TØI Vitenarkiv
Not a member yet
668 research outputs found
Sort by
Logistikkmodellen i nasjonal godstransportmodell
Get PDFNasjonal godstransportmodell er et planleggingsverktøy som er utviklet for å kunne beregne effekten på godstransporten av ulike tiltak som for eksempel endringer i vegsystemer, endringer i jernbaneterminaler eller havneløsninger. Norge var relativt tidlig ute i utviklingen av en nasjonal modell, noe som har gitt gode erfaringer fra en rekke prosjekter. Den norske godstransportmodellen er i utgangspunktet en ADA1-modell. Den store tyngden av beregningene skjer på disaggregert nivå med varestrømmer mellom soner, hvor man først tilordner optimale omlastingspunkter i nettverket for hvert av kjedealternativene som kan være aktuelle for denne transporten. Deretter optimaliseres hvert av kjedealternativene kostnadsmessig med hensyn til skipningsstørrelser og valg av transportenheter innenfor hver transportmodus. De siste beregningene gjøres i en del tilfeller iterativt for å ivareta effekten av konsolidering med andre forsendelser på samme transportenhet. Modellen er basert på at transportkjedene velges ut fra hva som gir de laveste kostnadene for transportbrukerne. I artikkelen vises litt mer i detalj hvordan modellen er bygd opp, og det gis en oversikt over erfaringer fra bruk i en rekke prosjekter.publishedVersio
Present and future changes in winter climate indices relevant for access disruptions in Troms, northern Norway
Get PDFA number of seaside communities in Troms, northern Norway, are vulnerable to sudden weather-induced access disruptions due to high-impact weather and dependency on one or few roads. In this paper we study changes in winter weather known to potentially cause access disruptions in Troms, for the present climate (1958–2017) and two future periods (2041–2070; 2071–2100). We focus on climate indices associated with snow avalanches and weather that may lead to for example slippery road conditions. In two focus areas, the most important results show larger snow amounts now compared to 50 years ago, and heavy snowfall has become more intense and frequent. This trend is expected to turn in the future, particularly at low elevations where snow cover during winter might become a rarity by 2100. Strong snow drift, due to a combination of snowfall and wind speed, has slightly increased in the two focus areas, but a strong decrease is expected in the future due to less snow. Events of heavy rain during winter are rather infrequent in the present winter climate of Troms, but we show that these events are likely to occur much more often in all regions in the future.publishedVersio
Bike sharing use in conjunction to public transport: Exploring spatiotemporal, age and gender dimensions in Oslo, Norway
Get PDFBike sharing could provide a key role in a transition towards a less car dependent and more sustainable, healthy and socially inclusive urban transport future. This paper investigates two important prerequisites for bike sharing to fulfil these premises: Does it synergise rather than compete with current alternatives to car-based urban mobility; and is it inclusively accessible across population and spatial segments? Drawing on complete 2016–2017 trip records of the Oslo (Norway) bike sharing system, this paper analyses the potential use of bike sharing for accessing, egressing and interchanging public transport and explores its age and gender dimensions. Bike sharing ridership is substantially higher on routes that either start or end with metro/rail connectivity, whilst controlling for other factors, such as route distance, elevation, urban form, time of day and bike dock capacities. However, our results also reveal that bike sharing – both as a stand-alone system and in conjunction with public transport – is less accessible to, suited to, and used by women and older age groups. Especially gender biases appear profound, multifaceted, and intersected by spatial inequalities favouring central male-dominated employment areas. These findings are discussed to derive policy and design directions regarding multimodal integration, dock expansion, rental limitations, and the introduction of e-bikes, to improve the performance, multimodal integration, gender equality and overall socio-spatial inclusiveness of bike sharing.submittedVersio
Interest-adoption discrepancies, mechanisms of mediation and socio-spatial inclusiveness in bike-sharing: The case of nine urban regions in Norway
Get PDFBike sharing systems are increasingly promoted as a quick, accessible, affordable, and healthy transport alternative in a less car-dependent urban mobility system. The objective of this article is to elucidate the social and spatial inclusiveness of bike sharing, by exploring its intersectionality with user backgrounds and residential contexts, and its mechanisms of mediation by attitudes, mobility resources and daily mobility patterns. Hereto, the paper examines and cross-compares the discrepancies between stated bike sharing interest and reported bike sharing membership, amongst a sample of 3672 residents of urban regions in Norway in structural equation models (SEM). Our results indicate that interest is positively influenced by early adopter characteristics, such as young age, full-time work, environmental consciousness, urban outlook, urban residential locations, and the current adoption of combined bicycle and public transport use. In contrast, reported bike sharing membership is explained more typically as a travel behaviour: with reduced effects of attitudes; enhanced effects of residential urban form and bicycle-public transport use; and additional negative effects of car and bike ownership. The paper concludes by discussing these and other interest-adoption discrepancies across social and spatial categories, to derive policy and research directions for inclusive bike sharing.publishedVersio
I hvilken forstand er det mulig å satse for mye på å bedre trafikksikkerheten?
No full textDette kapitlet drøfter om det på et forskningsmessig grunnlag kan gis et svar på spørsmålet om når samfunnet har gått for langt i retning av å bedre trafikksikkerheten. Fire analytiske perspektiver som kan gi veiledning om hvor mye det bør satses på trafikksikkerhet, sammenlignes. Det første - nyttekostnadsanalyser -sier at det satses for mye på trafikksikkerhet når grensenytten av det minst effektive trafikksikkerhetstiltaket er mindre enn grensekostnaden ved tiltaket. Skal dette fungere i praksis, må det være mulig å beregne grensenytten av trafikksikkerhetstiltak noenlunde presist, noe det ikke er. Det andre perspektivet bygger på sammenhengen mellom inntekt og dødelighet. Det sier at det satses for mye på trafikksikkerhet når dette reduserer ressurser til andre livreddende tiltak så mye at antall dødsfall av andre årsaker øker mer enn nedgangen i antall trafikkdødsfall. Det er i praksis umulig å fastslå når det brukes så mye ressurser at det øker dødelighet av andre årsaker enn trafikkulykker. Det tredje perspektivet sier at trafikantene tilpasser sin atferd slik at et optimalt sikkerhetsnivå oppnås. Dette forutsetter at trafikantene gis riktige incentiver og er fullt informerte og rasjonelle, noe som ikke er tilfellet. Det fjerde perspektivet bygger på en analyse av helsemessige konsekvenser av produksjon av trafikksikkerhetstiltak. Dette perspektivet sier at det satses for mye på trafikksikkerhetstiltak når helsevirkningene knyttet til gjennomføring av tiltakene er negative og mer enn oppveier de positive helsevirkninger av tiltakene. Dette svaret krever noen ganger omfattende analyser for å avgjøre om kriteriet er oppfylt eller ikke. Konklusjonen er at det er vanskelig å gi et forskningsmessig begrunnet svar på spørsmålet om når, eller i hvilken forstand, det satses for mye på trafikksikkerhet.publishedVersio
Cumbersome but desirable—Breaking the code of everyday cycling
Get PDFIntroduction Cycling for transport could integrate physical activity (PA) into daily routines and potentially increase total PA levels. However, for parents with young children, most factors affecting transport mode choice tend to facilitate car use. Greater insight is necessary into reasons for (not) using sustainable transport modes in parents with young children. Therefore, the objective of this study was to explore the experiences, including motives, perceptions, attitudes, and norms, of parents of young children by using an e-bike, a longtail bike, and a traditional bike for everyday travel to the workplace, kindergarten, and the grocery store during the autumn, winter, and spring, in nine months. Methods Semistructured focus group interviews were conducted with 18 parents of young children residing in southern Norway. Parents were recruited through Facebook announcements and direct contact with kindergartens, selected organisations, and companies in the Kristiansand municipality. Data were analysed by systematic text condensation by using NVivo V.11. Results Participants’ experiences were summarised by three main themes: ‘cycling is cumbersome’, ‘cycling reflects the desirable me’, and ‘breaking the cycling code’. Time use, planning, logistics, wet and cold weather, long distances, and no cycling habit were frequently mentioned barriers, and the most notable facilitator was the children’s attitude towards cycling. In general, children loved to cycle and preferred cycling to driving. Additionally, the freedom and independence of cycling were emphasised and valued. Conclusion In challenging weather conditions, parents of young children may experience cycling as cumbersome but desirable, and bike access could increase the feasibility of daily cycling.publishedVersio
Crossing borders and expanding modal shift measures: effects on mode choice and emissions from freight transport in the Nordics
Get PDFConsidering the underachievement on modal shift and environmental objectives for freight transport, scholars and policy makers recurrently ask how more road freight can be shifted to rail and waterborne transport. The current study simulates transport and modal distribution effects for several scenarios in which modal shift policy measures are strengthened, expanded, combined, and harmonized across borders in the Nordics. Found transport effects were then used in an environmental model to assess implications for energy use and emissions of CO2,eq, NOx, and particulate matter, gaining insights into which policy measures are more effective or complement each other, and whether international harmonization might increase effectiveness, and modal shift. From our simulations, a Norwegian ecobonus scheme for rail yields larger modal shift away from road than a similar ecobonus for sea transport. Facilitating longer freight trains yields more modal shift but has high policy costs. Effects of harmonizing policies across Nordic countries vary but can be strengthened by combining different measures. However, even for scenarios with strong policy measures, reductions in CO2,eq emissions do not exceed 3.6% in 2030 while sometimes increasing local air pollution. Modal shift policy should therefore not exclusively be regarded as environmental strategy, although it may contribute to other policy objectives.publishedVersio
Can the impacts of connected and automated vehicles be predicted?
Get PDFElvik, R. (2020). Can the impacts of connected and automated vehicles be predicted? : Artikel. Proceedings from the Annual Transport Conference at Aalborg University, 27(1). https://doi.org/10.5278/ojs.td.v27i1.6212A huge research effort is going on in order to develop connected and automated vehicles. Small-scale trials of automated vehicles in real traffic are already taking place. Can the societal impacts of a transition to fully connected and automated vehicles be predicted? This question has been studied in the Horizon2020 project Levitate. To predict the impacts of connected and automated vehicles, one must first identify and describe potential impacts. A list of 33 potential impacts, classified as direct, systemic and wider was developed. A survey was made of methods that can be applied in order to quantify and predict these impacts. Not all potential impacts can be predicted with any confidence. There is, first of all, large uncertainty about when and how long the transition to connected and automated vehicles will be. It is also impossible to predict some potentially quite important impacts, e.g. whether the transition to automation will be associated with a transition to various forms of shared mobility or whether individual ownership and use of vehicles will continue at present levels. Another important aspect which is difficult to predict is whether automated vehicles will continue to have internal combustion engines or be electric or based on fuel cells. Several methods must be applied to predict the impacts of connected and automated vehicles. As far as impacts on traffic operations are concerned, various forms of traffic simulation have been widely applied. Broadly speaking, connected and automated vehicles are expected to lead to increased road capacity, fewer accidents and less emissions. Increased road capacity may in turn generate induced travel demand, which to some extent will fill up the new capacity. Road safety is likely to be improved, but there is large uncertainty about how non-automated road users and automated vehicles can interact in ways that maintain current safety levels or, preferably, improve safety.Can the impacts of connected and automated vehicles be predicted?publishedVersio
From novelty to normality: reproducing car-sharing practices in transitions to sustainable mobility
Get PDFThis article investigates the role of practices in sustainability transitions. Employing a social practices approach, we analyze the reproduction of car-sharing practices and discuss its role in transitions to sustainable mobility. We assemble data from interviews with 39 households using car sharing in Oslo, Norway, and show three specific ways of reproducing car-sharing practices: (a) FUSS: Frequent, Unplanned, Short-term, and Small-car use, (b) POLL: Planned, Occasional, Longer-term, and Larger-car use; and (c) PERC: Purpose Elected from Range of Cars. After examining contributing factors, especially the role of provider and user contexts, we turn to how car sharing relates to other household practices. We highlight how cardependent activities and substitutes for daily car use contribute to the reproduction of carsharing. We then discuss how the reproduction of a new practice can help to explain the process through which a niche-based practice becomes a regime-based practice in the transition from one mobility regime to a new one. The article shows that by understanding the reproduction of practices as several different performances, a social practices approach can contribute to understanding the normalization of new mobility practices in sustainability transitions.publishedVersio
Would my driving pattern change if my neighbor were to buy an emissions-free car?
No full textAiming to reduce the number of brown (polluting) cars on the road, several countries currently promote the purchase and use of green (emission-free) cars through financial and non-financial incentives. We study how such incentives affect consumers who continue to drive brown cars. Using a simple model, we analyze the effects of policy instruments such as subsidizing green cars, taxing brown cars, and allowing green cars to drive in bus lanes. Car owners are influenced by price incentives as well as by external effects from traffic (such as congestion) both in regular lanes and in bus lanes. An extension of the model also considers how changes in local driving habits affect brown-car driving. We find that subsidizing green cars and allowing them to drive in bus lanes might increase brown-car driving. We also report the results of a recent survey containing questions specifically designed to tap the significance of the model’s core mechanisms. The results are partially consistent with propositions derived from the model. While most brown-car respondents report their driving was unchanged after the implementation of the policies to promote green cars, some – particularly in major cities – report that these policies caused them to reduce or increase their driving. We conclude that some mechanisms in our model are more important than others and that certain mechanisms appear to influence different brown-car drivers in different ways. Overall, it seems that Norwegian policies to promote the transition from brown to green cars have somewhat reduced brown-car driving.acceptedVersio