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  • Niska, Anna
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance. VTI.
    Eriksson, Jenny
    Swedish National Road and Transport Research Institute, Traffic and road users, Traffic Safety and Traffic System.
    Taavo, Ellen
    Stockholms stad.
    Sopsaltningens effekt på cykeltrafiken: en analys av cykelflöden och olyckor i Stockholm2019Report (Other academic)
    Abstract [en]

    A winter maintenance method for cycleways becoming widespread in Sweden is “sweep-salting”. The method entails a front-mounted power broom for snow clearance and brine, pre-wetted or dry salt for de-icing. Traditionally in Sweden, ploughing and gritting is used for winter maintenance of cycleways and footways. At VTI the sweep-salting method has been evaluated in several research studies, focusing on the method, equipment and strategies in order to give recommendations regarding the implementation of the method. In the study presented in this report, this research has been complemented with analysis of accident data from Strada, from 2013 through 2017 and the winter seasons 2012/13–2017/18, including cyclists, pedestrians and moped riders as well as cycle flow measurements from Stockholm, with the objective to evaluate the effects of sweep-salting on cyclists.

    All in all, our analyses of bicycle flow measurements from Stockholm show that sweep-salting contributed to increase the winter cycling. The analyses of accident data indicate that sweep-salting has also contributed to reduce the number of accidents due to skidding. Since the sweep-salted cycle routes are generally important for commuting resulting in relatively high cycle flows, it is likely that the accident risk per cyclist is lower after sweep-salting has been introduced. However, the available data was not extensive enough to quantify the effects. Nevertheless, it is clear that sweep-salting has not led to an increased accident risk. Fall accidents among pedestrians represent the major part of the accidents due to skidding and they occurred mainly on sidewalks in the inner city. We have also analysed weather data from VViS stations located along the road network around Stockholm and from one of SMHI's weather stations in Stockholm.

  • Swärdh, Jan-Erik
    Swedish National Road and Transport Research Institute, Society, environment and transport, Transport economics.
    Benefits of noise measure in train commuting suburbs: a comparison of Swedish guidelines and WHO recommendations2019Report (Other academic)
    Abstract [en]

    In this study, we compare different valuation functions for a noise abatement measure in an exploitive train commuting suburb in Sweden. The benefits are estimated with different functions focusing on Swedish guidelines and recent WHO recommendations. The results show that the willingness-to-pay-based estimates of the Swedish guidelines are much lower than the estimates based on WHO guidelines. The main reason for the higher benefit estimates with WHO recommendations is the discontinuous valuation function that leaps from 0 to about 5000 SEK at 49 dB, whereas the Swedish guidelines does not include any corresponding discontinuity in its valuation function. Furthermore, the WHO recommendations are sensitive to night exposure as the cost of sleep disturbance is dominating. These different results of the monetary benefits illustrate the importance of including only established impact functions and valuation functions, and carefully apply them when noise-abatement benefits are calculated.

  • Nyström, Johan
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Transport economics.
    Wikström, Daniel
    Högskolan Dalarna.
    Empirical analysis of unbalanced bidding on Swedish roads2019Report (Other academic)
    Abstract [en]

    Based on anecdotal evidence, claims are made that unbalanced bidding is a major problem in the construction industry. This concept refers to a sealed price auction setting with asymmetric information and unit prices, where information rents are extracted. Theoretical literature has shown that it is rational for an informed contractor to skew unit prices. However, empirical studies on the magnitude of the problem are lacking. As the first quantitative study based on European data, it is shown that unbalanced bidding exists, but in small magnitudes. The result is in line with earlier studies from the US.

  • Jussila Hammes, Johanna
    Swedish National Road and Transport Research Institute, Society, environment and transport, Transport economics.
    Styrmedel för självkörande fordon2019Report (Other academic)
    Abstract [sv]

    Tekniken för självkörande fordon utvecklas snabbt, även om drömmen om helt självkörande fordon fortfarande är relativt osäker. I detta PM görs översikter över flera olika litteraturer. En är en översikt över de effekter som självkörande fordon kan förväntas ha på trängsel, restid, markanvändning och parkering, påverkan på urban sprawl, miljöeffekter och påverkan på energianvändning, trafiksäkerhet samt hälsoeffekter. Självkörande fordon kommer dessutom ha en stor påverkan på självkörande taxi och kollektivtrafiksystem, där flera bedömare anser att det sistnämnda bara kommer kunna existera i sin nuvarande form i tätbebyggda områden. Självkörande fordon kan vidare bidra med ökad och förbättrad mobilitet för grupper så som funktionshindrade, äldre och barn, de påverkar infrastrukturplaneringen, och avslutningsvis har de potential att revolutionera godstransportsystemet. Utifrån en förståelse för hur självkörande fordon påverkar transportsystemet och det omgivande samhället görs sedan en översikt över den litteratur som studerar möjliga styrmedel för att internalisera de externa effekter som självkörande fordon orsakar. Litteraturen omfattar även styrmedel som ska stödja introduktionen av självkörande fordon, även om det inte är klart varför ett sådant stöd skulle behövas, samt vissa styrmedel, framförallt olika typer av vägavgifter, som skulle kunna användas för att internalisera effekter av ökad trängsel. Avslutningsvis relateras både de effekter som självkörande fordon har, och de styrmedel som undersökts till Trafikverkets mål och slutsatser dras gällande behov av framtida forskning.

  • Fors, Carina
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Human Factors in the Transport System.
    Johansen, Trond Cato
    Ramböll.
    Nordic certification system for roadmarking materials: Version 6:20192019Report (Other academic)
    Abstract [en]

    A Nordic certification system for road marking materials was introduced in 2015. The system is basedon documented performance measurements of material samples applied on test fields on public roads.The certification system includes both flat (type I) and structured/profiled (type II) markings, antiskidmaterials (materials with enhanced friction), temporary markings (Denmark only) and inlaid markings(Norway only). From 2019, the certification system will also include materials for hand applicationand materials with enhanced durability for illuminated high-traffic urban areas.

    Material tests are carried out at two test sites: one in Norway and one in Denmark. The tests fields aresituated on public roads and the tested materials are thus exposed to real traffic conditions and toweather conditions representative for the Nordic countries. The materials are followed up byperformance measurements during one or two years. The certification includes requirements oncoefficient of retroreflected luminance RL under dry and wet conditions, luminance coefficient underdiffuse illumination Qd, friction and colour coordinates. The number of wheel passages is measured atthe test sites annually. The certification system includes material identification, which allows forfuture material sampling and analysis.

    The certification system is based on the European standards EN 1824 Road marking materials – Roadtrials, EN 1436 Road marking materials – Road marking performance for road users, and EN 12802Road marking materials – Laboratory methods for identification.

    The report describes the certification system and how it is applied in the Nordic countries. Proceduresand methods that are used for application of materials and performance measurements are specified.

  • Forward, Sonja
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes.
    Henriksson, Per
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes.
    Digitalt utbildningsprotokoll: en pilotstudie av ett verktyg vid privat övningskörning2019Report (Other academic)
    Abstract [en]

    Statistics from the Swedish Road Transport Administration show that less than half of learner drivers pass their driving test. An important explanation for this is that a large proportion of learner drivers who fail their test do not prepare sufficiently for the test. Researchers and professional driver trainers have therefore looked for new solutions and tools which can improve the educational process. A desired effect would be for more people to pass their driving test and thus shorten the waiting times for the test itself.

    The Swedish National Association of Driver Trainers (STR) therefore wondered if a digital education protocol (DUP) could help in reducing the number of re-takes. Thereafter, the development of the protocol started. Firstly, through discussions in a workshop with stakeholders and key persons and then through interviews with supervisors, driver trainer and researchers. In the final DUP, 15 training blocks were included, where text, images and films explained and described an exercise based on the objectives of the national curriculum. Either the private supervisor or the driver trainer could approve a teaching ‘block’, when its goal was considered to be fulfilled.

    In order to establish how DUP has been introduced at driving schools, how it has been used and if it has resulted in fewer re-takes, a ‘process evaluation’ and a before and after study were conducted. Methods used were surveys and a register, which was updated every time a private supervisor reported that they wanted to participate in the pilot study. The driving schools were responsible for recruiting supervisors during their introductory training. Recruitment started late autumn 2015 and lasted until autumn 2017 when more than 350 supervisors took part in the study. According to the register, there were very few participants who, at the beginning of 2017, had approved any of the blocks. In order to find out why a short survey was distributed to the group. The results showed that the large majority had not started to drive with the students, but there were also some who had technical problems. As a result of this evaluation the manual was revised, and information material was produced, which the driving schools could use in connection with supervisors' introductory training. One year later when the recruitment of new supervisors stopped and 369 had registered, a new web survey was sent out.

    This survey measured the effect of DUP but also how it had been used. The response rate was rather low, about 10 percent. Of the responses from 47 supervisors, it appeared that half of them had not noticed the material in the DUP. The main reason for this was that they had forgotten that they had registered an interest in participating, that they had not started to practice driving with their students or that they had changed their minds and no longer wanted to use the tool. Of those who had used the DUP, one third said that the DUP was a great support for them. The tool was used as a source of inspiration but there were only a few who also had approved any of the blocks which would indicate that it was completed. The reasons were, among other things, that the supervisor was unable to use it for technical reasons, that the block was not completed and/or that they saw no point in it. Fourteen percent of the supervisors who answered the survey considered that the DUP should become mandatory for private driver training. While several gave positive feedback on the DUP, some supervisors described the technical problems that had occurred. Some of the supervisors argued that it should be adapted to the mobile phone. The result from this pilot study did not find any significant difference between the groups who used it or those who did not when it came to how many ‘re-tests’ the learner driver had to take before getting his/her license.

    The conclusion from this project is that a training protocol, i.e. DUP, can be helpful for supervisors but that further actions are needed to increase its use. Technically, it needs to be easier to use, no matter which application is being used. Since some considered that the manual was enough, the content should be reviewed and offer such things that a printed manual cannot offer as easily. For example, feedback and links to movies. However, those who participated in this pilot project cannot be considered representative, since the number of ‘re-tests’ was considerably smaller and the number of privately reported tests was virtually non-existent. This means that further actions are needed to attract the group that might be most in need of the support that a DUP can provide. For instance, making DUP a mandatory requirement, which means that DUP must be included in the education. In addition, it is suggested that all blocks must be approved, either by the supervisor or a driver trainer, before a learner driver can registered for the driving test. In order to further strengthen the value of DUP, we recommend that the use of DUP is done in consultation with a driver trainer and that it becomes much clearer that both supervisors and teachers can approve parts.