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  • Svanberg, Lisa
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Transport economics.
    Pyddoke, Roger
    Swedish National Road and Transport Research Institute, Society, environment and transport, Transport economics.
    Policies for on-board crowding in public transportation: a literature review2020Report (Other academic)
    Abstract [en]

    Crowding in public transportation is increasingly perceived as a problem in large cities. Public transport authorities strive to develop policies that manage demand and reduce crowding in the best way. This paper reviews studies of policy instruments aimed at crowding and demand management of public transportation, mainly quantitative studies. The most observed policies are adjustments of fare (including differentiation), frequency, capacity, bus size and in some cases road tolls. The reviewed studies either implicitly represent crowding by the willingness to pay for less crowding or by reduction of occupancy levels. We subdivide papers into studies that model transport scenarios and studies that observe passenger demand, often real-world cases. We use social welfare optimization as reference point for analysis of the study contributions. Studies that observe passenger demand present results limited to the effects on overall demand and generally not in terms of social welfare. Some studies report on price differentiating policies that succeed in reducing peak demand, reductions ranging from 1.2 to 10 percent. Most modelling studies find it optimal for occupancy to decrease, however, some studies find that higher occupancy rates are welfare optimal. Few of the reviewed studies present the costs and benefits directly associated with decreasing occupancy. Few studies present both spatio-temporal distributions of occupancy and include a policy for the reduction of crowding. This suggests that a clearer picture of the severity of on-board crowding, together with a policy to manage crowding would be useful.

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  • Hedström, Ragnar
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Tider i spår för underhållsarbeten2020Report (Other academic)
    Abstract [en]

    The allocation of time for performing engineering works (track possession time) is strongly linked to maintenance and capacity aspects and demands a planning process that links the needs of maintenance companies and train operators for time on the line. The scope and time required for maintenance operations varies greatly depending on the type of maintenance measure being performed, making it less clear-cut than the timetabled requirements of train services.

    The purpose of this project is to study how much track possession time is required to perform various types of maintenance measures on rail infrastructure. The categories of measures on which the project focuses are track replacement; rail replacement; switch replacement and overhead line replacement. The short-term aim is to develop relevant documentation regarding the necessary track possession time for the implementation of maintenance measures. The ability to create the necessary space for maintenance operations is dependent on an understanding of the links between parameters such as the time required to perform a given maintenance measure, the quality of maintenance, work environment and timetabling. This can then be used as the basis for joint discussions between clients, train operators and maintenance contractors regarding how a process or business model that is beneficial to all parties might be developed.

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  • Public defence: 2020-06-02 09:00 Registrera dig här: https://kth-se.zoom.us/webinar/register/WN_vZiy4PpORU2GrLe-nbAwaw
    Lundberg, Joacim
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment. KTH.
    Road Surface and Tyre Interaction: Functional Properties affecting Road Dust Load Dynamics and Storage2020Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Particulate matter is a problem for human health, where several relationships between negative health effects and air pollution has been found, including, but not limited to, respiratory diseases, lung cancer and cardiovascular diseases. In countries where studded tyres are used, for example Sweden, Norway and Finland, and where traction sanding is used, particles from abrasion wear of pavements and crushing of traction sand contribute significantly to PM10.

    The thesis has several objectives, where a broader aim is to investigate the complex road surface and tyre system regarding abrasion wear of pavements and the impact on abrasion wear particles and road dust. The thesis also aims to put these aspects in relation to other, equally complex, aspects coming from or affected by the road surface and tyre interaction which include noise, rolling resistance and friction. This is done through some more specific objectives and limitations described in the thesis. The thesis also has the fundamental aim to act as a starting point to reach a more holistic approach to understand the functional performance of the road surface and tyre interaction which has been done in cooperation with Vieira and the results he publishes in his thesis.

    The road surface and tyre interaction consist of a complex contact system which is affected by both tyre properties and the road surface course properties, including both its inherent material properties and the road surface characteristics, as well as the surrounding environment and any interface consisting of for example water, slush, snow, ice or sand and so on.

    The surface wear course has several functions which is dependent on the inherent material properties. The wear course must resist several degradation processes, including chipping, different types of deformation, different types of cracking as well as abrasion wear due to studded tyres to mention some.

    The surface course construction and the traffic characteristics affect the particle generation, where the surface course properties that govern the resistance against abrasion wear also affect the generation of wear particles.

    Other aspects which are affected by the road surface and tyre interaction is the generation of noise and the rolling resistance. Noise has, as for particles, an negative impact on health and the road surface and tyre interaction is the dominating source from about 15 km/h to 25 km/h for light traffic and from about 30 to 35 km/h for heavy traffic. Several mechanisms generate or amplifies the noise and is connected to the surface characteristics such as the macrotexture. Rolling resistance is the conversion of mechanical energy to heat for a rolling tyre and is affected by both the road surface and tyre deflections and deformations and are affected by the surface characteristics such as unevenness and the macrotexture. The rolling resistance is linked to fuel consumption and in extension to exhaust emissions. Another functional property is the friction which is affected by the road surface characteristics by the micro- and macrotexture.

    There are several measures to reduce road dust loads and PM10. The measures can be either preventive or mitigative. Measures aimed at changing the traffic situation and the tyre usage, changing of the road surface wear course, cleaning of the road surface and dust binding are described.

    Several methods has been used in the studies discussed in the thesis and consist of a large-scale road simulator, the usage of laser measurement systems for determination of road abrasion wear and texture respectively, a prediction model for studded tyre abrasion wear and the NORTRIP model for modelling of non-exhaust particle emissions from road traffic. Also used was a commercial system for traffic measurements and a method for determining the proportion of studded tyre usage. Road dust was sampled and quantified using the WDS (Wet Dust Sampler) method and the collected dust was quantified and characterised using a laboratory method and by using laser granulometry.  Turbidity was used as an approximation of the road dust load.

    Five papers are appended to the thesis. The first paper describes the calibration of the Swedish studded tyre abrasion wear prediction model and the effect it has on the NORTRIP model, in which the abrasion wear model is implemented. The second paper describes the macrotexture of different surface wear courses and how different texture measures could be used to describe the potential dust storage capability. The third paper investigate the WDS-method regarding its performance regarding water and how the water performance theoretically affects potential dust losses. The fourth paper describe the spatial and temporal variation of road dust for six winter and spring seasons in Stockholm, Sweden, for several streets with SMA (Stone Mastic Asphalt) pavements. The fifth paper describe a similar investigation performed in Linköping, Sweden, during one winter and spring season for a double layered porous asphalt and for an SMA which acted as a reference. When applicable, the results from Linköping was compared to those from Stockholm.

    The results showed that the abrasion wear modelling overestimated the abrasion wear by approximately 50% which caused the NORTRIP model to overestimate the contribution from the abrasion wear to the particle emissions, which was not surprising. However, it is not likely that the NORTRIP model gets a decrease of the emissions 50% since the road surface and tyre interaction is complex and several aspects affects the abrasion wear and the resulting generation and storage of road dust, including, but not limited to, polishing of the road surface, increased abrasion wear for wet surfaces.

    The results from the WDS investigation showed that the method seems to function well, given the limitations of the study. The largest water loss was the water retained on the road surface. It also seems like most of the dust is collected. The discussions also consider how the WDS method uses water and the strengths and weaknesses this has compared to dry sampling methods.

    The results from the spatial and temporal variation of the road dust loads in Stockholm showed that there are differences between seasons and there is a difference between the dust loads in the wheeltracks and between wheeltracks. In some cases, differences were seen between the streets with large variations, which could be expected since the road dust load is dependent on the traffic characterization, road operation, deposition of material on the surface and the meteorology.  Another result was that an increasing macrotexture seemed to result in an increase in dust loads. The macrotexture was, generally, lower between the wheeltracks and higher in the wheeltracks, which was not surprising due to the traffic impact on the texture development. The macrotexture was, however, only measured at a single occasion. The repaving of a SMA surface course to a more abrasion resistant SMA surface course resulted in a higher dust load compared the before the repaving, while visual observation of the road surface implied a rougher macrotexture. This could, however, have been affected by an increased abrasion wear which occur during the first winter season due to a higher initial abrasion wear. The results in Linköping showed similar temporal and spatial variations as in Stockholm for the investigated SMA surface course. It was also discussed how the double layered porous pavements construction affect the particle transport processes. In the comparison between Stockholm and Linköping, it was suggested that the dust binding and cleaning in Stockholm affect the dust load since these measures are not performed in Linköping which is possibly reflected in the dust loads in and between wheeltracks.

    How different texture measures could be used to characterize the road surface texture and its connection to the dust load storage was also discussed, including a discussion of which measures that could be used. It is, however, also noted that the measures discussed the measure that should be used is not necessarily discovered yet.

    The discussion also mention the lack of a holistic approach regarding the road surface and tyre interaction which simultaneously consider effect such as abrasion wear particles, noise and rolling resistance. Some measures seem to be of interest to improve at least two aspects simultaneously, for example the usage of a double layered porous pavement or texture optimisation. Different strength and weaknesses are discussed for the different mechanisms affecting the different aspects as well as how some mechanisms should be further studies from other perspectives, for example noise mechanisms which may be interesting from a particle perspective.

    The thesis ends with giving some suggestions for continued research to increase the knowledge. This concern abrasion wear modelling and road dust emission modelling where the road surface texture should be considered. Also suggested is that mechanisms from other aspects of the road surface and tyre interaction, for example those affecting noise, also should be investigated and be used to explain mechanisms related to road dust generation and suspension. Several combined investigations are suggested for studying several aspects from or affecting the road surface tyre interaction simultaneously, including noise, rolling resistance, the road surface characteristics, road abrasion wear, abrasion nwear particles, the road dust loads, the suspension of particles and friction which is required to finally achieve the holistic knowledge required to at least minimise conflicts of interest between different functional properties for road surface courses.

    List of papers
    1. Calibration of the Swedish studded tyre abrasion wear prediction model with implication for the NORTRIP road dust emission model
    Open this publication in new window or tab >>Calibration of the Swedish studded tyre abrasion wear prediction model with implication for the NORTRIP road dust emission model
    2019 (English)In: The international journal of pavement engineering, ISSN 1029-8436, E-ISSN 1477-268XArticle in journal (Refereed) Published
    Abstract [en]

    An experimentally based prediction model of road abrasion wear due to studded tyres is available in Sweden and has been found to work well. However, it has not been validated since 2007, and since then road surfaces and tyre design have developed, and the question has arisen regarding the model’s current validity. The abrasion wear model is used in the NORTRIP emission model (NOn-exhaust Road Traffic Induced Particle emission modelling), and the effect of a recalibrated abrasion wear model on the emission model is shown. In this paper, the abrasion wear model is compared to full-scale field measurements at several recently constructed roads in Sweden to investigate its validity, while also proposing changes to allow for continued use. It is concluded that the model overestimates the wear and an update is suggested. In addition, the impact on NORTRIP emission predictions is briefly investigated. There were also indications that NORTRIP is affected by the abrasion model overestimating the contribution of pavement wear to the particle emissions.

    Place, publisher, year, edition, pages
    Taylor and Francis Ltd., 2019
    Keywords
    Studded tyre, Wear, Abrasion, Dust, Mathematical model, Calibration
    National Category
    Infrastructure Engineering
    Research subject
    30 Road: Highway design, 33 Road: Surfacing; 10 Road: Transport, society, policy and planning, 15 Road: Environment
    Identifiers
    urn:nbn:se:vti:diva-13967 (URN)10.1080/10298436.2019.1614585 (DOI)2-s2.0-85065747784 (Scopus ID)
    Available from: 2019-06-05 Created: 2019-06-05 Last updated: 2020-05-19Bibliographically approved
    2. Texture influence on road dust load
    Open this publication in new window or tab >>Texture influence on road dust load
    2017 (English)In: Proceedings of the 22nd International Transportation and Air Pollution Conferens, 2017, p. 14-Conference paper, Published paper (Refereed)
    Abstract [en]

    The objective of this study was to investigate the connection between pavement texture and the maximum dust load retention at a low speed. One of the main sources of PM (Particulate Matter) in the urban environment is the traffic. Traffic contributes not only to exhaust emissions, but also to direct emission from abrasion wear of pavements, tyres and brakes as well as emission from suspension of available road dust on the road surface. This dust is partially stored in the road surface macro texture. Dust accumulate on the surface due to several different mechanisms and transport phenomena’s. Examples of transport mechanisms affecting the road dust load and thus the storage in the texture include precipitation, evaporation, turbulence from traffic, wetting of the road surface binding particles to it, sanding and crushing of the sand etc.

    Keywords
    Surface texture, Particulate matter, Dust, Macrotexture
    National Category
    Infrastructure Engineering
    Research subject
    10 Road: Transport, society, policy and planning, 15 Road: Environment; 30 Road: Highway design, 33 Road: Surfacing
    Identifiers
    urn:nbn:se:vti:diva-12783 (URN)9783905594676 (ISBN)
    Conference
    TAP - Transportation and Air Pollution
    Available from: 2018-02-09 Created: 2018-02-09 Last updated: 2020-05-19Bibliographically approved
    3. Wet Dust Sampler: a Sampling Method for Road Dust Quantification and Analyses
    Open this publication in new window or tab >>Wet Dust Sampler: a Sampling Method for Road Dust Quantification and Analyses
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    2019 (English)In: Water, Air and Soil Pollution, ISSN 0049-6979, E-ISSN 1573-2932, Vol. 230, no 8, article id 180Article in journal (Refereed) Published
    Abstract [en]

    In northern countries, the climate, and consequently the use of studded tyres and winter traction sanding, causes accumulation of road dust over winter and spring, resulting in high PM10 concentrations during springtime dusting events. To quantify the dust at the road surface, a method—the wet dust sampler (WDS)—was developed allowing repeatable sampling also under wet and snowy conditions. The principle of operation is flushing high-pressurised water over a defined surface area and transferring the dust laden water into a container for further analyses.

    In this paper, the latest version of the WSD is presented together with an evaluation of its performance. To evaluate the WDS, the ejected water amount was measured, as well as water losses in different parts of the sampling system, together with indicative dust measurement using turbidity as a proxy for dust concentration. The results show that the WDS, when accounting for all losses, have a predictable and repeatable water performance, with no impact on performance based on the variety of asphalt surface types included in this study, given undamaged surfaces. The largest loss was found to be water retained on the surface, and the dust measurements imply that this might not have as large impact on the sampled dust as could be expected. A theoretical particle mass balance shows small particle losses, while field measurements show higher losses. Several tests are suggested to validate and improve on the mass balances. Finally, the WDS is found to perform well and is able to contribute to further knowledge regarding road dust implications for air pollution.

    Place, publisher, year, edition, pages
    Springer, 2019
    Keywords
    Particulate matter, Method, Measurement, Apparatus (measuring), Sample (mater), Dust, Repeatability, Prediction, Performance, Evaluation (assessment)
    National Category
    Oceanography, Hydrology and Water Resources
    Research subject
    10 Road: Transport, society, policy and planning, 15 Road: Environment
    Identifiers
    urn:nbn:se:vti:diva-14085 (URN)10.1007/s11270-019-4226-6 (DOI)2-s2.0-85069672194 (Scopus ID)
    Available from: 2019-08-20 Created: 2019-08-20 Last updated: 2020-05-19Bibliographically approved
    4. Road dust load dynamics and influencing factors for six winter seasons in Stockholm, Sweden
    Open this publication in new window or tab >>Road dust load dynamics and influencing factors for six winter seasons in Stockholm, Sweden
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    2019 (English)In: Atmospheric Environment: X, ISSN 2590-1621, Vol. 2, article id 100014Article in journal (Refereed) Published
    Abstract [en]

    Traffic related non-exhaust particulate sources and road dust are an increasingly important source for PM10 air pollution as exhaust sources are decreasing due to regulations. In the Nordic countries, the road dust problem is enhanced by use of studded tyres, causing increased road wear and winter road maintenance including gritting. Efforts to reduce road dust emissions requires knowledge on temporal and spatial road dust load dynamics. The city of Stockholm, Sweden, has therefore financed seasonal (October to May) road dust sampling to be able to optimize their winter and spring time street operation measures for reduced road dust emissions. This work describes the outcome of six seasons (2011/2012–2016/2017) of road dust sampling in five central streets using the VTI wet dust sampler (WDS).The results show that road dust load, expressed as DL180 (dust load smaller than 180 μm) has a seasonal variation with the highest loads (up to 200 g/m2) in late winter and early spring and a minimum (down to about 15 g/m2) in early autumn and late spring. The dust load varies between streets and is depending on pavement surface properties. On a smaller scale the dust load has a high variability across streets due to differences in rates of suspension from different parts of the road surface, with low amounts in wheel tracks and higher in-between and outside the tracks. Between 2 and 30% of the DL180 is smaller than 10 μm and could directly contribute to PM10 emissions. In general, higher road surface texture leads to higher dust loads, but the condition of the pavement (e.g. cracks, aggregate loss) might also have an effect. A new, wear resistant pavement accumulated markedly higher road dust amounts than a several years old pavement. This paper closes with a discussion on the complex relation between road dust load and PM10 concentrations and a discussion on the challenges and comparability of road dust sampling techniques and measures.

    Place, publisher, year, edition, pages
    Elsevier Ltd, 2019
    Keywords
    Dust, Particulate matter, Sampling, Season, Variability, Surface texture
    National Category
    Infrastructure Engineering
    Research subject
    10 Road: Transport, society, policy and planning, 15 Road: Environment
    Identifiers
    urn:nbn:se:vti:diva-13645 (URN)10.1016/j.aeaoa.2019.100014 (DOI)2-s2.0-85061003909 (Scopus ID)
    Available from: 2019-05-17 Created: 2019-05-17 Last updated: 2020-05-19Bibliographically approved
    5. Temporal variation of road dust load and its size distribution: a comparative study of a porous and a dense pavement
    Open this publication in new window or tab >>Temporal variation of road dust load and its size distribution: a comparative study of a porous and a dense pavement
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    (English)Manuscript (preprint) (Other academic)
    Keywords
    Road Dust, Organic fraction, Particle Size Distribution, Temporal Variation, Stone Mastic Asphalt - SMA, Double Layered Porous Asphalt Concrete – DLPAC, Low Noise Pavement
    National Category
    Infrastructure Engineering Environmental Sciences Other Earth and Related Environmental Sciences
    Identifiers
    urn:nbn:se:vti:diva-15249 (URN)
    Available from: 2020-05-19 Created: 2020-05-19 Last updated: 2020-05-19Bibliographically approved
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  • Odolinski, Kristofer
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Transport economics.
    Nilsson, Jan-Eric
    Swedish National Road and Transport Research Institute, Society, environment and transport, Transport economics.
    Samband mellan vägytans kvalitet och fordonshastigheter2020Report (Other academic)
    Abstract [sv]

    I denna studie skattar vi effektsamband mellan vägytans kvalitet och fordonshastigheter. Vi använder ett datamaterial som består av ca 1,9 miljoner hastighetsobservationer på det svenska vägnätet under åren 2012 till 2018, samt information om vägytans tillstånd, vägegenskaper och väder. Resultaten visar att längsgående ojämnheter (mätt via International Roughness Index, IRI) innebär betydande hastighetssänkningar, där exempelvis fordonshastigheten sjunker från 70 till 47 km/h när IRI ökar från 1 till 11 mm/m. Även tvärgående ojämnheter (spårdjup), samt ytskador i form av ökad megatextur och makrotextur påverkar fordonshastigheterna negativt. Resultaten indikerar större hastighetssänkningar jämfört med tidigare studier på svenska vägdata. Ett viktigt bidrag är de skattade sambanden för vägar av sämre kvalitet, då det är främst dessa vägar som är aktuella för reinvesteringsåtgärder. Med exempelberäkningar visar vi de restidseffekter våra effektsamband innebär och därmed vilka restidsvinster en reinvesteringsåtgärd kan skapa.

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  • Andersson-Sköld, Yvonne
    et al.
    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.
    Gustafsson, Mats
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Järlskog, Ida
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Lithner, Delilah
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Maria, Polukarova
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Strömvall, Ann-Margret
    VTI.
    Microplastics from tyre and road wear: a literature review2020Report (Other academic)
    Abstract [en]

    This literature review concerns microplastics from tyre and road wear caused by road traffic. As there is limited knowledge about microplastics in general, and microplastics from road traffic in particular, the Swedish Government commissioned the Swedish National Road and Transport Research Institute (VTI) to, during 2018-2020, develop and disseminate knowledge about microplastics from road traffic. The chapters in this report summarises existing knowledge about microplastics from road traffic with respect to the following aspects: sources, spread and presence; effects on and risk to the environment and human health; characteristics and chemical composition; tyre and road wear; sampling methods; analysis and sample preparation; and measures. The report also includes a chapter with overall conclusions, and a chapter about further research, development and investigation needs.

    The purpose of this report is to provide a basis for reducing the generation and spread of microplastics from road traffic. One aim of the report is to collate and disseminate knowledge about microplastics generated by tyre and road wear, and to review the current level of knowledge. A second aim is to identify knowledge gaps and research requirements in relation to microplastics from road traffic. This literature review is based on a review of scientific articles and reports, as well as technical literature and some information from experts and industry.

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  • Bjurström, Henrik
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Dolk, Ellen
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology. VTI.
    Ballastberoende slitage på asfalt och betong: provning enligt Prall2020Report (Other academic)
    Abstract [en]

    The concrete pavement section on E4 outside Uppsala has a few years after construction shown an accelerating rut depth increase which can not be explained by an increased traffic volume. The contactor’s self inspection protocol shows that aggregates from two different quarries with different rock qualities have been mixed in order to fulfill the ball mill value requirement. The way that the abrasive wear is affected when different proportions of a secondary aggregate quality is mixed into the pavement material is studied in this report. Seven series of laboratory specimens, consisting of asphalt concrete and cement concrete, respectively, with different parts of primary and secondary aggregates are mixed and tested according to Prall to study the resistance to wear due to studded tires. The results show an almost linear change of the abrasive wear when the proportion of the secondary aggregate is changed in the 8–16 mm fraction. It also becomes clear that the aggregates in the 4–8 mm fraction do not affect the resistance to wear.

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  • Almestrand Linné, Philip
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Sundström, Linnéa
    SIS.
    Hjalmarson, Mikael
    SIS.
    Standardisation for electric road systems: a review of ITS standards for the development of electric roads2020Report (Other academic)
    Abstract [en]

    As electric road system (ERS) technologies continue to reach higher levels of maturity, the need for standardisation of the field appears comparable to many other technically oriented areas.

    Standards can not only support industrial production and increase the opportunities for dissemination of innovations, they can also contribute to product safety, reliability, and a certain level of product quality. These are common arguments for standardisation of technologies, and they also apply readily to ERS. Standardisation is moreover essential for the interoperability, compatibility, and competitiveness of ERS, specifically from the perspective of facilitating a faster deployment of electric road systems as a promising future solution to replace the dominant position of fossil powered freight transport. Although currently under discussion, standardisation for ERS is however still only at the initial drafting phase.

    The purpose of this study was to increase knowledge of standardisation to promote the development of electric road systems. During the project a mapping was carried out to create an overview of standards that are directly or indirectly central for ERS in the area of intelligent transport systems (ITS). The study employed a combination of methods including an examination of ERS literature and ITS standards, a stakeholder workshop, and expert reviews of a tentative listing of ITS standards that are potentially applicable to ERS. The main result is a preliminary inventory of 111 ITS standards, including standards for electronic fee collection (EFC), where 99 standards have been deemed as potentially applicable to ERS.

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  • Flötteröd, Gunnar
    Swedish National Road and Transport Research Institute, Society, environment and transport, Traffic analysis and logistics. VTI.
    Waterborne urban mobility: final project report2020Report (Other academic)
    Abstract [en]

    A person-centered multi-modal all-day dynamic transport model prototype of the Greater Stockholm region is developed, with the main objective of providing a system perspective of how waterborne urban mobility interacts with and contributes to urban transportation in its entirety.

    The model prototype is implemented using the MATSim simulation technology and integrates a sketch version of the national travel demand model Sampers, an extract from the national road database, and the complete public transport schedule of the Greater Stockholm study region. The model system represents all-day travel chains per synthetic traveler and hence allows studying how different population segments make (often combined) use of available transportation facilities.

    Even though only coarsely calibrated, the model system generates plausible modal shares and within day travel dynamics. A detailed study of a fictitious new boat line demonstrates the analysis possibilities provided by the model system. Both a base case (without the new line) and a policy case (with the new line) are simulated, using the same synthetic population. This allows identifying all synthetic travelers switching to the new boat line, as well as analyzing how the new line is integrated into their all-day travel patterns.

    The model prototype is set up without dedicated data collection, demonstrating that detailed simulation can reveal detailed structure without an excessive data collection burden. Clearly, the present model prototype is not yet ready for use in daily planning practice. It is, however, demonstrated that the development of a person-centric all-day dynamic transport model is not necessarily by orders of magnitude more complicated than setting up a traditional, much less detailed, continuum flow model.

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  • Strandberg, Lennart
    Swedish National Road and Transport Research Institute.
    Lateral stability of road tankers: Vol. 2 Appendices1978Report (Other academic)
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  • Bjurström, Henrik
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology. VTI.
    Fallskadereducerande beläggning för trafikerbar yta: förstudie2020Report (Other academic)
    Abstract [en]

    Before upcoming procurement of pedestrian and bicycle paths, The Swedish Transport Administration wishes to collect information about fall injury reducing pavements. This pilot study is aimed at collecting knowledge about the evaluation of fall injuries, which material and construction methods there are available, and what the research situation is on the topic. The risk of being injured when falling is mainly evaluated by a standardized method where the deceleration in a head shaped weight is measured when it is dropped on the studied material. The literature shows multiple examples of bicycle path pavements, and different floor material and constructions, with good shock absorbing properties. The greatest challenge is to combine these shock absorbing properties with a durability needed for a bicycle path.

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  • Selander, Helena
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Driver and vehicle.
    Dukic Willstrand, Tania
    Swedish National Road and Transport Research Institute, Traffic and road users, Human Factors in the Transport System.
    Henriksson, Per
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes.
    Neergaard, Karin
    Trivector Traffic.
    Wennberg, Hanna
    Trivector Traffic.
    Säker mobilitet på cykel för ett hållbart åldrande2019Report (Other academic)
    Abstract [sv]

    Det är en stor variation bland äldre cyklister avseende deras funktionsförmåga. Det som påverkar cykling är inte bara ålder utan även den egna fysiken (exempelvis muskelstyrka, rörlighet och balans) samt vanan att cykla. Syftet med projektet var att bidra till ökad och säker cykling bland äldre. Totalt deltog 21 personer (12 kvinnor, 9 män) i åldrarna 67-81 år (medelålder 74 år). Deltagarna fick provcykla tre sorters cyklar; en vanlig damcykel, en elcykel och en elmanövrerad trehjuling. Med hjälp av ett antal olika övningar fick deltagarna testa och utvärdera cyklarnas funktion och stabilitet i olika hastigheter, exempelvis hur lätt/svårt det var att stiga på/av cyklarna, hålla balansen eller att cykla med en tyngre last. Den 2-hjuliga elcykeln och den konventionella cykeln var lika ur prestationssynpunkt på alla områden som undersöktes. Den 3-hjuliga elcykeln fick genomgående sämre omdömen. Förutom cykelövningarna intervjuades deltagarna för att diskutera cykling generellt och vilka barriärer som finns för att öka cyklingen samt vad som krävs för att cykling ska kännas säker. Flera av de mer vana cyklisterna som var uppemot 80 år upplevde inga problem alls vare sig med balans, svårigheter att stiga av och på cykeln, eller trafiksituationen. Andra hade anpassat sin cykling genom att gå över till damcykel, elcykel eller undvek att cykla i stadsmiljö. Alla var överens om att cykling bidrar till fysisk aktivitet och bättre folkhälsa. Deltagarna uppskattade framför allt elcykeln, som ett bra komplement till bilkörning; med elmotor skulle det underlätta att få med sig matvaror och annat till/från hemmet.

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  • Forsman, Åsa
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Traffic Safety and Traffic System.
    Björklund, Gunilla
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes.
    Odolinski, Kristofer
    Swedish National Road and Transport Research Institute, Society, environment and transport, Transport economics.
    Vadeby, Anna
    Swedish National Road and Transport Research Institute, Traffic and road users, Traffic Safety and Traffic System.
    Effektutvärdering av stängsling på järnväg: Pilotprojekt i Region Öst2020Report (Other academic)
    Abstract [sv]

    Trafikverket har under 2010-talet arbetat med en åtgärdsstrategi inom järnvägen som bland annat inneburit att nya stängsel har satts upp längs spåren på utpekade sträckor. Syftet med dessa åtgärder har varit att minska antal personpåkörningar i enlighet med halveringsmålet som innebär högst 55 omkomma i järnvägstransportsystemet år 2020. Det har dock inte genomförts någon mer omfattande utvärdering av stängslingens effekt, delvis på grund av de svårigheter detta innebär. Syftet med den här studien var att analysera stängslingens effekter i Trafikverkets region Öst och, baserat på dessa erfarenheter, bedöma om metoden kan användas nationellt. En viktig del i projektet var att bedöma om de dataunderlag som finns är av tillräckligt bra kvalitet för att en nationell utvärdering ska vara rimlig att genomföra.

    Det finns både principiella och praktiska svårigheter med att beräkna stängslingens effekt. De principiella svårigheterna kan belysas om man jämför med effektberäkningar som gjorts inom vägtrafikområdet och då speciellt 2+1-vägar. En stor skillnad mellan dessa åtgärder är att olyckor på väg till största del är just olyckshändelser som förarna försöker undvika. På järnvägen vet vi att en majoritet av personpåkörningarna är suicid och att personerna alltså själva söker sig till spåren. Det gör att effekten av stängsling kan påverkas av om det finns mindre öppningar i stängslet där personer kan ta sig in, eller om det finns uppehåll/luckor i stängslet på grund av plankorsningar eller annat. Denna skillnad samt andra skillnader som diskuteras i rapporten medför att en stängslad sträcka inte kan ses som en standardiserad åtgärd vilket en 2+1-väg kan göra i större utsträckning och det gör det svårare att få fram ett enhetligt effektmått.

    Trots de principiella svårigheterna som diskuteras ovan kanske det största hindret för att beräkna effekten av stängsling är de praktiska svårigheterna med att skapa ett datamaterial som beskriver järnvägsnätet på ett adekvat sätt. För att kartlägga stängslingens utbredning i järnvägsnätet mer än för enstaka sträckor behöver man använda befintliga databaser. I den här studien har information om stängsling hämtats från Trafikverkets datasystem för information om banrelaterade anläggningar (BIS) och några av de problem som finns är:

    • • Informationen i BIS saknar historik. Det innebär att om det sattes upp stängsel ett visst år så vet vi oftast inte hur det såg ut där innan, dvs. om det fanns ett stängsel som ersattes, eller om det var ostängslat på platsen.
    • Det saknas ofta uppgifter om när stängslet sattes upp och hur högt det är. För de flätverksstängsel som sitter uppe saknas uppgift om höjd för cirka 77,5 procent av sträckan. Problemet med saknade uppgifter om höjd har dock minskat under senare år eftersom stålnätspanel infördes som standard för att förhindra obehörigt spårbeträdande år 2014. Dessa stängsel ska vara drygt två meter höga enligt gällande krav. Även för stålnätspanel saknas dock ibland uppgift om uppsättningsår.
    • En annan typ av information som saknas är hur terrängen ser ut runt spåren. Det kan finnas naturliga hinder i form av bergväggar eller vattendrag eller till exempel industribyggnader som gör att spåren är otillgängliga. Avsaknaden av denna information försvårar analyser av stängslingens effekt.
    • Informationen i BIS om stängslens placering stämmer inte alltid med verkligheten. Detta är känt från tidigare studier och även i denna studie har vi upptäckt vissa avvikelser. Hur stor skillnaden är mellan BIS och verkligheten är dock svår att bedöma.
    • Informationen om stängsling i BIS är inlagd på så sätt att det krävs omfattande databearbetning för att få till ett material som kan användas för effektberäkningar. Förutom att det är tidskrävande ökar det risken för felaktigheter i något steg av datahanteringen.

    De problem med datamaterialet som nämns ovan rör främst stängslingsdata, vilket beror på att detta har upplevts som det största problemet. Det finns förstås även andra möjliga felkällor i materialet. En sådan är personpåkörningarnas placering. Det är viktigt att den angivna platsen för påkörningarna är korrekt, speciellt i förhållande till stängslens placering. Hur väl detta stämmer har dock inte varit möjligt att utvärdera inom ramen för detta projekt.

    Studien är avgränsad till spår mellan driftplatser. Det beror delvis på att driftplatser, som de är inlagda i BIS, ofta är besvärliga att hantera rent praktiskt. Delvis beror det också på att vi valt att inte ta med stationsområden i studien, eftersom dessa utgör en komplex miljö som behöver behandlas separat.

    Det slutliga datamaterialet som analyserna i det här pilotprojektet baseras på består av drygt 120 mil enkelspår och 54 mil dubbelspår. Längs enkelspåren är det 1,5 procent av sträckan som har stängsel på båda sidor och 3,9 procent som har stängsel på ena sidan. Motsvarande längs dubbelspår är 4,7 respektive 11,5 procent. Två typer av analyser har genomförts, en före-efter studie och en tvärsnittsstudie. Ingen av analyserna kunde påvisa någon effekt av stängsling, men resultaten måste tolkas försiktigt på grund av de felkällor som förekommer och eftersom totala antalet personpåkörningar är relativt litet. Resultat från tvärsnittsstudien visade dock att högre befolkningstäthet och fler passerande tåg innebar fler personpåkörningar, vilket var väntat.

    Sammanfattningsvis kan vi dra följande slutsatser från studien.

    • Analyserna i den här studien har inte kunnat påvisa några effekter av stängsling. Det betyder dock inte att effekter inte finns utan det kan bero på brister i datamaterialet och på att studien är begränsad till Trafikverkets region Öst som innebär att dataunderlaget i form av personpåkörningar är relativt litet. Även med detta material har vi dock kunnat påvisa att antal personpåkörningar har ett samband med befolkningstäthet och antal passerande tåg.
    • En uppskalning av pilotstudien i region Öst till nationell nivå är möjlig, men det är inget vi rekommenderar i nuläget med de brister i datakällor som finns idag. Resultaten kommer att bli mycket osäkra och svåra att tolka.
    • För att underlätta för framtida utvärderingar av stängsling, men även andra åtgärder, är det viktigt att dokumentera när åtgärden infördes, detaljer kring dess utformning samt hur det såg ut på platsen före införandet.
    • Även personpåkörningar behöver dokumenteras noggrannare för att bli ett värdefullt verktyg i arbetet med att minska antal personpåkörningar. Alla personpåkörningar bör utredas, helst enligt en mall så att insamlingen blir mer systematisk än idag.
    • Förbättringar när det gäller utredning av personpåkörningarna bör också följas av en regelbunden uppföljning. Det skulle kunna ge bättre kunskap om vilka situationer och miljöer som innebär problem och behöver åtgärdas, samt var förbättringar ses.
    • Slutligen är det viktigt att fokusera på helhetslösningar där man försöker intrångssäkra hela sträckningar. Hur hindrar man intrång från till exempel viadukter eller plankorsningar? Här behöver man också inkludera underhåll av stängslen så att de bibehålls i bra skick.
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  • Wallsten, Anna
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes.
    Paulsson, Alexander
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes. K2.
    Hultén, Johan
    K2.
    Hedegaard Sørensen, Claus
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes. K2.
    Pernestål, Anna
    KTH.
    Almlöf, Erik
    KTH.
    Statlig styrförmåga i framtider med smart mobilitet2019Report (Other academic)
    Abstract [sv]

    Studien syftar till att öka kunskapen om hur statens förmåga att styra mot transportpolitiska mål kan förändras i olika framtider med smart mobilitet. Smart mobilitet kan förstås som ett paraplybegrepp som samlar ett antal olika trender inom transportsektorn och som alla har det gemensamt att de knyter an till digitalisering. Generellt handlar omställningen mot smart mobilitet om två parallella processer: dels en utveckling i riktning mot självkörande och uppkopplade fordon, dels en utveckling i riktning mot nya former av delad mobilitet.

    Analysen har baserats på det svenska transportsystemet men vi bedömer det som troligt att analyserna på en aggregerad nivå kommer vara giltig även i andra länder med liknande transportsystem. Vi konstaterar att staten idag förfogar över en stor mängd styrmedel, och sannolikt kommer många av dagens styrmedel vara aktuella även i en framtid med smart mobilitet. Vissa styrmedel påverkas direkt av smart mobilitet. Primärt styrmedel som drar nytta av uppkopplade fordon. Statens möjligheter är avhängigt deras tillgång till data och syn på sin egen roll att styra transportsystemet. Smart mobilitet kan även mer indirekt påverka styrningskapaciteten för olika styrmedel. Det beror på olika antaganden om trafikens utveckling, exempelvis ökad biltrafik eller mer delad mobilitet. Frågor om samhällets organisation har också stor betydelse. Smart mobilitet aktualiserar t.ex. att staten behöver ha en annan kompetens för att effektivt kunna verka i framtiden.

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  • Vadeby, Anna
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Traffic Safety and Traffic System.
    Anund, Anna
    Swedish National Road and Transport Research Institute, Traffic and road users, Human Factors in the Transport System. VTI.
    Hastigheter på kommunala gator i tätort: resultat från mätningar år 20192020Report (Other academic)
    Abstract [en]

    The aim of the present study is to report the changes between the years 2018 and 2019 concerning driver speed levels and speed limit compliance on main municipality streets. The starting year for the measurement series was 2012, and in 2019 a seventh follow-up was performed. Only the main municipality streets with speed limits between 40 km/h and 70 km/h were included. The measurements were made during the month of September in 23 different municipalities in Sweden.

    The results show that in 2019 the space-mean-speed for all vehicles on the main municipality roads was 47 km/h. With respect to speed violations, overall, 65 per cent of drivers obeyed the speed limit in 2019. The lowest speed limit compliance was found on roads with a speed limit of 40 km/h, where only 48 per cent of the traffic obeyed the speed limit. Furthermore, 72 per cent obeyed the speed limit on 50 km/h roads, 79 per cent on 60 km/h roads, and 70 per cent on 70 km/h roads.

    In conclusion, the space-mean-speeds in urban areas are below the legal speed limit, but the lack of speed compliance remains a problem, especially on streets with speed limit 40 km/h. Primarily, the speed limit compliance on roads with lower speed limits must be improved in order to reach the goal of 80 per cent compliance by 2020.

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