Publications
Change search
Refine search result
1234567 1 - 50 of 855
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the 'Create feeds' function.
  • 1. Agustsson, Larus
    Danish experiences with speed zones/variable speed limits2001In: Proceedings of the conference Traffic Safety on Three Continents: International conference in Moscow, Russia, 19-21 September, 2001 / [ed] Asp, Kenneth, Linköping: Statens väg- och transportforskningsinstitut, 2001, Vol. 18A:3, p. 12-Conference paper (Other academic)
    Abstract [en]

    The first Danish Road Safety Action plan in 1989 reduced the number of fatalities and casualties by 30% by the year 2000. The goal of the new Danish Road Safety Action Plan is to reduce the number of fatalities and serious casualties by 40% from 1998 to the year 2012. One of the actions that will be used to actuate this plan is the implementation of speed management and speed zones. This paper discusses the Danish experience with speed zones and variable speed limits

  • 2.
    Ahmed, Abubeker
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Hellman, Fredrik
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Erlingsson, Sigurdur
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Full scale accelerated pavement tests to evaluate the performance of permeable and skeletal soil block pavement systems2016In: The Roles of Accelerated Pavement Testing in Pavement Sustainability: Engineering, Environment, and Economics, Springer International Publishing , 2016, p. 131-144Chapter in book (Other academic)
    Abstract [en]

    The increasing proportion of paved surface due to urbanization means that the conditions for urban trees and vegetation to survive have deteriorated. Factors such as air pollution, poor drainage, and the lack of usable soil for root growth contribute to the short life expectancy of urban trees. To meet this challenge, several permeable and "structural" or "skeletal soils" have been developed as alternatives to the typical compacted soil required to bear the weight of vehicular traffic in urban areas. The main objective of this study is to evaluate the resistance to permanent deformation of permeable and skeletal soil pavement structures based on full scale accelerated pavement tests (APT) using a heavy vehicle simulator (HVS). Interlocking paving stones of various types were used as permeable surface layer for the test structures. The results demonstrated that the permeable test structures exhibited higher permanent deformation than the corresponding impervious structures. The skeletal soil with bituminous base layer, however, produced performance comparable to the impervious reference test structures.

  • 3.
    Ahmed, Abubeker W.
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology. KTH.
    Mechanistic-Empirical Modelling of Flexible Pavement Performance: Verifications Using APT Measurements2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Mechanistic-Empirical  (M-E)  pavement  design  procedures  are  composed  of  a  reliable  response model to estimate the state of stress in the pavement and distress models in order to predict the different types of pavement distresses due to the prevailing traffic and environmental conditions. One of the main objectives of this study was to develop a response model based on multilayer elastic  theory   (MLET)  with  improved  computational  performance  by   optimizing  the   time consuming parts of the MLET processes. A comprehensive comparison of the developed program with  two  widely  used  programs  demonstrated  excellent  agreement  and  improved  computational performance.  Moreover,  the  program  was  extended  to  incorporate  the  viscoelastic  behaviour  of bituminous materials through elastic-viscoelastic correspondence principle. A procedure based on collocation of linear viscoelastic (LVE) solutions at selected key time durations was also proposed that improved the computational performance for LVE analysis of stationary and moving loads. A comparison  of  the  LVE  responses  with  measurements  from  accelerated  pavement  testing  (APT) revealed a good agreement. Furthermore the developed response model was employed to evaluate permanent deformation models  for  bound  and  unbound  granular  materials  (UGMs)  using  full  scale  APTs.  The  M-E Pavement  Design  Guide  (MEPDG)  model  for  UGMs  and  two  relatively  new  models  were evaluated  to  model  the  permanent  deformation  in  UGMs.  Moreover,  for  bound  materials,  the simplified  form  of  the  MEPDG  model  for  bituminous  bound  layers  was  also  evaluated.  The measured  and  predicted  permanent  deformations  were  in  general  in  good  agreement,  with  only small discrepancies between the models. Finally, as heavy traffic loading is one of the main factors affecting the performance of flexible pavement, three types of characterizations for heavy traffic axle load spectrum for M-E analysis and design of pavement structures were evaluated. The study recommended an improved approach that enhanced the accuracy and computational performance.

    List of papers
    1. Evaluation of permanent deformation models for unbound granular materials using accelerated pavement tests
    Open this publication in new window or tab >>Evaluation of permanent deformation models for unbound granular materials using accelerated pavement tests
    2013 (English)In: International Journal on Road Materials and Pavement Design, ISSN 1468-0629, E-ISSN 2164-7402, Vol. 14, no 1, p. 178-195Article in journal (Refereed) Published
    Abstract [en]

    Mechanistic-empirical (M-E) pavement design methods have become the focus of modern pavement design procedure. One of the main distresses that M-E design methods attempt to control is permanent deformation (rutting). The objective of this paper is to evaluate three M-E permanent deformation models for unbound granular materials, one from the US M-E pavement design guide and two other relatively new models. Two series of heavy vehicle simulator (HVS) tests with three different types of base material were used for this purpose. The permanent deformation, wheel loading, pavement temperature, and other material properties were continuously controlled during the HVS tests. Asphalt concrete layers were considered as linear elastic where stress-dependent behaviour of unbound materials was considered when computing responses for the M-E permanent deformation models with a nonlinear elastic response model. Traffic wandering was also accounted for in modelling the traffic by assuming it was normally distributed and a time-hardening approach was applied to add together the permanent deformation contributions from different stress levels. The measured and predicted permanent deformations are in general in good agreement with only small discrepancies between the models. Model parameters were also estimated for three different types of material.

    Place, publisher, year, edition, pages
    Taylor & Francis Group, 2013
    Keyword
    Rutting (wheel), Unbound base, Granular, Stress (in material)
    National Category
    Infrastructure Engineering
    Research subject
    Road: Highway design, Road: Pavement design; Road: Materials, Road: Aggregate and stone materials
    Identifiers
    urn:nbn:se:vti:diva-6941 (URN)10.1080/14680629.2012.755936 (DOI)
    Available from: 2014-07-17 Created: 2014-07-17 Last updated: 2017-12-05Bibliographically approved
    2. Modeling of flexible pavement structure behavior: Comparisons with Heavy Vehicle Simulator measurements
    Open this publication in new window or tab >>Modeling of flexible pavement structure behavior: Comparisons with Heavy Vehicle Simulator measurements
    2012 (English)In: Advances in Pavement Design Through Full-Scale Accelerated Pavement Testing / [ed] Jones, Harvey, Mateos & Al-Qadi, London: Taylor & Francis Group, 2012, p. 493-503Conference paper, Published paper (Refereed)
    Abstract [en]

     A response model to be employed in a mechanistic-empirical pavement performance predictionmodel based on multilayer elastic theory has been developed. An iterative approach using a method of successiveover-relaxation of a stress dependency model is used to account for the nonlinear behavior of unbound materials. Asphalt and subgrade materials are assumed to be linear elastic. The response model was verified against two series of Heavy Vehicle Simulator (HVS) response measurements made under a variety of wheel loadconfigurations and at different pavement temperatures. A comparison with Falling Weight Deflectometer (FWD)data was also carried out. The model was subsequently used to predict permanent deformation from the HVS testing using simple work hardening models. A time hardening approach has been adopted to combine permanentdeformation contributions from stress levels of different magnitude.The response model outputs and the predictedpermanent deformations were generally in good agreement with the measurements.

    Place, publisher, year, edition, pages
    London: Taylor & Francis Group, 2012
    Keyword
    Pavement, Simulation, Deflectograph, Model
    National Category
    Civil Engineering
    Research subject
    Road: Highway design, Road: Pavement design
    Identifiers
    urn:nbn:se:vti:diva-6942 (URN)10.1201/b13000-61 (DOI)ISBN 978-0-415-62138-0 (ISBN)
    Conference
    The 4th International Conference on Accelerated Pavement Testing
    Available from: 2014-07-17 Created: 2014-07-17 Last updated: 2014-08-22Bibliographically approved
    3. Fast layered elastic response program for the analysis of flexible pavement structures
    Open this publication in new window or tab >>Fast layered elastic response program for the analysis of flexible pavement structures
    2013 (English)In: International Journal on Road Materials and Pavement Design, ISSN 1468-0629, E-ISSN 2164-7402, Vol. 14, no 1, p. 196-210Article in journal (Refereed) Published
    Abstract [en]

    One of the key components in analysing pavement structural behaviour is the response model which is used to estimate the stresses, strains and displacements of the pavement structure subjected to the existing traffic, taking into account the material properties and prevailing environmental conditions. Multilayer elastic theory (MLET) is often preferred over other methods such as the finite element method, due to its computational performance for repeated applications. A new elastic response analysis program has been developed based on the Burmister MLET theory to calculate the response of flexible pavement structures. In the development of the program, the time-consuming part of MLET processes was optimised. To improve the convergence and accuracy of responses in the vicinity of the surface of the top layer, an approach based on Richardson's extrapolation was employed. Moreover, an iterative approach to model stress dependency of unbound granular materials was incorporated. A comprehensive comparison of the program with two frequently used programs demonstrated an excellent agreement and improved performance.

    Place, publisher, year, edition, pages
    Taylor & Francis Group, 2013
    Keyword
    Elasticity, Flexible pavement, Model (not math)
    National Category
    Civil Engineering
    Research subject
    Road: Highway design, Road: Surfacing
    Identifiers
    urn:nbn:se:vti:diva-6944 (URN)10.1080/14680629.2012.757558 (DOI)
    Available from: 2014-07-17 Created: 2014-07-17 Last updated: 2017-12-05Bibliographically approved
    4. Characterization of heavy traffic axle load spectra for mechanistic-empirical pavement design applications
    Open this publication in new window or tab >>Characterization of heavy traffic axle load spectra for mechanistic-empirical pavement design applications
    2015 (English)In: The international journal of pavement engineering, ISSN 1029-8436, E-ISSN 1477-268X, Vol. 16, no 6, p. 488-501Article in journal (Refereed) Published
    Abstract [en]

     Heavy traffic axle load spectrum (ALS) is  one of the key inputs for mechanistic-empirical analysis and design of pavement structures. Frequently, the entire ALS is aggregated into Equivalent Number of Single Axle Loads (ESAL) or assumed to have Constant Contact  Area  (CCA)  or  Constant  Contact  Pressure  (CCP).  These characterizations affect the accuracy and computational performance of the pavement analysis. The objective of this study was to evaluate these  characterizations  based  on  predicted  performances  to  rutting and fatigue cracking of several pavement structures subjected to ALS data collected from 12 Bridge-Weigh-In-Motion stations. The results indicated  that  for  layers  below  the  top  25  cm,  all  characterizations produced similar values of predicted rutting. However, for the top 25 cm, the methods differed in the predicted performances to rutting and fatigue cracking. Furthermore an improvement to the CCA approach was proposed that enhanced the accuracy while maintaining the same level of computational performance.

    Place, publisher, year, edition, pages
    Taylor & Francis Group, 2015
    Keyword
    Axle load, Heavy vehicle, Pavement design, Rutting, Cracking, Prediction, Accuracy
    National Category
    Infrastructure Engineering
    Research subject
    30 Road: Highway design, 32 Road: Pavement design
    Identifiers
    urn:nbn:se:vti:diva-6945 (URN)10.1080/10298436.2014.943131 (DOI)000354458200003 ()2-s2.0-84929283717 (Scopus ID)
    Available from: 2014-07-17 Created: 2014-07-17 Last updated: 2017-12-05Bibliographically approved
    5. Viscoelastic modelling of pavement structure behaviour in a full scale accelerated pavement test
    Open this publication in new window or tab >>Viscoelastic modelling of pavement structure behaviour in a full scale accelerated pavement test
    (English)Manuscript (preprint) (Other academic)
    Keyword
    Viscoelasticity, Full scale, Flexible pavement, Test, Performance, Deformation, Model (not math), Rutting (wheel)
    National Category
    Civil Engineering
    Research subject
    30 Road: Highway design, 32 Road: Pavement design
    Identifiers
    urn:nbn:se:vti:diva-6947 (URN)
    Available from: 2014-07-17 Created: 2014-07-17 Last updated: 2016-01-11Bibliographically approved
    6. Evaluation of permanent deformation model for asphalt concrete mixtures by means of extra-large wheel tracking and full scale accelerated pavement tests
    Open this publication in new window or tab >>Evaluation of permanent deformation model for asphalt concrete mixtures by means of extra-large wheel tracking and full scale accelerated pavement tests
    (English)Manuscript (preprint) (Other academic)
    Keyword
    Rutting, Deformation, Bituminous mixture, Flexible pavement, Mathematical model, Full scale, Test
    National Category
    Civil Engineering
    Research subject
    30 Road: Highway design, 32 Road: Pavement design
    Identifiers
    urn:nbn:se:vti:diva-6949 (URN)
    Available from: 2014-07-17 Created: 2014-07-17 Last updated: 2016-01-25Bibliographically approved
  • 4.
    Ahmed, Abubeker W.
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Biligiri, Krishna Prapoorna
    Department of Civil Engineering Indian Institute of Technology Kharagpur .
    Hakim, Hassan
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    An Algorithm to Estimate Rational Values of Phase Angles and Moduli of Asphalt Mixtures2013In: International Journal of Pavement Research and Technology (IJPRT), ISSN ISSN 1997-1400, Vol. 6, no 6, p. 745-754Article in journal (Refereed)
    Abstract [en]

    The objective of this study was to develop and evaluate an algorithm based on Fast Fourier Transform (FFT) that can calculate rational values of phase angle (f) and moduli of the variants of asphalt mixtures for the data obtained from the different frequency sweep tests. f and moduli for ten different asphalt mixtures resulting in over 690 data points collected from both USA and Sweden were computed using FFT. Theoretical observations revealed that there were significant differences for f between FFT and other methods to the order of 10-50%; however, there was no difference in moduli estimates for any mix and was independent of the test. Precisely, the FFT method produced rational f for mixtures that deviate from conventional mixture properties. Furthermore, statistical comparisons corroborated the predicted f estimates indicative of significant differences between the analysis techniques; but, the moduli were unaffected by the analysis methods. The study successfully illustrated the FFT technique, a user-friendly analytical procedure that can obviate the errors in the rational estimation of the acutely sensitive viscoelastic parameters.

  • 5.
    Ahmed, Abubeker W.
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Erlingsson, Sigurdur
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Characterization of heavy traffic axle load spectra for mechanistic-empirical pavement design applications2015In: The international journal of pavement engineering, ISSN 1029-8436, E-ISSN 1477-268X, Vol. 16, no 6, p. 488-501Article in journal (Refereed)
    Abstract [en]

     Heavy traffic axle load spectrum (ALS) is  one of the key inputs for mechanistic-empirical analysis and design of pavement structures. Frequently, the entire ALS is aggregated into Equivalent Number of Single Axle Loads (ESAL) or assumed to have Constant Contact  Area  (CCA)  or  Constant  Contact  Pressure  (CCP).  These characterizations affect the accuracy and computational performance of the pavement analysis. The objective of this study was to evaluate these  characterizations  based  on  predicted  performances  to  rutting and fatigue cracking of several pavement structures subjected to ALS data collected from 12 Bridge-Weigh-In-Motion stations. The results indicated  that  for  layers  below  the  top  25  cm,  all  characterizations produced similar values of predicted rutting. However, for the top 25 cm, the methods differed in the predicted performances to rutting and fatigue cracking. Furthermore an improvement to the CCA approach was proposed that enhanced the accuracy while maintaining the same level of computational performance.

  • 6.
    Ahmed, Abubeker W.
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Erlingsson, Sigurdur
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Evaluation of a permanent deformation model for asphalt concrete mixtures using extra-large wheel-tracking and heavy vehicle simulator tests2015In: International Journal on Road Materials and Pavement Design, ISSN 1468-0629, E-ISSN 2164-7402, Vol. 16, no 1, p. 154-171Article in journal (Refereed)
    Abstract [en]

    This paper evaluates a mechanistic–empirical permanent strain model for asphalt concrete mixtures. The evaluation was carried out based on two different types of tests: an extra-large wheel-tracking (ELWT) test and a full-scale accelerated pavement test using a heavy vehicle simulator (HVS). Asphalt slabs from three different types of asphalt mixtures were prepared for the ELWT test and tested at several pavement temperatures and tyre inflation pressures. Lateral wandering was also incorporated.

    The measured permanent deformations in the asphalt slabs were thereafter modelled using the permanent strain model from the US Mechanistic-Empirical Pavement Design Guide and model parameters were estimated for the three types of mixes. For validation, data from an HVS tested pavement structure consisting of the same asphalt mixtures as those tested using the ELWT were used. A set of calibration factors for the three mixtures were therefore obtained between the two tests. In all cases, the calibration factors were within ±20% from unity. Differences in geometry, scale, wheel loading configuration as well as the speed of loading between the two test devices could be the possible reasons for the differences in observed calibration factors.

  • 7.
    Ahmed, Abubeker W.
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Erlingsson, Sigurdur
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Evaluation of permanent deformation models for unbound granular materials using accelerated pavement tests2013In: International Journal on Road Materials and Pavement Design, ISSN 1468-0629, E-ISSN 2164-7402, Vol. 14, no 1, p. 178-195Article in journal (Refereed)
    Abstract [en]

    Mechanistic-empirical (M-E) pavement design methods have become the focus of modern pavement design procedure. One of the main distresses that M-E design methods attempt to control is permanent deformation (rutting). The objective of this paper is to evaluate three M-E permanent deformation models for unbound granular materials, one from the US M-E pavement design guide and two other relatively new models. Two series of heavy vehicle simulator (HVS) tests with three different types of base material were used for this purpose. The permanent deformation, wheel loading, pavement temperature, and other material properties were continuously controlled during the HVS tests. Asphalt concrete layers were considered as linear elastic where stress-dependent behaviour of unbound materials was considered when computing responses for the M-E permanent deformation models with a nonlinear elastic response model. Traffic wandering was also accounted for in modelling the traffic by assuming it was normally distributed and a time-hardening approach was applied to add together the permanent deformation contributions from different stress levels. The measured and predicted permanent deformations are in general in good agreement with only small discrepancies between the models. Model parameters were also estimated for three different types of material.

  • 8.
    Ahmed, Abubeker W
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Erlingsson, Sigurdur
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Mechanistic modelling of HVS flexible pavement structure2012In: EPAM 2012: Malmö, Sweden, 5–7 September: 4th European pavement and asset management conference, Linköping: Statens väg- och transportforskningsinstitut, 2012, , p. 13Conference paper (Other (popular science, discussion, etc.))
    Abstract [en]

    A response model to be employed in a mechanistic-empirical pavement performance prediction model based on multilayer elastic theory has been developed. An iterative approach using a method of successive over-relaxation of stress dependency model is used to account for the nonlinear behaviour of unbound materials. Asphalt and subgrade materials are assumed as linear elastic. The response model is verified using heavy vehicle simulator (HVS) response measurements made under variety of wheel load configurations and at different pavement temperatures. The permanent deformation behaviours of the HVS structure is also modelled using mechanistic empirical approach and by employing permanent deformation prediction models. A time hardening approach has been applied to combine permanent deformation contributions from stress levels of different magnitude. The response model outputs and the predicted permanent deformations are in general in good agreement with the measurements.

  • 9.
    Ahmed, Abubeker W.
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Erlingsson, Sigurdur
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Numerical validation of viscoelastic responses of a pavement structure in a full-scale accelerated pavement test2015In: The international journal of pavement engineering, ISSN 1029-8436, E-ISSN 1477-268XArticle in journal (Refereed)
    Abstract [en]

    This paper demonstrates the application of a generalised layered linear viscoelastic (LVE) analysis for estimating the structural response of flexible pavements. A comparison of the direct layered viscoelastic responses with approximate solutions based on the linear elastic (LE) and LVE collocation methods was also carried out. The different approaches were implemented by extending a layered elastic program with an improved computational performance. The LE and LVE collocation methods were further extended for analysis of pavements under moving loads.

    The methods were illustrated by analysing a pavement structure subjected to moving wheel loads of 30, 50, 60 and 80 kN using a Heavy Vehicle Simulator (HVS). The various responses (stresses and strains) in the pavement, at pavement temperatures of 0, 10 and 20°C, were measured using various types of sensors installed in the structure. It was shown that the approximated LVE solution based on the LE collocation method agreed very well with the measurements and is computationally the least expensive.

  • 10.
    Ahmed, Abubeker W
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Erlingsson, Sigurdur
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology. University of Iceland.
    Viscoelastic Response Modelling of a Pavement under Moving Load2016In: Transportation Research Procedia, 2016, Vol. 14, p. 748-757Conference paper (Refereed)
    Abstract [en]

    This paper demonstrates the application of a generalized layered linear viscoelastic (LVE) analysis for estimating flexible pavements' structural response. The procedure is based on the Multi-Layered Elastic Theory (MLET) and the elastic-viscoelastic correspondence principle using a numerical inverse Laplace transform. A comparison of the direct layered viscoelastic responses with approximate solutions based on the elastic collocation method was also carried out. Furthermore, it is proposed to use the collocation method using LVE solutions at selected time durations in order to improve the accuracy of the elastic collocation method. The LVE collocation method was further extended for analysis of moving loads. The method was illustrated by analysing a pavement structure subjected to moving wheel loads of 30, 50, 60 and 80 kN using a Heavy Vehicle Simulator (HVS). The various responses (stresses and strains) in the pavement, at different pavement temperatures, were measured using various types of sensors installed in the structure. The LVE calculations agreed very well with the measurements.

  • 11.
    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

  • 12. Alten, Karoline
    et al.
    Deix, Stefan
    Peelen, Willy
    Wessels, Jos
    Courage, Wim
    Ravnikar Turk, Mojca
    Skaric Palic, Sandra
    Acalin, Nina
    Lundkvist, Sven-Olof
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Asset service condition assessment methodology (ASCAM Project)2012In: EPAM 2012, Malmö, Sweden, 5–7 September: 4th European pavement and asset management conference, Linköping: Statens väg- och transportforskningsinstitut, 2012, , p. 12Conference paper (Other academic)
    Abstract [en]

    Allocating financial resources among different sub-assets of a country’s road infrastructure is a challenge that is highly dependent on the strategic priorities and organisational structure of the infrastructure operator. While some agencies in Europe deal with pavements, bridges, tunnels or road furniture completely independently, others find that they have one mutual budget that needs to be shared out among the different assets in a way that represents their respective need for maintenance. The criteria upon which such allocations are based may be political, empirical, or based on stakeholder/user interests. The goal of the project ASCAM – Asset Service Condition Assessment Methodology – was to develop a framework for cross-asset management that can be used to objectively assign a budget to certain assets. While previous research projects have already compiled lists of various key performance indicators, ASCAM aimed to find mutual indices such as an “end user service level” that could be used to judge all sub-assets on equal terms and thus compare their condition on the same scale.

    By looking at asset management in the ASCAM partner countries and other European road agencies, the best-practice in individual asset management was extracted to develop the framework and perform a proof-of-concept for the project. While other projects such as PROCROSS within the same ERA-NET call also worked on cross-asset management – but from a top-down approach – ASCAM’s bottom-up approach looked at the more technical aspects of evaluating infrastructure condition and making a budgetary assignment based on the current and predicted state of the assets.

  • 13.
    Alzubaidi, Hossein
    Swedish National Road and Transport Research Institute.
    Drift och underhåll av grusvägar: litteraturstudie1999Report (Other academic)
    Abstract [sv]

    Grusvägarna omfattar en väsentlig del av det svenska vägnätet. Det statliga vägnätet omfattar 98 015 km väg varav 22 136 km (22%) är grusvägar (1997). Förutom de statliga grusvägarna finns även ca 35000 km enskilda grusvägar med statsbidrag och ca 210 000 km skogsbilvägar.

    Föreliggande litteraturstudie ingår som en första del i doktorandprojektet "”Effektiva produktionsmetoder inom drift och underhåll av grusvägar”".

    Denna rapport behandlar drift och underhåll av grusvägar huvudsakligen med inriktning mot grusslitlagret under barmarksperioden. I Sverige och de nordiska länderna infaller denna period normalt mellan maj och oktober. Med begreppet ”Drift och underhåll av grusvägar” menas i denna rapport all verksamhet som berör skötsel av grusvägar så att vägen hålls i farbart skick. Litteraturstudien består av tio kapitel vars rubriker finns i följande avsnitt:

    Kapitel 1 "Inledning", kapitel 2 "Grundläggande begrepp", kapitel 3 "Allmänt om vägnätet", kapitel 4 "Nedbrytning av grusvägar", kapitel 5 "Tekniska krav på grusvägar i Sverige", kapitel 6 "Faktorer som påverkar underhållet av grusvägar", kapitel 7 "Metoder för drift och underhåll av grusvägar", kapitel 8 "Tillståndsbedömning av grusvägar", kapitel 9 "Planering och värdering av drift- och underhålls-åtgärder", kapitel 10 "Referenser", Kapitel 11 "Figur- och tabellförteckning".

  • 14.
    Alzubaidi, Hossein
    Swedish National Road and Transport Research Institute.
    Miljöeffekter av dammbindning av grusvägar1999Report (Other academic)
  • 15.
    Alzubaidi, Hossein
    Swedish National Road and Transport Research Institute.
    Operation and maintenance of gravel roads: a literature study1999Report (Other academic)
    Abstract [en]

    Gravel roads form a large percentage of the road network in Sweden. The public road network under the jurisdiction of the Swedish National Road Administration has a total length of some 98,000 kilometres. About 22,000 km of this network consists of gravel roads. In addition, there are about 74,000 kilometres of private road and 210,000 kilometres of forest roads. The report describes the present position in the operation and maintenance of gravel roads. It presents a comprehensive literature survey of current and recent national and international research. It deals only with summer maintenance and focuses primarily on roads surfaced with aggregate. The following areas are treated in the report: - Definitions and terms regarding the operation and maintenance of gravel roads.- General description of the Swedish road network. - Major factors causing deterioration of gravel roads. - Technical requirements for Swedish gravel roads. - Factors, which influence the operation and maintenance of gravel roads. - Operation and maintenance methods. - Condition assessment of gravel roads. - Planning and evaluation of operation and maintenance measures.

  • 16.
    Alzubaidi, Hossein
    Swedish National Road and Transport Research Institute.
    Tillståndsbedömning av grusvägar: en sammanfattning av: On rating of gravel roads. Doctoral thesis at the Division of Highway Engineering, Royal Institute of Technology, Stockholm2002Report (Other academic)
    Abstract [sv]

    Bakgrunden till avhandlingen är att en metod for tillståndsbedömning av grusvägar utgör en viktig del av ett styrsystem som skall leda till effektivitet i underhållsverksamheter. Vägverket tillämpar en metod för tillståndsbedömning av grusvägar, förkortad VVMB 106, vilken tar hänsyn till jämnhet, löst grus samt damm. Representativa 100 m långa slumpvalda grusvägsdelsträckor används för själva bedömningen. Delsträckans tillstånd indelas i klass 1 (god), klass 2 (godtagbar) eller klass 3 (dålig). Tillståndet bedöms tillfredsställande om delsträckan placeras i klass 1 eller klass 2 avseende jämnhet och bundenhet, annars bedöms det otillfredsställande. Syftet med avhandlingen är dels att analysera VVMB 106 för att finna dess svagheter, dels att utveckla en ny och förbättrad metod.

  • 17.
    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.

  • 18.
    Andersson, G
    et al.
    Svenska Väginstitutet.
    Lundeberg, Erik
    Svenska Väginstitutet.
    Undersökningar rörande bromslängden för bilar vid olika väglag1931Report (Other academic)
  • 19.
    Andersson, Mats
    Swedish National Road and Transport Research Institute, Society, environment and transport, Transport economics Stockholm.
    Marginal railway renewal costs: a survival data approach2007Report (Other academic)
    Abstract [en]

    In this paper, renewal costs for railway tracks are investigated using survival analysis. The purpose is to derive the effect from increased traffic volumes on rail renewal cycle lengths and to calculate associated marginal costs. A flow sample of censored data containing almost 1 500 observations on the Swedish main railway network is used. We specify Weibull accelerated failure time regression models, and estimate deterioration elasticities for total tonnage as well as for passenger and freight tonnages separately. Marginal costs are calculated as a change in present values of renewal costs from premature renewal following increased traffic volumes.

  • 20.
    Andersson, Mats
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Transport economics Borlänge.
    Smith, Andrew
    Institute for Transport Studies, University of L eeds.
    Wikberg, Åsa
    Swedish National Road and Transport Research Institute, Society, environment and transport, Transport economics Borlänge.
    Wheat, Phillip
    Institute for Transport Studies, University of L eeds.
    The marginal cost of railway track renewals: a sample selection modelling approach2010Report (Other academic)
    Abstract [en]

    Economic theory advocates marginal cost pricing for efficient utilisation of transport infrastructure. A growing body of literature has emerged on the issue of marginal infrastructure wear and tear costs, but the majority of the work is focused on costs for infrastructure maintenance. Railway track renewals are a substantial part of an infrastructure manager’s budget, but in disaggregated statistical analyses, they cause problems for traditional regression models since there is a piling up of values of the dependent variable at zero. Previous econometric work has sought to circumvent the problem by aggregation in some way. In this paper we work with disaggregate (track-section) data, including the zero observations, but apply censored and sample selection regression models to overcome the bias that would result from estimation using OLS. We derive track renewal cost elasticities with respect to traffic volumes and in turn marginal renewal costs using Swedish railway renewal data over the period 1999 to 2009. Our paper is the first paper in the literature that we are aware of to report usage elasticities specifically for renewal costs and therefore adds important new evidence to the previous literature where there is a paucity of studies on renewals and considerable uncertainty over the effects of rail traffic on renewal costs. In the Swedish context, we find that the inclusion of marginal track renewal costs in the track access pricing regime, which currently only reflects marginal maintenance costs, would add substantially to the existing track access charge.

  • 21.
    Andren, Peter
    et al.
    Swedish National Road and Transport Research Institute.
    Sjögren, Leif
    Swedish National Road and Transport Research Institute.
    An explanation to the VTI FILTER documents2001Report (Other academic)
  • 22.
    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.

  • 23.
    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.

  • 24.
    Anund, Anna
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Räfflor: effekter och konsekvenser av olika räffeltyper vid mitträffling på 2-fältsvägar2014Report (Other academic)
    Abstract [en]

    Milled rumble strips is one way to attract the drivers’ attention when they involuntarily are about to leave the lane. The rumble strips provide both internal and external noise but also vibrations in the vehicle. The overall aim of this work is to elucidate the effects and consequences of the use of intermittent milled rumble strips compared to sinus milled rumble strips in the center of the road. The comparison take into account; external noise, internal noise, vibrations, damage to the road surface and the price. However, due to lack of data, vibrations and price issues are excluded here. The results show that the intermittent rumble strips provide an increase of external noise on the 2–8 dB (A). The corresponding figure for the sinus rumble strip is 0.0 to 4 dB (A). Further, it is found that the sinus rumble strips provide more low frequency noise (30–40Hz) compare to the intermittent rumble strips (60–160 Hz). Maximum noise from intermittent rumble strips are obtained around 80–90 km/h, and at 90 km/h the threshold for noise for those living close to the road is 90–140 meters. It is not known at what speed the sinus rumble strip provide the maximum noise. Regarding the internal noise most studies have focused on passenger cars and an increase in internal noise when driving on intermittent rumble strips varies between 13–17 dB (A). Results from simulator studies show that even low levels of internal noise is helpful for drivers who are about to leave the lane due to sleepiness. The sinus rumble strips provide not only noise but also vibrations.

  • 25.
    Anund, Anna
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Ahlström, Christer
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Forsberg, Inger
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes.
    Nyberg, Jonna
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes.
    Räfflor i mitten av körfältet: ett försök i Skaulo2010Report (Other academic)
    Abstract [en]

    The aim with the study was to evaluate the effects on road user behavior when using milled rumble strips in the centre of the lane on a road 6.5 meters wide. The evaluation included measurements of speed and lateral position. Measurements were done before and after milling, and focus group interviews were perfomed with motorcyclists and truck drivers after realisation. The results of the measurements of speed and lateral position showed that milled rumble strips in the middle of the lane do not affect car drivers. A slight increase in the standard deviation of the lateral position for passenger cars may be noted. Truck drivers were affected slightly more: significantly lower speed was detected as well as that trucks moved closer to the road centre, and the standard deviation of lateral position increased. This is not what the drivers themselves report to experience. They say that their choice of speed is unchanged. All in all truck drivers were negative to the rumble strips in the centre of the lane. One argument was that they disturbe the "line" during the drive and make it difficult to choose the placement they want to have. Truck drivers do not believe that they, in case of falling asleep, (in contrary to expectations) would have time enough to act in order to aviod a crash, since the roads are too narrow. Also the motorcyclists are negative to the centre lane location of rumble strips. They agree, however, that rumble strips in the centre of the road and in the roadside are postitive in terms of traffic safety.

  • 26.
    Anund, Anna
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Dukic, Tania
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Chalkia, Eleni
    CERTH/HIT.
    Project presentation2009Report (Other academic)
    Abstract [en]

    SAFEWAY2SCHOOL is a European research project carried out by research institutes, universities and industry in order to enhance safety for children on their daily way to school. SAFEWAY2SCHOOL aims to design, develop, integrate and evaluate technologies for providing a holistic and safe transportation service for children, from their home door to the school door and vice versa, encompassing tools, services and training for all key actors in the relevant transportation chain. These include optimal route planning and rerouting for school buses to maximize safety, on-board safety applications (i.e. for speed control and seat belts), "intelligent" bus stops, effective warning and information systems for bus drivers, children, parents and the surrounding traffic; as well as training schemes for all actors. The project innovative systems, services and training schemes will be tested in 4 sites Europewide, including North (Sweden), Central (Austria), South (Italy) and Eastern (Poland) Europe; to evaluate their usability, efficiency, user acceptance and market viability; taking into account the very different children's transportation to/from school systems across the different European regions as well as key cultural and socio-economic aspects.

  • 27.
    Anund, Anna
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Fors, Carina
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Eriksson, Jennie
    Occas AB.
    Utvärderingsmodell för ITS-baserade system vid hållplats: kunskapsöversikt och förslag på forskningsbehov2015Report (Other academic)
    Abstract [sv]

    Det finns nya produkter av typen varningssystem som syftar till att öka säkerhet och trygghet för oskyddade trafikanter. De har ofta tagits fram med särskilt fokus på barn. Produktutvecklarna har utvärderat sina produkter med positiva resultat och intresset hos Trafikverket och kommuner är stort för flera av dessa produkter. En typ av system är utmärkning vid hållplatser där blinkande ljus aktiveras när det finns oskyddade trafikanter i närheten, ett så kallat ITS-baserat varningssystem. Det finns idag ett antal platser i landet där sådana anläggningar är i bruk som ”försök” och det har skett utvärderingar av valda system vid hållplats som visat att systemen sannolikt är effektiva när det gäller att reducera hastigheten hos förbipasserande. Det finns dock en avsaknad av ett samlat utvärderingsupplägg. Avsaknaden av systematisk utvärdering har bidragit till bristen på formella beslut för att integrera denna typ av produkt i Vägar och Gators Utformning, VGU eller i Trafiklagstiftningen. I Trafikverkets region Stockholm har man utifrån resenärernas behov och i samarbete med kommunerna kring glesbygdsproblematik, särskilt intresse i att dessa produkter blir möjliga att använda. En förutsättning för detta är en systematisk utvärdering med avseende på om ett specifikt system fyller den funktion som det var avsett att fylla.

  • 28.
    Anund, Anna
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Forsberg, Inger
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes.
    Boende, pendlare och lastbilsförare tycker till om riksväg 23 och riksväg 402012Report (Other academic)
    Abstract [en]

    It is obvious that those who live near a road like to be involved during the planning phase of a road reconstruction. The Swedish Transport Administration would most likely benefit from making residents more involved in the planning process and from providing clear information about the road safety potential of the implemented measures. A better understanding of the measures’ potential contribution to increase safety is likely to give a greater acceptance.

    The aim of this study performed by VTI was to learn more about what residents, commuters and truck drivers think of the measures taken along two Swedish country roads.

    Concerning one of the roads the truck drivers were positive to the reconstruction even though their fears concerning lack of respect for the continuous centerline had come true. They were also negative regarding the short distance of the gradient field. They would have appreciated if it had been longer. In addition, they argued for deeper milled rumble strips in order to make vibration and sound more easily felt in heavy vehicles. As it is now the truck drivers hardly notice the rumble strips when passing them with a truck.

    Even though the roads previously had had a high traffic density with many dangerous overtakings and a lot of accidents with wild animals, there was little understanding of the reasons behind the reconstructions. The acceptance for fences to protect from wild animals was high, but the other measures implemented to improve road safety were more difficult to substantiate.

  • 29.
    Arnfelt, Harry
    Statens Väginstitut.
    Kalciumkloridens dammbindningsförmåga vid låg temperatur1948Report (Other academic)
  • 30.
    Arnfelt, Harry
    Svenska Väginstitutet.
    Några undersökningar av sulfitlut1941Report (Other academic)
  • 31.
    Arnfelt, Harry
    Statens Väginstitut.
    Skador på betongvägar uppkomna genom saltbehandling vintertid1943Report (Other academic)
  • 32.
    Arnfelt, Harry
    Statens Väginstitut.
    Snabb bestämning av bitumenhalten i vägbeläggningar1942Report (Other academic)
  • 33.
    Arvidsson, Anna K
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Energieffektiv vinterväghållning: val av driftstandardklass2013Conference paper (Other academic)
  • 34.
    Arvidsson, Anna K
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Kostnader för fotgängarskador vs vinterväghållningskostnader2013Conference paper (Other academic)
  • 35.
    Arvidsson, Anna K
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    RSI: Road Status Information2013Conference paper (Other academic)
  • 36.
    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.

  • 37.
    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.

  • 38.
    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%.

  • 39.
    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%.

  • 40.
    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.

  • 41.
    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.

  • 42.
    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.

  • 43.
    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.

  • 44.
    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.

  • 45.
    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.

  • 46.
    Arvidsson, Håkan
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    HVS-test för skattning av nedbrytningseffekter från den tunga trafikens belastning: SE14, SE18 och SE202014Report (Other academic)
    Abstract [en]

    This publication describes the aim and outcome of the constructions made to estimate deterioration/degradation of roads from the load of heavy traffic. The purpose was to study three constructions with three different wheel-loads (40 kN, 50 kN and 60 kN which corresponds to axle-loads of 8 tons, 10 tons and 12 tons). To minimize the test matrix the idea was to copy older test constructions tested with the wheel-load 60 kilonewton (kN). The outcome was not to full content, especially did the thinner, older constructions differ in the bearing capacity (static plate loading). For the most modern construction (SE14), with totally of 625 millimetre of super structure including 111 millimetre of asphalt layers, that was compared with SE10 and SE11 the differences was acceptable. The wheel load was 40 kN in 600 000 passes and 50 kN for another 600 000 passes, in total 1.2 million passes. Total rut depth became approximately 6 millimetre. The ”medium” construction (SE18) had a super structure of 349 millimetre including 100 millimetre of asphalt layers and it was compared with SE06. The wheel load was 40 kN in 500 000 passes, 50 kN for 400 000 passes and 60 kN in 300 000 passes, in total 1.2 million passes. Total rut depth became just over 11 millimetre. The thinnest construction (SE20) had a super structure of 310 millimetre including 70 millimetre of asphalt layer and it was compared with SE02. The wheel load was 40 kN in 390 000 passes, 50 kN for 170 000 passes and 60 kN in 190 000 passes, in total 0.75 million passes. Total rut depth became almost 21 millimetre.

  • 47.
    Arvidsson, Håkan
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Jämförelse mellan Los Angeles-värde och nedbrytning från hjullast2011Report (Other academic)
    Abstract [en]

    Since 2004 the Swedish Road Administration has had requirements on unbound base layer concerning the resistance to fragmentation, the Los Angeles value. To study how degradation from traffic load is affected by resistance to fragmentation five materials with different Los Angeles values were tested in VTI’s Heavy Vehicle Simulator (HVS).

    The degradation from the wheel load has been recorded by comparing the grain size distribution before and after the HVS test. Some values from the grain size distribution have been used or calculated to easier compare the grading curves with the Los Angeles value, e.g. content of fines (material < 0.063 mm) or the area under the grain size distribution curve.

    There is a clear degradation from the wheel load of the HVS in unbound base layer materials. There is, however, not a clear connection between this degradation and the resistance to fragmentation, Los Angeles value. Therefore it is not possible from this investigation to recommend a new level or category of requirements concerning the resistance to fragmentation on unbound base layer material.

    The most important conclusion is that the method that has been used in this project is working to study the degradation and particle relocation in unbound layers.

  • 48.
    Asp, Kenneth
    Swedish National Road and Transport Research Institute.
    PMS seminarium: Pavement Management System arrangerat av VTI och Veglaboratoriet 15 april 1986 i Oslo1986Conference proceedings (editor) (Other academic)
  • 49.
    Asp, Kenneth
    Swedish National Road and Transport Research Institute.
    Proceeding of road safety and traffic environment in Europe in Gothenburg, Sweden, september 26-28, 19901990Conference proceedings (editor) (Other academic)
  • 50.
    Asp, Kenneth
    Swedish National Road and Transport Research Institute.
    Proceedings of the Conference International forum on road safety research: Bangkok, Thailand, October 25-27, 1995. - Vehicle design for safety - Road safety and vulnerable road user group - Road safety and traffic management - Roadway and roadside design for increased safety1996Conference proceedings (editor) (Other academic)
1234567 1 - 50 of 855
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf