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  • 1. Abed, Ahmed
    et al.
    Bizarro, Diana Eliza Godoi
    Neves, Luis
    Parry, Tony
    Keijzer, Elisabeth
    Kalman, Björn
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Carrion, Ana Jimenez Del Barco
    Lo Presti, Davide
    Mantalovas, Konstantinos
    Buttitta, Gabriella
    Airey, Gordon
    Uncertainty analysis of life cycle assessment of asphalt surfacingsIn: International Journal on Road Materials and Pavement Design, ISSN 1468-0629, E-ISSN 2164-7402Article in journal (Refereed)
    Abstract [en]

    The Life Cycle Assessment (LCA) of asphalt pavements are associated with significant uncertainty resulting from variability in the quantity and impact of individual components, the quality of data for each component, and variability of asphalt durability. This study presents a framework to quantify and incorporate the uncertainty of LCA and asphalt durability data into LCA of asphalt surfacings. The suggested framework includes: estimating the uncertainty of asphalt production processes by the pedigree matrix method, conducting a deterministic LCA, applying Monte Carlo Simulation (MCS) to estimate the probability density functions (PDFs) of the considered impacts using the uncertainty data, deterministic solution, and asphalt durability. This framework was applied to six asphalt mixtures; the results show that there is significant uncertainty in the processes that contribute to the environmental impacts. They also showed that considering asphalt durability and its uncertainty is critical and can significantly change the results and interpretation of LCA.

  • 2. Adesiyun, Adewole
    et al.
    Bezuglyi, Artem
    Bidnenko, Natalya
    Laszlo, Gaspar
    Golovko, Sergyi
    Kraszewski, Cezary
    Krayushkina, Kateryna
    Kushnir, Olexander
    Kuttah, Dina K
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Niska, Anna
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Sörensen, Gunilla
    Swedish National Road and Transport Research Institute, Traffic and road users, Traffic safety, society and road-user.
    Szpikowski, Miroslaw
    Andrezj, Urbanik
    Voloshyna, Iryna
    Vozniuk, Andrii
    Vyrozhemsky, Valeriy
    Short-term Research Visits2014Report (Other (popular science, discussion, etc.))
  • 3.
    Afridi, Muhammad Amjad
    et al.
    KTH, Sverige.
    Erlingsson, Sigurdur
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology. KTH, Sverige.
    Sjögren, Leif
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Municipal street maintenance challenges and management practices in Sweden2023In: Frontiers in Built Environment, E-ISSN 2297-3362, Vol. 9, article id 1205235Article in journal (Refereed)
    Abstract [en]

    The municipal street network acts as a multifunctional asset by providing people, vehicles and public services with a well-functioning infrastructure. To keep it in good condition, optimal maintenance measures are required which would result in an efficient use of taxpayers' money. This paper investigates the street network deterioration processes and the management practices that the municipal administrations have applied in Sweden. The study is based on a survey with Swedish municipalities using questionnaires and complementary interviews. The answers provide insight into a wide range of common pavement distresses and deterioration factors, along with pavement management practices. The study identifies that potholes, surface unevenness and alligator cracking are the most cited challenges, while pavement ageing, heavy traffic and patches are the most noted causes. Similarly, the cold climate and population density are influential factors in pavement deterioration. Allocation of the maintenance and rehabilitation and reconstruction budget is higher in the northern part of the country as well as in densely populated municipalities. Condition data collection and use of commercial Pavement Management Systems (PMS) are limited. Addressing the challenges effectively may be possible through the enhancement of the budget, feasible/clear guidelines from municipal councils/politicians, and reducing the gap between street network administrations and utility service providers.

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  • 4.
    Ahlström, Christer
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Bolling, Anne
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Sörensen, Gunilla
    Swedish National Road and Transport Research Institute, Traffic and road users, Traffic safety, society and road-user.
    Eriksson, Olle
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Andersson, Anders
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle technology and simulation.
    Validating speed and road surface realism in VTI driving simulator III2012Report (Other academic)
    Abstract [en]

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

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  • 5.
    Ahmed, Abubeker
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Carlsson, Håkan
    Swedish National Road and Transport Research Institute, Infrastructure, Measurement technology and engineering workshop.
    Lundberg, Thomas
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Utvärdering av gummiasfalt: provväg E22 Mönsterås : etapp 12019Report (Other academic)
    Abstract [en]

    Laboratory and filed investigations have been carried out to evaluate the performance of rubber modified asphalt test road on E22 Mönsterås.

    The laboratory investigations indicated that there are no significant differences in stiffness and shear modulus between the reference and rubber modified mixtures. The rubber modified mixture however showed slightly lower phase angle compared to the reference mixture which indicate that the rubber modified mixture is more elastic. The rubber modified mixtures also showed lower modulus at lower temperatures and slightly higher modulus at higher temperature which are desired properties for resistance against low temperature cracking and permanent deformation respectively. The fatigue tests indicated that the rubber modified asphalt mixture has slightly better fatigue cracking performance. But the difference is not significant.

    The road surface profile measurements indicated no significant differences between the reference and asphalt rubber sections. It is however early to draw conclusions after one year of traffic therefore additional follow-up of the test sections is needed to draw a conclusion.

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  • 6.
    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.

  • 7.
    Ahmed, Abubeker
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Rahman, Shafiqur
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Erlingsson, Sigurdur
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Iron sand as a frost protection layer: thickness design charts2022Report (Other academic)
    Abstract [en]

    Frost depths and frost heaving calculations were performed to prepare design charts and tables for the iron sand (järnsand) layer thickness design for roads typically used for residential area, parking lots and other low to medium traffic roads, and for ground insulation. 

    A segregation potential based frost design method was employed to generate the design charts and tables. The segregation potential method allows the prediction of both frost heaving and frost penetration depth of a pavement structure for a prescribed winter temperature profile or freezing index. Thus, the iron sand layer thickness design tables/charts for roads were prepared for different levels of maximum permitted heaving criteria of 50, 80, 100, and 120 mm. Whereas for ground insulation, a design chart/table was prepared to eliminate any frost action in the ground. In addition to the frost design calculations, two triaxial tests were conducted to evaluate the bearing capacity of the iron sand material. The limited test results indicated that, the bearing capacity of iron sand is similar to conventional sand both in terms of stiffness as well as permanent deformation behavior.

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  • 8.
    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
    Keywords
    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: 2022-10-21Bibliographically 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
    Keywords
    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: 2022-10-21Bibliographically 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
    Keywords
    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: 2022-10-21Bibliographically 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
    Keywords
    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: 2022-10-21Bibliographically approved
    5. Evaluation of a permanent deformation model for asphalt concrete mixtures using extra-large wheel-tracking and heavy vehicle simulator tests
    Open this publication in new window or tab >>Evaluation of a permanent deformation model for asphalt concrete mixtures using extra-large wheel-tracking and heavy vehicle simulator tests
    2015 (English)In: 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) Published
    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.

    Keywords
    Flexible pavement, Bituminous mixture, Mathematical model, Strain, Simulation, Loading
    National Category
    Infrastructure Engineering
    Research subject
    30 Road: Highway design, 32 Road: Pavement design
    Identifiers
    urn:nbn:se:vti:diva-9307 (URN)10.1080/14680629.2014.987311 (DOI)000349451300010 ()2-s2.0-84922800575 (Scopus ID)
    Available from: 2016-03-03 Created: 2016-03-02 Last updated: 2022-12-09Bibliographically approved
    6. Numerical validation of viscoelastic responses of a pavement structure in a full-scale accelerated pavement test
    Open this publication in new window or tab >>Numerical validation of viscoelastic responses of a pavement structure in a full-scale accelerated pavement test
    2015 (English)In: The international journal of pavement engineering, ISSN 1029-8436, E-ISSN 1477-268XArticle in journal (Refereed) Published
    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.

    Keywords
    Flexible pavement, Viscoelasticity, Unbound base, Loading, Mathematical model, Calculation
    National Category
    Infrastructure Engineering
    Research subject
    30 Road: Highway design, 32 Road: Pavement design
    Identifiers
    urn:nbn:se:vti:diva-9278 (URN)10.1080/10298436.2015.1039003 (DOI)2-s2.0-84929238620 (Scopus ID)
    Available from: 2016-03-07 Created: 2016-03-02 Last updated: 2022-12-09Bibliographically approved
  • 9.
    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 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.

    Download full text (pdf)
    fulltext
  • 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.
    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.

  • 11.
    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.

  • 12.
    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.

  • 13.
    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.

  • 14.
    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.
    Modeling of flexible pavement structure behavior: Comparisons with Heavy Vehicle Simulator measurements2012In: 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 (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.

  • 15.
    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.

  • 16.
    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.

  • 17.
    Ahmed, Abubeker W
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Gudmarsson, Anders
    PEAB.
    Waldemarson, Andreas
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Utvärdering av styvhetsförändring i asfaltmassor med returasfalt, rejuvenatorer och polymerer2020Report (Other academic)
    Abstract [en]

    Using reclaimed asphalt (RA) in new pavements reduces the environmental impact of the new pavement. As the proportion of RA in newly paved asphalt increases, it is important to maintain or improve the quality of the mixture so as not to create an increased maintenance requirement. Rejuvenators and mixing with softer bitumen are used to compensate for the harder aged binder in RA. Rejuvenators reduce the stiffness and brittleness of the bitumen, which improves resistance to cracking. However, the risk of initial deformation associated with the use rejuvenators or mixing with softer binder in RA mixes has not been evaluated.

    The objective of this project was to evaluate the stiffness changes with time of laboratory manufactured asphalt concrete mixtures having rejuvenators or softer bitumen with high percentage of RA. In this project, indirect tensile tests, modal analysis, and shear tests were conducted on five different asphalt concrete mixtures with RA, rejuvenators, and polymers.

    The results showed that there are no significant differences in stiffness change with time between the different mixes was observed within 7 to 21 days after production. However, there is stiffness change with time in the long term. The stiffness modulus and shear testing showed that mixing with soft bitumen, or using rejuvenators result in small differences in stiffness and shear modulus values, respectively. Polymer modified mixes have shown lower shear modulus at low temperatures and higher shear modulus at high temperatures compared to mixes with conventional bituminous binders which increases the resistance to cracking at low temperatures and the resistance to deformation at higher temperature, respectively. Storage and conditioning of the specimens and all measurements were carried out in a laboratory environment; thus, the results represent only the stiffness change that occurs without external influence from climate and traffic.

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  • 18.
    Ahmed, Abubeker W
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Rahman, Mohammad Shafiqur
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Erlingsson, Sigurdur
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Impact of longer and heavier vehicles on the performance of asphalt pavements: A laboratory study2018In: Bearing Capacity of Roads, Railways and Airfields - Proceedings of the 10th International Conference on the Bearing Capacity of Roads, Railways and Airfields, BCRRA 2017, CRC Press/Balkema , 2018, p. 483-490Conference paper (Refereed)
    Abstract [en]

    Historically, Longer and Heavier Vehicles (LHVs) have been permitted to operate in Sweden. Since 1996 and as of the beginning of 2015, the maximum gross vehicle weight of 60 tons and a length of up to 25.25 m have been permitted. The Swedish Transport Administration has decided to further increase the maximum gross vehicle weight to 74 tons and studies are undergoing to evaluate the impact of the proposed LHVs on existing transport infrastructure. To this end, repeated load triaxial tests and indirect tensile fatigue tests were conducted on selected conventional asphalt mixtures to investigate and quantify the impact of single, tandem and tridem axle configurations on permanent deformation and fatigue performances of conventional asphalt pavements. In addition, fatigue tests for selected LHV scenarios were conducted. This paper presents the results of the laboratory tests and simulations conducted. The test results have clearly demonstrated the impact of the different axle configurations on the rutting and fatigue performances of the mixture. Furthermore, such results can explain the significance of axle configuration on modelling the rutting and fatigue performances of asphalt pavements.

  • 19.
    Ahmed, Abubeker W
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Rahman, Mohammad Shafiqur
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Erlingsson, Sigurdur
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Impact of tire types and configurations on responses of a thin pavement structure2018In: Advances in Materials and Pavement Performance Prediction: Proceedings of the International AM3P Conference, 2018, London: CRC Press , 2018, p. 271-274Conference paper (Refereed)
    Abstract [en]

    The objective of this study was to assess the impact of tire and tire configurations on the responses of a thin asphalt pavement structure by means of full-scale tests using a Heavy Vehicle Simulator (HVS). A total of six different types of tires, four single and two dual tire configurations, were investigated. The structure was instrumented to measure tensile strains at the bottom of the asphalt layer and vertical stresses and strains in the unbound base, subbase and subgrade layers. The results indicated that, in general, single tire configurations produced higher tensile strain at the bottom of the asphalt layer and higher vertical stresses and strains in unbound base, subbase and subgrade layers.

  • 20.
    Ahmed, Abubeker W
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Said, Safwat
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Lu, Xiaohu
    Nynäs AB.
    Carlsson, Håkan
    Swedish National Road and Transport Research Institute, Infrastructure, Measurement technology and engineering workshop.
    Pavement performance follow-up and evaluation of polymer-modified test sections2019In: The international journal of pavement engineering, ISSN 1029-8436, E-ISSN 1477-268X, Vol. 20, no 12, p. 1474-1487Article in journal (Refereed)
    Abstract [en]

    Between 2003 and 2006, a test road consisting of several conventional and polymer-modified structures was built on a motorway. Different combinations of styrene–butadiene–styrene (SBS) and ethyl vinyl acetate (EVA) polymer-modified binders were used. The test structures have been in service since then and have been monitored for over 9 years. The resistance of the different types of asphalt concrete mixes to rutting and cracking was measured and predicted. The impact of ageing on the mixes was also evaluated. Although all the sections are in good condition after 9 years of traffic, the predicted differences between the test sections based on the PEDRO (Permanent Deformation of asphalt concrete layers for Roads) approach and laboratory evaluations are noticeable. Lateral wander and transverse profile measurements indicated that studded winter tyre wear contributed to most of the rutting compared to permanent deformation due to heavy traffic. The unmodified mixes exhibited considerable ageing and the SBS-modified mixes were least affected by ageing. Furthermore, the SBS-modified base mix produced significantly better fatigue resistance than the conventional base mix. However, further investigations of the relationships between bitumen and mix properties and further follow-ups of the test sections are recommended to validate the findings.

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  • 21.
    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

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  • 22.
    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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  • 23.
    Andersson, Anders
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Driving Simulation and Visualization.
    Lidström, Mats
    Peters, Björn
    Swedish National Road and Transport Research Institute, Traffic and road users, Driver and vehicle.
    Rosberg, Tomas
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Thorslund, Birgitta
    Swedish National Road and Transport Research Institute, Traffic and road users, Driver and vehicle.
    Framtagning av loktågsmodell för VTI:s tågsimulator2017Report (Other academic)
    Abstract [en]

    Allowing higher speeds for freight trains would provide opportunities for a higher prioritization in the traffic flow by rail traffic management, which in itself is a capacity gain and should generate better flows and higher capacity on the Swedish rail network, especially on the major railways. Simulators are an effective and safe way to investigate the effects of changes in both driver behavior and capacity.

    The purpose of this project was to create capacity-enhancing opportunities and actions by developing a freight train simulator and investigating its possible application areas. The aim of the project was to provide a freight train simulator, consisting of a locomotive and a number of wagons, which can be used in studies to increase capacity through, for example, optimized speed, and thus changing braking profiles, for long trains. The project has delivered knowledge of new test methods, a freight train simulator and a software platform for further testing.

    The project was conducted in three successive stages. In the first phase, a pilot study was carried out with drivers, operators and problem owners, who gave the researchers an understanding of the driving environment. In addition, some of the data needed for the development of the freight train simulator was collected. In the second phase, a freight train (software and hardware) model was developed. Stage three was a validation study together with drivers.

    A Traxx model driver console was purchased from a German manufacturer. The vehicle model was developed from a single unit, Regina type (motorcar train), into a combination of several units. The train in the simulator consists of one or more locomotives and a number of wagons with a total length of up to 750 meters. A locomotive of Traxx model is used. For each device, locomotive and wagon, data is required: length, weight, load, brake, roll and air resistance. In addition, information about noise, driving, braking (re-electrical braking and conventional pneumatic brake) (P-brake), cab equipment and more are added. Currently, the track between Falköping - Jönköping - Forserum is modelled and will be used for ATC trains. The model is configurable using combinations of a locomotive (Traxx) and, currently, four different types of wagons. These can be linked in different combinations.

    Some applications that were discussed at the start of the project were, on the one side, those that could naturally be linked to longer and heavier trains, and, on the other, the ideas that arose because of the equipment purchased. At the Transport Administration winter meeting, a workshop was conducted where further uses were discussed. Among these are applications within education, energy efficient driving or design. Education and certain types of studies could be performed with the existing locomotive model, while others require either validation of parameters or some further development of the model.

    The project has provided knowledge of new test methods, this research report and a product in the form of a freight train simulator and software platform for further testing. The project has also delivered a national resource of simulator software. The software provides for cost-effective testing activities in the freight train domain. A freight train simulator has been developed, which will be valuable as a demonstration tool as well as a platform for training,

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  • 24.
    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.

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  • 25.
    Andersson, Jan
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users.
    Andrén, Peter
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Henriksson, Per
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes.
    Stave, Christina
    Swedish National Road and Transport Research Institute, Traffic and road users, Driver and vehicle.
    Wallén Warner, Henriette
    Swedish National Road and Transport Research Institute, Traffic and road users, Driver and vehicle.
    Varför sker en cykelolycka egentligen: analys av händelser då Hövdingar har löst ut2023Report (Other academic)
    Abstract [en]

    In collaboration with Hövding, data has been collected to highlight how different aspects can explain events where the helmet is deployed. The helmet records accelerations, and when a helmet is deployed, this information is sent to Hövding. They then invited the cyclist to participate in a web- survey and an interview. Thus, to increase our understanding of why bicycle accidents occur, data have been collected from the helmets, from a web-survey and from interviews. A total of 196 participants completed the web-survey while 50 participants were interviewed. In addition, data from the helmets were collected from 355 cyclists, of which 264 have had the helmet deployed.

    One main result is that it is on an ordinary day, during an ordinary journey to or from work, by experienced cyclists that are highly educated. Cyclist were aware of traffic rules and what is happening around them – when "it suddenly happens" and it is not until then the cyclists realize how vulnerable they are. The study shows how a complex pattern emerge from the data sources used to understand why a bicycle accident actually occurs. For example, slippery conditions increase the risk of an event, and if "slippery" is combined with darkness the risk increases even further. The data from the helmets could confirm the results from the web-survey and the interviews, but also demonstrate that the helmet, on journeys which ended with the helmet being deployed, had higher levels of activation compared to journeys where it was not deployed. Furthermore, on trips made after the deployment, the helmet also had lower levels of activation which can be understood as the cyclists adapting their behaviour by, for example, cycling more carefully (but not slower). Finally, the results show differences between conventional and electric bicycles in terms of involvement in events where Hövding was deployed.

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  • 26.
    Andersson-Sköld, Yvonne
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Afridi, Muhammad Amjad
    Skelleftea Municipal, Sweden; KTH, Sweden.
    Nordin, Lina
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Patrício, João
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Lindgren, Åsa
    Swedish Transport Administration, Sweden.
    Johansson, Carl-Martin
    Swedish Transport Administration, Sweden.
    Olofsson, Alexandra
    Swedish Transport Administration, Sweden..
    Andersson, Angelica
    Swedish National Road and Transport Research Institute, Society, environment and transport, Traffic analysis and logistics. Linköping University, Sweden.
    Erlingsson, Sigurdur
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology. KTH, Sweden;University of Iceland, Iceland.
    Development of the SUNRA Tool to Improve Regional and Local Sustainability of the Transportation Sector2022In: Sustainability, E-ISSN 2071-1050, Vol. 14, no 18, article id 11275Article in journal (Refereed)
    Abstract [en]

    To fulfil the global sustainable development goals (SDGs), achieving sustainable development is becoming urgent, not least in the transportation sector. In response to this, the sustainability framework Sustainability National Road Administrations (SUNRA) was developed to contribute to improving the sustainability performance of national road administrations across Europe. In the present study, the framework has been tested, applied and further developed to be applicable for target setting and follow-up at the project level at both the Swedish Transport Administration (STA) and at municipal levels. The aim was a framework relevant for investment, re-investments, maintenance and operation projects and also to make it more user applicable. The study also investigated how the framework can contribute to sustainability, identified drivers and barriers for applying the framework and examined whether the framework can be applied and adapted to projects of different complexities. The adaptations and developments were done in collaboration between researchers and practitioners. The results show that the framework could easily be used and adapted for investment, re-investment, maintenance and operation projects in the planning stage, as well as for small municipal establishments, construction or reconstruction of residential areas and frequent maintenance. The framework contributes to increased awareness on sustainability, and it provides a common structure and transparency on how infrastructure project goals/targets are set and fulfilled. The framework can also be applied to follow the fulfilment of the goals/targets and thereby adapt the project to better fulfil the goals. Identified barriers include the lack of obligations and lack of experience in using sustainability frameworks.

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  • 27.
    Andersson-Sköld, Yvonne
    et al.
    Statens Geotekniska Institut.
    Andersson, Karin
    Chalmers Tekniska Högskola.
    Lind, Bo
    Statens Geotekniska Institut.
    Claesson, Anna (Nystrom)
    Chalmers Tekniska Högskola.
    Larsson, Lennart
    Statens Geotekniska Institut.
    Suer, Pascal
    Statens Geotekniska Institut.
    Jacobson, Torbjörn
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Coal tar-containing asphalt: Resource or hazardous waste?2007In: Journal of Industrial Ecology, ISSN 1088-1980, E-ISSN 1530-9290, Vol. 11, no 4, p. 99-116Article in journal (Refereed)
    Abstract [en]

    Coal tar was used in Sweden for the production of asphalt and for the drenching of stabilization gravel until 1973. The tar has high concentrations of polycyclic aromatic hydrocarbons (PAH), some of which may be strongly carcinogenic. Approximately 20 million tonnes of tar-containing asphalt is present in the public roads in Sweden. Used asphalt from rebuilding can be classified as hazardous waste according to the Swedish Waste Act. The cost of treating the material removed as hazardous waste can be very high due to the large amount that has to be treated, and the total environmental benefit is unclear. The transport of used asphalt to landfill or combustion will affect other environmental targets. The present project, based on three case studies of road projects in Sweden, evaluates the consequences of four scenarios for handling the material: reuse, landfill, biological treatment, and incineration. The results show that reuse of the coal tar-containing materials in new road construction is the most favorable alternative in terms of cost, material use, land use, energy consumption, and air emissions.

  • 28.
    Andersson-Sköld, Yvonne
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Mirzanamadi, Raheb
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Nyberg, Erik
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Erlingsson, Sigurdur
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Torstensson, Peter
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment. Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle Systems and Driving Simulation..
    Göransson, Gunnel
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Nordin, Lina
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Ramverk för att prioritera och bedöma nyttan av klimatanpassningsåtgärder2023Report (Other academic)
    Abstract [en]

    Even if the greenhouse gas emissions are rapidly reduced, the ongoing climate change will result in extensive and costly climate-related events that will occur more frequently. The costs in the Swedish transport sector for such events damaging streets, roads, rail/railways, and other vulnerable parts of the infrastructure are high today and are expected to increase. The consequences of weather-related events are, among other things, reduced accessibility, and increased risk of accidents. To maintain the functioning of the transport system, it is important to undertake risk-reducing measures related both to today's climate, but above all, to manage future climate-related events. It is necessary to ensure the functioning of the transport system during extreme weather events, and during periods of prolonged precipitation, prolonged heatwaves and changing precipitation patterns. It is also important to enable adaptation measures to deal with long-term changes such as rising sea levels which affect the accessibility and lifespan of the infrastructure.

    This report presents a summary of results and a summary of how a framework for evaluating climaterelated impact relationships has been used. Effect relationships refer to identifying, assessing, and evaluating climate-related risks and risk reduction measures. In this report, the focus is on identifying, assessing, and evaluating the effectiveness of climate-related measures. The results is a framework for assessing the effect of risk-reducing measures, i.e., to assess whether it is relevant to implement a measure, when in time it should be implemented and to assess which measure is most relevant to implement. The risks have considered in case studies and include fire risk, risk of accidents on streets and roads due to zero crossings or heat, flooding, erosion and landslides and impact on road construction (rutting, bearing capacity and fatigue), track buckling and risks related to high winds. The tests have included hazard and risk identification, risk analysis, identification, and evaluation of possible measures. Examples of case studies are a torrential rain in Kungsbacka municipality in 2019, erosion-related changes over a long period of time at Österdalälven and calculations of climate impact on the road construction at the E10 at Svappavaara. A case study has also included monetary valuation and sensitivity analysis. The framework has also formed the basis for a discussion regarding climaterelated risks linked to electricity supply.

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  • 29.
    Andersson-Sköld, Yvonne
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Nordin, Lina
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance. VTI.
    SUNRA: Version 20202021Report (Other academic)
    Abstract [en]

    SUNRA (Sustainability: National Road Administration) SUNRA is a decision support tool developed to be used in road projects by setting the level of ambition for different sustainability aspects and following up the work towards these in a structured way. 

    This memo describes how to use SUNRA, followed by a chapter with suggestions on where in the planning process SUNRA can be used, followed by chapters presenting the themes and aspects that are considered within SUNRA and the underlying issues that constitute the result of the updates made in this version. 

    In this version, SUNRA has also been sued against the global sustainability goals as well as the Swedish Transport Administration's interpretation of them in Målbild 2030. SUNRQ aims to use it to contribute to sustainable development with a higher level of ambition than just the legal requirements and other criteria that need to be taken into account. Therefore, for the aspects taken into account, minimum requirements for objectives are the legal requirements that exist and the Swedish Transport Administration's own objectives and policies

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  • 30.
    Andersson-Sköld, Yvonne
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment. Chalmers University of Technology, Sweden.
    Nordin, Lina
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Nyberg, Erik
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Johannesson, Mikael
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    A framework for identification, assessment and prioritization of climate change adaptation measures for roads and railways2021In: International Journal of Environmental Research and Public Health, ISSN 1661-7827, E-ISSN 1660-4601, Vol. 18, no 23, article id 12314Article in journal (Refereed)
    Abstract [en]

    Severe accidents and high costs associated with weather-related events already occur in today’s climate. Unless preventive measures are taken, the costs are expected to increase in future due to ongoing climate change. However, the risk reduction measures are costly as well and may result in unwanted impacts. Therefore, it is important to identify, assess and prioritize which measures are necessary to undertake, as well as where and when these are to be undertaken. To be able to make such evaluations, robust (scientifically based), transparent and systematic assessments and valuations are required. This article describes a framework to assess the cause-and-effect relationships and how to estimate the costs and benefits as a basis to assess and prioritize measures for climate adaptation of roads and railways. The framework includes hazard identification, risk analysis and risk assessment, identification, monetary and non-monetary evaluation of possible risk reduction measures and a step regarding distribution-, goal-and sensitivity analyses. The results from applying the framework shall be used to prioritize among potential risk reduction measures as well as when to undertake them.

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  • 31.
    Andersson-Sköld, Yvonne
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Nordin, Lina
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Polukarova, Maria
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment. 560625-7813.
    Sunra: version 20212022Report (Other academic)
    Abstract [en]

    Sunra (Sustainability: National Road Administration) Sunra is the Swedish Transport Administration’s (STA) decision support tool developed to be used in road projects by setting the level of ambition for different sustainability aspects and following up the work towards these in a structured way. 

    This memo describes how to use Sunra, followed by a chapter with suggestions on where in the planning process Sunra can be used, followed by chapters presenting the themes and aspects that are considered within Sunra and the underlying issues that constitute the result of the updates made in this version. 

    In this version, Sunra has also been sued against the global sustainability goals as well as the Swedish Transport Administration's interpretation of them in Målbild 2030. SUNRQ aims to use it to contribute to sustainable development with a higher level of ambition than just the legal requirements and other criteria that need to be taken into account. Therefore, for the aspects taken into account, minimum requirements for objectives are the legal requirements that exist and the Swedish Transport Administration's own objectives and policies 

    This memo is a compilation of the adaptation and update work made by Sunra version 2018-12-152 within the framework of sub-project 1.12 Sustainable analysis for smart maintenance in the program Mistra Inframaint. The update has been made to enable Sunra to be used both within investment, operation and maintenance projects. Updates have been made with respect to the aspects that are taken into account within the different Themes, within which Themes different aspects are taken into account and to match ongoing working methods within Investment and Operation and Maintenance at the Swedish Transport Administration. In the work on the update, exports from Operation and Maintenance and Investment have been involved.

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  • 32.
    Andersson-Sköld, Yvonne
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Nordin, Lina
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Polukarova, Maria
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Afridi, Muhammad Amjad
    Skellefteå kommun; KTH.
    Erlingsson, Sigurdur
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Nyberg, Erik
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Sunra för lokal och regional infrastruktur: prototypen Sulri : Version 20222022Report (Other academic)
    Abstract [en]

    Sunra (Sustainability: National Road Administration) is a decision support tool developed to be used in road projects by setting the level of ambition for different sustainability aspects and following up the work towards these in a structured way. 

    This memo describes the results of continued development of Sunra adapted for local and regional infrastructure. The result is the prototypes Sulri (Sustainability Local and Regional Infrastructure) and Sulri-frequent. Sulri-frequent is intended to be used for more frequent projects, such as paving existing streets, and Sulri is intended for projects that are a little more complex such as rethinking or replanning such as improving for active travel, climate adaptation of an area or adapting a street, a place or an area to other needs, but Sulri can in principle also be used for more frequent or smaller projects. This report describes a first version of Sulri. The report shows how the tool should be used. Chapter 3 then presents the themes and aspects that are considered within Sulri. Appendix 2 gives the corresponding information for Sulri-frequent. Appendix 1 presents relevant documents and links for the different themes and aspects considered in Sulri.

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  • 33.
    Andersson-Sköld, Yvonne
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Nordin, Lina
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Rosén, Lars
    Chalmers tekniska högskola.
    Polukarova, Maria
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Johannesson, Mikael
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Metod och effektsamband för identifiering, bedömning och prioritering av åtgärder för klimatanpassning av vägar och järnvägar: en förstudie2019Report (Other academic)
    Abstract [en]

    This report presents the results of a feasibility study aimed at developing a methodology to support the transport Agency's planning of climate adaptation measures. The report focuses on the effect relationships for the identification, assessment and prioritization of measures for climate adaptation of roads and railways. The results presented in this report are based on literature studies and interviews with road and rail experts.

    The report takes into account the consequences and risks that are expected to arise from climate-related events, such as the impact that arises from a heavy rainfall and measures that can be taken to reduce the risk and the effect thereof. Knowledge of the likelihood of a particular climate-related event occurring during a given period, as well as the size and type of injury, is required to assess or calculate the risk. The cost of damages is for example the delay costs, and costs of transfer and changes between modes of transport, etc., and recovery costs and injuries to humans.

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  • 34.
    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.

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  • 35.
    Andrén, Peter
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Backgård, Björn
    IT-verktyg för asfaltunderhållsplanering: utveckling och test av prognosverktyg för spårdjup; för vidare integration i stödsystem för underhållsplanering2021Book (Other academic)
    Abstract [en]

    Trafikverket upphandlar numera ofta vägar på totalentreprenad med funktionskrav där en huvudsaklig kravställning görs på tvärgående jämnhet (spårdjup). Denna kontraktstyp kan innebära relativt stora risker för entreprenörer eftersom man redan i anbudsskedet behöver kunna bedöma kostnader för felavhjälpande och underhållskostnader senare under garantitiden. För att kunna bedöma framtida underhållskostnader vid denna typ av kravställning behövs modeller som kan prognostisera spårdjupsutvecklingen. Sådan prognostisering kan antingen ske på olika sätt, t.ex. på övergripande nivå, inte sällan med manuell beräkning i populära kalkylprogram (t.ex. excel), baserat på olika nyckeltal från en eller flera vägar. Ett annat sätt, och som detta projekt utgår från är att på relativt detaljerad nivå utnyttja succesiva data från den aktuella entreprenaden, som skall prognostiseras, vilket kräver årlig data av hög kvalitet, d.v.s. data som filtrerats från förmodade felaktigheter och synkroniserats såväl geografiskt som kronologiskt. Detta projekt har syftat till att utveckla och utvärdera ett sådant verktyg. Denna rapport går igenom utvecklingsprocessen av verktyget och hur man använder det samt förklarar dess uppbyggnad för de huvudsakliga delarna tillsammans med exempelkod i syfte att möjliggöra för aktörer som önskar implementera liknande varianter

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  • 36.
    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.

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  • 37.
    Antonson, Hans
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes.
    Ahlström, Christer
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Wiklund, Mats
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Blomqvist, Göran
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Mårdh, Selina
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Crash Barriers and Driver Behavior: A Simulator Study2013In: Traffic Injury Prevention, ISSN 1538-9588, E-ISSN 1538-957X, Vol. 14, no 8, p. 874-880Article in journal (Refereed)
    Abstract [en]

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

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

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

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

  • 38.
    Anund, Anna
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, The Human in the Transport system..
    Fors, Carina
    Swedish National Road and Transport Research Institute, Traffic and road users, The Human in the Transport system..
    Sjögren, Leif
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Charman, Suzy
    TRL, UK.
    Helman, Shaun
    TRL, UK.
    Deliverable Nr 4 – Consistent treatment in relation to the severity of a curve, a driving simulator study2011Report (Other academic)
    Abstract [en]

    The overall aim of this work is to develop guidelines for evaluation of potential treatments, categorized as “self-explaining treatments” by the use of a driving simulator. More specific the driving simulator study had the aim:

    • • To evaluate the effectiveness of curve treatments, in particular to determine whether a combination of treatments on curves according to their severity could help drivers correctly establish the severity of a curve in advance, and therefore adapt their speed appropriately.

    In total 35 participants, divided into two groups, drove approximately 46 minutes on a rural road with 3 baseline curves without treatment and 9 curves with treatment of varying levels. In total three different treatment levels and three different curves were used. One group received treatments before each curve that correspond to the severity of the curve (slight curve – low treatment level; moderate curve – medium treatment level; severe curve – high treatment level); the other group experienced inconsistent treatments by being exposed to all nine possible combination of curve and treatments.

    The analysis of the effects on speed in average and at each point (v0 to v5) was done with Mixed Model ANOVA. Dependent variables were speed measurements in the different points along the curve (v0 to v5) and the average speed through the total curve (from point v0 to v5). The analyses were done both for absolute speeds and for the relative change in speed from starting point (v0). Independent variables were consistent/inconsistent group; curve (1-3), treatment level (1–3) and time on task, here called order (1–9). Subject was used as random and nested on group. In addition the most severe curve was analysed separately in order to compare the groups.

    In conclusion the result showed that in most cases there were significant effects for treatment levels, severity of the curve, order (time on task), and for subject. There was no significant main effect on group (consistent/inconsistent). However, there was an interaction between curve and group, telling us that the consistent marking significantly reduced the average speed among those with consistent treatment. This holds true also for the speed at point v2, v3 and v5. A final argument for the effectiveness of consistent treatment is that if only the severe curve was considered, there was a significant effect of group.

    Guidelines for evaluation

    It was found that our used method to evaluate the effects of speed adjustment worked well. 35 participants each drove approximately 45 minutes. They were divided into a consistent and one inconsistent group. Three levels of treatment and three severities of curves were used. The dependent variable was the speed measured at three points along the curve. This methodology could be used to evaluate other types of self-explaining treatments. But since a driving simulator study requires a lot of planning (expensive) it is suggested to initially do an expert workshop to evaluate and select the suitable SER treatment and also detailed scenario description.

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  • 39.
    Anund, Anna
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Kecklund, Göran
    Stockholms universitet, Karolinska Institutet.
    Fors, Carina
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Ihlström, Jonas
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Ingre, Michael
    Stockholms universitet.
    Radun, Igor
    University of Helsinki.
    Söderström, Beatrice
    Swedish National Road and Transport Research Institute, Infrastructure, Crash safety.
    Bussförares arbetstider kopplat till trötthet2014Report (Other academic)
    Abstract [en]

    Bus drivers often have irregular working hours and their work involve high levels of stress. These factors can lead to severe fatigue and the purpose of this study is to highlight how the working hours affect sleep, stress, fatigue and driving performance. The project includes four studies: questionnaire, sleep diaries and actigraphy, analyze of rosters and an experiment on real road with bus drivers. The hypotheses were that early morning shift, split shifts, long working hours and short hours of rest between shifts contribute to sleepiness, stress, fatigue and impaired driving performance, which together can result in increased safety. The overall results support these hypotheses. Generally, sleepiness and fatigue while driving are perceived as problems because drivers connect those factors with impaired driving performance, which increases the risk of incidents and accidents. In total 45 percent of all drivers had trouble at least twice a month to stay awake while driving and 19 percent had over the past decade been involved in an incident due fatigue. The experiment with split shift driving support these findings. The report concludes with a list of suggestions.

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  • 40.
    Anund, Anna
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Söderström, Beatrice
    Swedish National Road and Transport Research Institute, Infrastructure, Crash safety.
    Utvärdering av effekten av förstärkt information vid övergångsställe (FIVÖ)2010Report (Other academic)
    Abstract [sv]

    Förstärkt information vid övergångsställe, så kallade FIVÖ-system, är effektivt i termer av att öka fotgängares upplevelse av säkerhet och trygghet vid passage av övergångsstället. Syftet med föreliggande studie var att utvärdera effektiviteten av FIVÖ-systemen samt att fånga fotgängares, cyklisters och förbipasserande trafikanters uppfattning om de klassiska FIVÖ-systemen.

    Studien omfattar en första genomgång av olyckor vid övergångsställen, hastighetsmätningar vid ett urval av platser samt intervjuer med fotgängare, cyklister och bilister som passerar FIVÖ-system. Resultaten visar att flest olyckor vid övergångsställen sker i tättbebyggt område i anslutning till korsningar på vägar där hastighetsbegränsningen är 50 kilometer i timmen. Detta speglar framför allt att det är där det finns övergångsställen. För urvalet av mätplatser visar resultaten av hastighetsmätningarna en signifikant lägre hastighet (~ 2,2 km/h) då FIVÖ-systemet var aktivt jämfört med då det inte finns ett system. Vidare visar resultaten att såväl fotgängare som cyklister upplever att systemen bidrar till att de är säkrare, känner sig trygga och att förbipasserande i större utsträckning stannar och släpper dem före. Bilisterna upplever att systemet bidrar till att de lättare kan upptäcka fotgängare och cyklister vid övergångsstället. Det finns dock en del utvecklingspotential avseende synbarheten. Såväl bilister som fotgängare och cyklister anser att de ljus som används vid testade FIVÖ-system kan förbättras och förstärkas.

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  • 41.
    Anund, Anna
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Human-vehicle-transport system interaction.
    Sörensen, Harry
    Swedish National Road and Transport Research Institute, Infrastructure, Measurement technology and engineering workshop.
    Externt och internt buller samt vibrationer vid körning på sinusräfflor2010Report (Other academic)
    Abstract [sv]

    Studien omfattar en jämförelse av ljudnivåer och vibrationer i fordon vid körning på två typer av räffelutformning, en konventionellt fräst räffla och en sinusformad räffla.

    Mätningar av interna och externa ljudnivåer samt vibrationer i chassi och säte har skett vid körning på fyra sträckor; en sträcka med vanlig fräst räffla (konventionell), vid denna har dels en äldre räffla ingått, dels en nyfräst räffla. Vidare har tre sträckor med sinusformade räfflor ingått.

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  • 42.
    Arvidsson, Anna K
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Energieffektiv vinterväghållning: val av driftstandardklass2013Conference paper (Other academic)
  • 43.
    Arvidsson, Anna K
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Kostnader för fotgängarskador vs vinterväghållningskostnader2013Conference paper (Other academic)
  • 44.
    Arvidsson, Anna K
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Krav för att förhindra fallolyckor: tekniska egenskapskrav för gator och vägar2017Report (Other academic)
    Abstract [en]

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

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

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  • 45.
    Arvidsson, Anna K
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    RSI: Road Status Information2013Conference paper (Other academic)
  • 46.
    Arvidsson, Anna K
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Sträckprognoser E62013Report (Other academic)
    Abstract [en]

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

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  • 47.
    Arvidsson, Anna K
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Sustainability and climate change considerations in winter maintenance2015Conference paper (Other academic)
  • 48.
    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.

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  • 49.
    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.

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  • 50.
    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%.

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