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  • Johansen, Trond Cato
    et al.
    Ramböll.
    Fors, Carina
    Swedish National Road and Transport Research Institute, Traffic and road users, Human Factors in the Transport System.
    Nordic certification of road marking materials in Norway and Sweden 2016–20182018Report (Other academic)
    Abstract [en]

    A Nordic certification system for road marking materials, that applies to the countries of Denmark, Norway and Sweden, was introduced in 2015. In these countries, a documented product approval is required in order to use a road marking material on roads managed by the national road authorities. Product approval is based on monitored and documented performance measurements of material samples applied on test fields on public roads.

    A Norwegian-Swedish test site was established in 2015, where between 43 and 81 materials have been applied yearly. The applied materials are followed up with performance measurements for two years. The materials are approved (certified) in relation to the number of wheel passages they will stand.

    The certification system includes road marking materials for longitudinal road markings in categories with respect to colour (white, yellow), type (type I, type II, antiskid) and thickness (0.4, 0.6, 1.5, 3 and 4 mm).

    The present report documents the follow-up performance measurements that were carried out at the Norwegian-Swedish test site in 2018, i.e. one-year follow-up measurements for materials applied in 2017 and two years follow-up measurements for materials applied in 2016. The performance parameters include the coefficient of retroreflected luminance (RL) under dry and wet conditions, the luminance coefficient under diffuse illumination (Qd), the friction, the chromaticity in daylight, and the chromaticity of retroreflected light (yellow materials, only).

  • Johansen, Trond Cato
    et al.
    Ramböll.
    Fors, Carina
    Swedish National Road and Transport Research Institute, Traffic and road users, Human Factors in the Transport System.
    Nordic certification of road marking materials in Denmark 2016–20182018Report (Other academic)
    Abstract [en]

    A Nordic certification system for road marking materials, that applies to the countries of Denmark, Norway and Sweden, was introduced in 2015. In these countries, a documented product approval is required in order to use a road marking material on roads managed by the national road authorities. Product approval is based on monitored and documented performance measurements of material samples applied on test fields on public roads.

    A Danish test site was established in 2015, where between 13 and 32 materials have been applied yearly. The applied materials are followed up with performance measurements for two years. The materials are approved (certified) in relation to the number of wheel passages they will stand.

    The certification system includes road marking materials for longitudinal road markings in categories with respect to colour (white, yellow), type (type I, type II, antiskid) and thickness (0.4, 0.6, 1.5, 3 and 4 mm).

    The present report documents the follow-up performance measurements that were carried out at the Danish test site in 2018, i.e. one-year follow-up measurements for materials applied in 2017 and two years follow-up measurements for materials applied in 2016. The performance parameters include the coefficient of retroreflected luminance (RL) under dry and wet conditions, the luminance coefficient under diffuse illumination (Qd), the friction, and the chromaticity in daylight.

  • Niska, Anna
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Blomqvist, Göran
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Sopsaltning av cykelvägar: för bättre framkomlighet och säkerhet för vintercyklister2016Report (Other (popular science, discussion, etc.))
    Abstract [sv]

    Sopsaltning av cykelvägar är en metod som skulle kunna bidra till en högre standard på cykelvägarna vintertid. Med metoden kan man undvika problematiken med rullgrus. Några svenska kommuner arbetar i dag med att sopsalta cykelvägar. VTI har gjort utvärderande mätningar av sopsaltning i Stockholms stad som sedan vintern 2013/2014 tillämpar metoden ganska omfattande. De utvärderande mätningarna som VTI har gjort på uppdrag av Stockholms stad finns kortfattat beskrivna i detta häfte.

  • Flötteröd, Gunnar
    Swedish National Road and Transport Research Institute, Society, environment and transport, Traffic analysis and logistics.
    DTA simulation with reduced number of iterations2018Conference paper (Refereed)
    Abstract [en]

    An iterated (day-to-day) dynamic traffic assignment (DTA) is considered. In each iteration, a certain fraction of the totaltravel demand adjusts its travel pattern before the entire demand is loaded onto the (congested) network. It is assumed that thedemand is composed of at least two commodities that exhibit non-identical travel behaviors. The demand changes from oneDTA iteration to the next can then be decomposed into two components: (i)demand exchangesbetween commodities, whichdo not affect the total (aggregate over all commodities) demand pattern, and (ii)demand shifts, which do affect the total demandpattern. Given that there are many (day-to-day) sequences of demand and congestion patterns that lead to the same stationaryassignment, the approach taken here is to minimize congestion variability along this path by favoring, to the extent possible,demand exchangesoverdemand shifts. The underlying intuition is that the resulting reduction in congestion variability andconsequently better predictability of travel times leads to a faster and/or more stable convergence of the assignment.

    The selection of replanning rates in general-purpose DTA simulation packages has, due to the limited tractability of suchsystems, received limited attention in the literature. In deterministic settings, flow averaging schemes according to (variantsof) the method of successive averages are often considered (Liu et al., 2007). In stochastic process assignment, constantreplanning rates may be preferred because these can lead to unique stationary process distributions (Watling and Hazelton,2003). The possibly interesting twist of the approach described here is that it (i) leaves the choice of a global replanningrate (being identical for all commodities) to any available algorithm or expert and then (ii) accelerates the convergence of thesimulation process by deriving commodity-specific replanning rates. Lu and Mahmassani (2007) and later Lu et al. (2009)pursue the same line of thinking but make more specific modeling assumptions (a route swapping assignment that aims atattaining a deterministic user equilibrium) than what is assumed in the subsequently described method.

  • Bernhardsson, Viktor
    Swedish National Road and Transport Research Institute, Society, environment and transport, Traffic analysis and logistics.
    Genomlysning av VQ-samband för tvåfältsvägar: Metodförslag till förbättrad klassificering2018Report (Other academic)
    Abstract [sv]

    Trafikverkets hastighetsflödessamband (VQ-samband) redovisar reshastighet på väglänkar för fordonstyperna personbil (pb), lastbil/buss utan släp (lbu) och lastbilar med släp (lbs) som funktion av totalt trafikflöde. VQ-sambanden delas in i olika klasser baserat på vägtyp, hastighetsgräns etc. och sambanden uppdateras kontinuerligt (vanligtvis i fyraårsintervaller) baserat på nya mätdata.

    Vid den senaste revideringen (2017) visade det sig vara svårt att utifrån tillgänglig information i Nationella vägdatabasen (NVDB) bestämma lämplig VQ-klass. Detta eftersom data i NVDB huvudsak beskriver hur vägen ser ut och inte hur den fungerar ur ett trafikföringsperspektiv. För vissa vägtyper är den nuvarande klassindelningen inte längre lämplig. Exempelvis, för tvåfältsvägar tillämpar Trafikverket idag en uppdelning baserat på vägbredd, men skillnaden i hastighet mellan olika vägbredder verkar mer troligt bero på vilken typ av trafik (kortväga/långväga) som trafikerar breda respektive normalbreda vägar.

    Syftet med detta uppdrag var att genomföra en genomlysning av nuvarande indelning av vägklasser och föreslå en ny vägklassindelning för tvåfältsvägar. I nuläget tillämpas följande förklaringsvariabler för hastighetssamband på tvåfältsvägar:

    • Hastighetsgräns
    • Vägbredd
    • Siktklass

    Först genomfördes en översyn av lämpliga datakällor att inkludera vid bedömning av lämpliga förklaringsvariabler. Vid den senaste revideringen av VQ-sambanden tillämpades enbart data från Trafikverkets trafikmätningssystem (TMS) som synkats mot NVDB. Kompletterande mätningar i form av Trafikverkets mätningar för beräkning av hastighetsindex samt synkning mot databasen Pavement Management Systems (PMSv3) bör kunna tillföra relevant information.

    Baserat på erfarenhet och tillgängliga datakällor, gjordes en översyn av vilka faktorer som antas påverka trafikföringen på tvåfältsvägar. En bruttolista med faktorer identifierades, vilka senare användes som grund för att skapa en enkät som distribuerades till en referensgrupp, beståendes av sakkunniga inom branschen. Referensgruppen bedömde vilka faktorer som ansågs påverka trafikföringen på tvåfältsvägar i störst utsträckning, samt bidrog med direkta förslag till lämpliga förklaringsvariabler.Baserat på resultaten från enkätundersökningen identifierades ett antal förslag på lämpliga förklaringsvariabler, samt hur de skulle kunna extraheras från tillgängliga data. Följande förklaringsvariabler föreslås för hastighetsflödessamband på tvåfältsvägar:

    • Hastighetsgräns
    • Linjeföring
    • Trafiktyp
    • Vägutformning
    • Trafiksammansättning

    Förslagsvis utvärderas ett antal givna kombinationer av dessa förklaringsvariabler baserat på spridningen i datamaterialet för den aktuella grupperingen av förklaringsvariabler. Regressionsanalys kan tillämpas för att bedöma lämplig gruppering.

  • Kjellman, Erik
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Human Factors in the Transport System.
    Fors, Carina
    Swedish National Road and Transport Research Institute, Traffic and road users, Human Factors in the Transport System.
    Lundkvist, Sven-Olof
    Analys av livscykelkostnader för vägmärken med fokus på reflexmaterial2018Report (Other academic)
    Abstract [en]

    It is unknown if the road signs with retroreflective sheeting on Swedish roads meet the current requirements for a performance where good reading and discoverability are the targets. No inventory of road signs on state roads is done and no registry for mounted road signs, date of mounting and quality of signs are available.

    This project aims at analyzing life cycle costs for road signs on state roads through inventory of existing road signs on the state road network. Lifetime is determined by several parameters, but primarily by retroreflection requirements according to the Swedish Transport Administration's document Standard Description for Basic Road Maintenance (SBV) and colour requirements according to SS-EN 12899-1.

    The lifetime was determined by observing approximately 300 road signs in the field. The road signs were randomly selected from the Swedish Transport Administration's regions West and Mid. Information about these road signs, such as year of manufacture, how much light they reflect, what colour coordinates they have and what compass direction they were mounted in were registered. Road signs with five different bottom colours were invented; white (road to local destination in urban area), blue (public road), red (stop), green (road to or on motorway) and yellow (private roads). The signs belong to three different classes; RA1, RA2 and RA3B. The classes differ in terms of the amount of light reflected, where the RA3B reflects most. The costs of road signs, posts and foundations were collected through telephone interviews with five different contractors.

  • Oldbury, Kelsey
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes.
    Isaksson, Karolina
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes.
    Elstation Stockholm C: användares erfarenheter2018Report (Other academic)
    Abstract [en]

    Current discussions concerning the development of sustainable transport often focus on the importance of shared and combined mobility options. In recent years, various types of initiatives have been launched with the intention of promoting the development of such ideas. Urban carpools are one such mode of transport and in Stockholm the electric carpool parking station, directly adjacent to Stockholm’s central train station, has been used as a parking and charging location for the collection and drop-off of both “fixed” and “floating” carpool vehicles during the period October 2016 to December 2017.

    One question of specific importance is how carpools are perceived by users when trying to understand the role this type of initiative plays in achieving sustainable mobility. This report presents the results of a focus group interview study conducted with a selection of people who have used various carpool services at the Stockholm Central electric carpool station.

    The purpose of the study was to gain a deeper the insight into the users' perspectives and experiences of carpool services in general, and more specifically how they experienced the electric carpool station at Stockholm’s Central station.

    The results from this study confirm a common aim for the development of carpool services, namely that this type of service should allow people to refrain from owning a car. However, our material also indicates that there are still practical barriers that make it difficult for specific groups to use a carpool, such as families with small children. These practical challenges need to be developed and overcome in order to encourage increased usage of carpools and car sharing services.