yearly investigated how content or discontent the road users are with the maintenance of the state roads. The road users are asked about their opinion on the operation and maintenance of the roads in general as well as more specifically about their opinion concerning rutting and unevenness, i.e. the factors that are followed up by measurements. The general tendency, except for the last year, is the percentage of satisfied road users is decreasing. The percentage of satisfied road users is also low. This applies not least that the professional drivers. The agreement between the objective measurements of the condition of roads (or rather the condition measures that are used) that are done and the opinions given by the road users is not very good. There is reason to go deeper into this question and examine what requirements and expectations the road users have on the roads/road surface condition and also what measures are needed to describe the condition in a satisfactory way.

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  • 37.
    Loukopoulos, Peter
    et al.
    Swedish National Road and Transport Research Institute.
    Forsberg, Inger
    Swedish National Road and Transport Research Institute.
    Ihs, Anita
    Swedish National Road and Transport Research Institute.
    Sjögren, Leif
    Swedish National Road and Transport Research Institute.
    Trafikanternas krav på vägars tillstånd: en fokusgruppsstudie2008Report (Other academic)
    Abstract [en]

    Part of the project "Trafikanters krav på vägars tillstånd" (Motorists' requirements on the condition of road surfaces) consists of a focus group study, in which the aim is to investigate motorists' expectations regarding road-surface conditions and the factors influencing these expectations. The roads examined in this study are those belonging to the state's road network, primarily outside urban areas. Another aim is to see which names and terms motorists use to describe various road-surface problems. The results will be used to aid the design of a questionnaire as part of a later phase of the project. Six focus groups were conducted and, in total, 42 people participated - 15 private motorists (10 males and 5 females) and 27 professional motorists (15 bus drivers and 12 lorry drivers, all male). Two focus groups consisted of private motorists, one group with younger participants and another with older participants, two groups consisted of bus drivers, and two groups of lorry drivers. All participants had experienced a variety of road and driving stretches (e.g., motorways, urban driving, and long-distance driving).

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  • 38.
    Lundberg, Thomas
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Carlson, Annelie
    Linköpings universitet.
    Eriksson, Olle
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Genell, Anders
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Ihs, Anita
    Swedish National Road and Transport Research Institute, Infrastructure.
    Janhäll, Sara
    RISE.
    Sjögren, Leif
    Swedish National Road and Transport Research Institute, Infrastructure.
    Wennström, Jonas
    Indikatorer för Trafikverkets uppföljning av underhåll på belagda vägar: leveranskvaliteter för de transportpolitiska målen2022Report (Other academic)
    Abstract [en]

    One way for the Swedish Transport Administration (STA) to follow up the effects of maintenance on state roads is by using indicators. The indicators described in this report are defined as second-order indicators and are built up using underlying data. The indicators describe, in a comprehensive and transparent way, how the STA meets delivery quality parameters for punctuality, capacity, robustness, usability, safety, and environment and health. 

    In this feasibility study, a knowledge overview of the selected indicators is presented. Suggestions are also given on how the indicators can be implemented in the STA's pavement management system. The indicators studied were Safety, Comfort, Structural Condition, Rolling Resistance, Noise, Air Quality, Goods Damage, Surface Damage, Vehicle Wear, and Health Risk. Many aspects must be considered when introducing an indicator. Along with validation, it is extremely important that the indicator will be accepted and used. There are many ways to use an indicator, however, it is not ideal to only consider absolute values for a composite indicator. Relative differences in annual follow-ups are preferable to determine whether strategies have the intended effect.

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  • 39.
    Lundberg, Thomas
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Sjögren, Leif
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Gustafsson, Mika
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Ihs, Anita
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Vägytans makrotextur och dess variation: vägytemätning med mätbil2011Report (Other academic)
    Abstract [en]

    Early fault detection, particularly at construction stage, can result in substantial savings for the Swedish Transport Administration. A contributing element to these savings is to have a homogeneous bituminous surface structure. For example, load changes, at low temperatures, can create a heterogeneous surface structure that gives rise to premature maintenance needs. Established methods or macro texture measurement models are not currently available in Sweden. Other countries have made advances in this field but they have not yet had an impact in Sweden.

    An objective of this project is to maximize the possible use of existing measurement technology, quality and techniques associated with road surface measurement carried out by survey vehicles. In some cases, after a new surface has been laid, ‘object measurement’ is carried out by a survey vehicle. These measurements can be used to approve the surfacing contractor's performance in terms of longitudinal and transverse smoothness. A similar method, with specified values for homogeneous surface structures, will be developed in this project. An object is designed to provide a safe road surface throughout its design life expectancy. In order to be able to achieve this, it is important to discover surface shortcomings such as material separation. Four different models were tested in the project - all of which show promising results. Generally, all the models were able to identify the worst test surface. However, the actual "failed" road surface length of the object varied between models. This, above all, is a question of calibrating the models' limits. However, there is also potential to improve the model itself.

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  • 40.
    Nilsson, Jan-Eric
    et al.
    Swedish National Road and Transport Research Institute.
    Ihs, Anita
    Swedish National Road and Transport Research Institute.
    Sjögren, Leif
    Swedish National Road and Transport Research Institute.
    Wiman, Leif G
    Swedish National Road and Transport Research Institute.
    Wågberg, Lars-Göran
    Swedish National Road and Transport Research Institute.
    Funktionsupphandling: sammanfattning av kunskapsläge och rekommendationer för fortsatt forskning2006Report (Other academic)
    Abstract [sv]

    The Swedish concept "procurement of function" corresponds to performance contracting in Anglo-Saxon countries. The substance is that principal and agent signs a contract over the construction and maintenance of a specific project based on the services provided to future users, i.e. based on performance of the asset. This is in contrast with contracting base on technical qualities of the new road. VTI has reserved funds to provide an overview of current knowledge in this context. Four separate contributions, together with a short summary, are included in this report. One conclusion is that the experiences of this contractual form are much larger in other countries than in Sweden. We therefore have a lot to learn, not least from our closest neighbours Finland and Norway. International experiences indicate a large and growing interest in this form of contracting and provides reason for further development. A second conclusion is that Sweden in general and VTI in particular has important information of direct relevance for the development of efficient performance contracts. This knowledge must, however, typically be structured and organised along other lines than when the original research was undertaken. The institute should therefore seek to adapt the collection of information of relevance for performance contracts so that it fits in to this new framework. This includes issues such as the measurement of road surface quality and assessment of the additional costs for providing better surface quality on the one hand and the user benefits of improved quality on the other.

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  • 41.
    Nygårdhs, Sara
    et al.
    Swedish National Road and Transport Research Institute.
    Ihs, Anita
    Swedish National Road and Transport Research Institute.
    Speglande reflexion i våta vägbeläggningar: störande ljus vid vägarbeten om natten: förstudie2006Report (Other academic)
    Abstract [sv]

    With respect to traffic, roadworks are to an ever increasing extent performed during the dark hours. In these cases, lighting is a critical factor to consider. It is important that the road-user experiences good visual guidance past the road work area and that he or she is not bothered by glare from road work lighting, reflections in the roadway and other things. The safety and road work lighting should at the same time be good for the roadworker. This report reports on a pre-study of the joint Nordic project Störande ljus vid vägarbeten om natten (Disturbing lights during roadworks at night). The purpose of the project is to improve the safety both for road-users passing a roadwork area in the dark and for the persons working at the roadwork area. This particularly applies to night-time roadworks on major roads. In the main project, the disturbance that the different elements - flashing lights, vehicle lighting, electric fittings, reflections, etc. - cause the driver passing the roadwork area will be investigated, both separately and combined with each other. The project should lead to proposals for improvement and co-ordination of current regulations in the Nordic countries. Reflections in the roadway, especially when the roads are wet, can be experienced as problematic for the road-users. If the road surface is damp, glare occurs, for example from oncoming vehicle headlights or from flashing lights and signs by the road work area. In this pre-study, an investigation of the specular reflection in some typical Nordic road surfaces has been made, aimed to form the basis for planning the main study. The purpose with the pre-study has principally been to survey what values of specular reflection, retroreflection and luminance coefficient are common for road surfaces in the Scandinavian countries Denmark, Norway and Sweden. Finland, which originally should also have been part of the study, has been excluded due to resource and time limits, for the present. Measurement of the specular reflection has been made on dry and wet road surfaces with a modified retroreflectometer (of the type LTL-X). It has been supplemented with a vertical mirror directing the observation direction towards the lighting direction in such a way as to correspond to a motorist observing a point on the road surface 30 metres in front of the vehicle, which is lightened by a headlight 30 metres further away. Since the instrument was relatively untested, the aim of this pre-study was also to acquire experience and routines for measuring specular reflection.

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  • 42.
    Persson, Kerstin
    et al.
    Swedish National Road and Transport Research Institute.
    Ihs, Anita
    Swedish National Road and Transport Research Institute.
    Kalciumklorid i vinterväghållningen: litteraturstudie1998Report (Other academic)
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  • 43.
    Sjögren, Leif
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Ihs, Anita
    Swedish National Road and Transport Research Institute, Infrastructure.
    Edvardsson, Karin
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Wennström, Jonas
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Haider, Manfred
    AIT.
    Casse, Christophe
    BRRC.
    Van Geem, Carl
    BRRC.
    Benbow, Emma
    TRL.
    Wright, Alex
    TRL.
    Žnidarič, Aleš
    ZAG.
    Kokot, Darko
    ZAG.
    Kreslin, Maja
    ZAG.
    Overall road asset performance2013Report (Other academic)
    Abstract [en]

    The HeRoad project has investigated the road asset management situation and what practises exist to collect performance measurements in Europe. This has been done in a view from the operational level using a holistic perspective, in the sense that multiple assets and the cross relation between those are included. HeRoad’s approach by addressing the need for condition performance measurements can be justified with some words from (AASHTO, 2011); “What´s measured gets done; if you do not measure results, you cannot tell success from failure.” This implies that the view of investigation has been from the operational level more than from the strategic level (bottom–up).

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