| 1. |
- Jenelius, Erik, Docent, 1980-, et al.
(författare)
-
Dynamiska trängselindex
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Under det senaste decenniet har nya datakällor, så som GPS‐data från taxibilar och storskaliga system av fasta detektorer, gett betydligt större möjligheter att kartlägga hur trängseln varierar i en stad, d.v.s. variation mellan gator och områden, olika tidpunkter på dagen och mellan olika månader eller år.På den teoretiska sidan har det, under ungefär samma tidsperiod, upptäckts ett samband mellan fordonstäthet och hastighet på områdesnivå, vilket kallas det makroskopiska fundamentaldiagrammet (MFD). Tidigare har detta samband uppmätts på länknivå och kallas då fundamentaldiagram (FD). MFD kopplar samman antalet fordon i ett område med den genomsnittliga hastigheten ellerflödet i området. Man har också visat att MFD under ideala förhållanden är enegenskap hos nätverket i sig (infrastruktur och trafikstyrning), d.v.s. det beror inte på efterfrågan.I denna rapport använder vi dessa nya trafikmätningsmetoder och teoretiska framsteg inom MFD för två syften. För det första beskriver vi hur trängseln varierar över dagen på Södermalm och i City‐området i Stockholm genom att titta på MFD från empiriska datakällor så som GPS‐data från taxi‐bilar, slangmätningar och restidskameror. För det andra jämför vi simulerat MFD för City‐området med empiriskt MFD för samma område. Detta för att validera hurväl City‐modellen framtagen med simuleringsverktyget Transmodeler kan återskapa trängselsituationen på områdesnivå.Rapporten visar att väldefinierade MFD existerar både för Södermalm och Cityområdet.MFD visar att hastigheten sjunker och fordonstätheten ökar undermorgonens och eftermiddagens rusningstimmar, men trängselnivåerna når inte den punkt där flödet börjar avta trots att fordonstätheten ökar (hyperträngsel). Det är således trångt i innerstaden under rusningstimmarna, men kapaciteten i nätverket räcker ändå till. De två stora lederna Stadsgårdsleden och Sveavägen visar dock tecken på hyperträngsel om fundamentaldiagram skapas separat för dessa leder.Vidare visar rapporten att MFD har stor potential som verktyg för att valideraen simuleringsmodell. I rapporten jämförs MFD från City‐området i Transmodeler med empirisk MFD för samma område. Simuleringsmodellen överskattar flöde och hastighet vid låg densitet. Vid hög densitet ändras dockbilden och simuleringsresultaten underskattar flöde och hastighet. Det verkarsom att kapaciteten i nätverket underskattas, vilket ger högre trängsel imodellen än i mätdata. MFD från Transmodeller visar lägre flöden underavvecklingen av rusningen än under uppbyggnaden, både under förmiddag och eftermiddag, vilket inte syns i de empiriska data. Detta tyder på att det finns stora kö‐problem i simuleringsmodellen, vilket man inte ser tecken på i empiriskt MFD.
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| 2. |
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| 3. |
- Jenelius, Erik, 1980-, et al.
(författare)
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Validation of Traffic Simulation Models Based on the Macroscopic Fundamental Diagram
- 2017
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Ingår i: Transportation Research Procedia. - : Elsevier. - 2352-1465. ; , s. 561-568, s. 561-568
-
Konferensbidrag (refereegranskat)abstract
- Urban traffic simulation models could benefit significantly from new validation methods with potential to reduce the time-consuming calibration and validation work needed before application of the model to evaluate city infrastructure or policy implementations. Current practice is to validate simulation models locally through comparison with point flow measurements and travel times on some important routes. However, for many applications, the level of congestion in an entire area is important. During the last decade, several studies have found empirical evidence of a relation between flow and density on city district level, the existence of a so-called macroscopic fundamental diagram (MFD). This paper shows how the MFD can be used to validate results from a traffic simulation model for a city district. Furthermore, the paper shows empirical results for Stockholm, Sweden.
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| 4. |
- Andersson, Angelica, et al.
(författare)
-
Long-distance mode choice estimation on joint travel survey and mobile phone network data
- 2024
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Ingår i: Sammanställning av referat från Transportforum 2024. - Linköping : Statens väg- och transportforskningsinstitut. ; , s. 91-92
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Both survey data and mobile phone network data are associated with benefits and limitations. Mobile phone network data is limited in its lack of ground truth for the bus and car split, in the lack of socio-economic information about the traveller, as well as in the lack of information about trip purpose. Survey data on the other hand nowadays often has too few observations to obtain significance in important parameters, and it is unlikely that they capture a representative sample of the population. In this paper we investigate to what extent combining the two data sources for mode choice demand model estimation can mitigate the challenges present when only using a single data source, as well as to what extent the estimation can be improved by adding variables unique to the survey data. We also provide recommendations for data collection and combination for future mode choice demand models and analyse policy implications of the estimated results. We show that in our case the business cost parameter becomes insignificant when basing the estimation on survey data only. The business cost parameter is important to compute values of travel times which are relevant for social cost benefit analyses. A benefit of combining the two data sources is that we can both identify latent class variables which capture the correct business group in the latent class structure of the mobile phone network data, and simultaneously obtain better estimates of those variables based on observations from the survey data. Most of the elasticity results in this paper are on par with previous studies; however our results suggest higher cross-elasticities in response to train travel time than what has previously been observed, which could have implications for the social valuation of investments in high speed rail. In this paper we have shown that the proposed method of data combination is indeed valid, and that by combining the two data sources we can mitigate the limitations of each separate data source and thus maintain good quality mode choice demand forecasting models, even in the face of declining survey response rates.
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| 5. |
- Andersson, Angelica, et al.
(författare)
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Long-distance mode choice model estimation using mobile phone network data
- 2022
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Ingår i: Journal of Choice Modelling. - : Elsevier. - 1755-5345. ; 42
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Tidskriftsartikel (refereegranskat)abstract
- In this paper we develop two methods for the use of mobile phone data to support the estimation of long-distance mode choice models. Both methods are based on logit formulations in which we define likelihood functions and use maximum likelihood estimation. Mobile phone data consists of information about a sequence of antennae that have detected each phone, so the mode choice is not actually observed. In the first trip-based method, the mode of each trip is inferred by a separate procedure, and the estimation process is then straightforward. However, since it is not always possible to determine the mode choice with certainty (although it is possible in the majority of cases), this method might give biased results. In our second antenna-based method we therefore base the likelihood function on the sequences of antennae that have detected the phones. The estimation aims at finding a parameter vector in the mode choice model that would explain the observed sequences best. The main challenge with the antenna-based method is the need for detailed resolution of the available data. In this paper we show the derivation of the two methods, that they coincide in case of certainty about the chosen mode and discuss the validity of assumptions and their advantages and disadvantages. Furthermore, we apply the first trip-based method to empirical data and compare the results of two different ways of implementing it.
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| 6. |
- Andersson, Angelica, et al.
(författare)
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Long-distance mode choice model estimation using mobile phone network data
- 2022
-
Ingår i: Journal of Choice Modelling. - : Elsevier. - 1755-5345. ; 42
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper we develop two methods for the use of mobile phone data to support the estimation of long-distance mode choice models. Both methods are based on logit formulations in which we define likelihood functions and use maximum likelihood estimation. Mobile phone data consists of information about a sequence of antennae that have detected each phone, so the mode choice is not actually observed. In the first trip-based method, the mode of each trip is inferred by a separate procedure, and the estimation process is then straightforward. However, since it is not always possible to determine the mode choice with certainty (although it is possible in the majority of cases), this method might give biased results. In our second antenna-based method we therefore base the likelihood function on the sequences of antennae that have detected the phones. The estimation aims at finding a parameter vector in the mode choice model that would explain the observed sequences best. The main challenge with the antenna-based method is the need for detailed resolution of the available data. In this paper we show the derivation of the two methods, that they coincide in case of certainty about the chosen mode and discuss the validity of assumptions and their advantages and disadvantages. Furthermore, we apply the first trip-based method to empirical data and compare the results of two different ways of implementing it.
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| 7. |
- Andersson, Angelica, et al.
(författare)
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Mode Choice Latent Class Estimation on Mobile Network Data
- 2024
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Ingår i: SSRN Electronic Journal. - : Elsevier BV. - 1556-5068.
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- In this paper we use a nested latent class logit specification to define and estimate a large-scale mode choice demand forecasting model. We estimate this model based on mobile phone network data translated to roughly 100 000 long-distance trips within Sweden, achieving convergence of the model and credible parameter estimates. We develop methods to address two problems stemming from the nature of this data: the difficulties of distinguishing bus trips from car trips (since they share the same infrastructure) and distinguishing business from private trips (since trip purpose is unknown). To address the first issue, we estimate a nested logit model with an artificial nest that accounts for the differences in utility between bus and car. To address the latter issue, we estimate a latent class model, identifying classes of trips interpreted as private and business trips. Addressing these two issues substantially improves model fit.
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| 8. |
- Berglund, Svante, 1967-, et al.
(författare)
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Anslutningsresor : en deskriptiv analys
- 2020
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Den här rapporten är en del i ett forskningsprojekt där vi studerar det svenska anslutningsresandet. Här beskrivs anslutningsresor med data från svenska nationella resvaneundersökningen. Ungefär 35 procent av alla långväga (mer än 10 mil) resor sker med ett färdmedel som förutsätter en resa till en station eller flygplats. De flesta långväga resor har en mycket enkel struktur med korta anslutningsresor till huvudfärdmedlet. Det är ovanligt med fler färdmedel under en resa förutom huvudfärdmedel, anslutande och avslutande färdmedel. Anslutningsfärdmedel och huvudfärdmedel är enkelt identifierbara i data. Det råder också en stor symmetri mellan utresa och återresa avseende både huvudfärdmedel och färdmedel för anslutningsresa. För flygresor utgör anslutningsresan ofta under 10 % av resans totala längd men 30% till över 50 % av reseuppoffringen. Anslutningsresan utgör således en signifikant del av den totala reseuppoffringen både i tid och pengar för flyg medan restiden och biljettkostnaden för tåg är en mer komplett beskrivning av hela resan. Resor med tåg startar och slutar ofta i stadsmiljö med närhet till många målpunkter och relativt stort utbud av kollektivtrafik. Det råder därmed en asymmetri i beskrivningen av reseuppoffringen mellan flyg och tåg när man inte tar hänsyn till anslutningsresan.
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| 9. |
- Börjesson, Maria, 1974-, et al.
(författare)
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Assessing the welfare effects of congestion charges in a real world setting
- 2014
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Ingår i: Transportation Research Part E. - : Elsevier BV. - 1366-5545 .- 1878-5794. ; 70, s. 339-355
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Tidskriftsartikel (refereegranskat)abstract
- The standard textbook analysis shows that drivers as a group lose from congestion charges. However, it omits taste heterogeneity, shorter travel times far out in the larger network arising from less blocking back of upstream links and the possibility for drivers to reschedule. Taking account of these factors, using a dynamic scheduling model with heterogeneous users we find that all three add significantly to the benefit of the Stockholm congestion charges and that drivers as a group benefit from these charges even without recycling of revenues. This paper also provides an update on the consumer benefits of the Stockholm charges.
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| 10. |
- Börjesson, Maria, 1974-, et al.
(författare)
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Estimating welfare effects of congestion charges in real world settings
- 2012
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- According to the standard textbook analysis, drivers as a group will be worse off with congestion charging if not compensated by revenues. This result is confirmed by an analysis of the Stockholm congestion charging scheme using a static model with homogeneous users. However, both this static model and the standard textbook analysis omit three important factors: taste heterogeneity, effects of charges on the larger network arising from less blocking back of upstream links and the possibility for drivers to reschedule. Taking account of these factors, using a dynamic scheduling model with heterogeneous users estimated and calibrated for Stockholm, we find that drivers as a group benefit from the charging scheme in Stockholm without recycling of revenues. This paper further investigates the importance of the three mentioned factors. We find that all three factors add significantly to the benefit of the charges and that the most important is heterogeneity in the value of travel time savings. This paper also provides an update on the consumer benefits of the Stockholm charges.
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| 11. |
- Börjesson, Maria, 1974-, et al.
(författare)
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The Gothenburg congestion charge : Effects, design and politics
- 2015
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Ingår i: Transportation Research Part A. - : Elsevier BV. - 0965-8564 .- 1879-2375. ; 75, s. 134-146
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Tidskriftsartikel (refereegranskat)abstract
- This paper summarizes the traffic effects of the Gothenburg congestion charges introduced in 2013. The system is similar to the system introduced in Stockholm in 2006; both are designed as time-of-day dependent cordon pricing systems. We find that many effects and adaptation strategies are similar to those found in Stockholm, indicating a high transferability between smaller and larger cities with substantial differences in public transport use. However, there are also important differences regarding some of the effects, the accuracy of the model forecasts and public support arising from different topologies, public transport use, congestion levels and main objectives communicated to the public. Finally, the Gothenburg case suggests that whether congestion charges are introduced or not depends on the support among the political parties, and that this is determined primarily by the prevailing institutional setting and power over revenues, and to a lower extent by the public support, and benefits from congestion reduction.
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| 12. |
- Börjesson, Maria, 1974-, et al.
(författare)
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The Swedish congestion charges : Ten years on
- 2018
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Ingår i: Transportation Research Part A. - : Elsevier Ltd. - 0965-8564 .- 1879-2375. ; 107, s. 35-51
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Tidskriftsartikel (refereegranskat)abstract
- Time-of-day dependent cordon-based congestion charging systems were introduced in Stockholm in 2006, and in Gothenburg in 2013. The Stockholm system was significantly extended in 2016, and the peak charge has been increased in the two cities. This paper analyses the effects of the first decade with the Swedish congestion charges, specifically effects of the system updates, and draws policy lessons for the years to come. Should we introduce congestion charges in more cities? Should we extend the systems that we have? We synthesize previous research findings and focus on the long-term effects that have varied over time including the recent years: the price elasticities on the traffic volume across the cordon, the revenue and system operating cost, the public and political support, and consequences for the transport planning process. We also explore the effects on peak and off-peak, and different types of traffic (trucks, company cars and private passenger cars), because of access to novel data that make this analysis possible. We find that the price elasticities have increased over time in Stockholm, but decreased in Gothenburg. We find that the public support increased in the two cities after their introduction until the systems were revised; since then, the public support has declined in both cities. We find that the price elasticity was substantially lower when the charging levels were increased, and when the Stockholm system was extended, than when the charges were first introduced, a likely reason being that the most price-sensitive traffic was already priced off-the road at the introduction.
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| 13. |
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| 14. |
- Ekström, Joakim, 1980-, et al.
(författare)
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Simulation based optimisation of toll levels in urban road traffic networks
- 2014
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- There has recently been a growing interest in analysing road pricing schemes in urban areas using dynamic traffic assignment (DTA) tools. The motivation behind this development is the problem for static transportation models to accurately predict travel time savings, from introducing road pricing, in networks with severe congestion. Finding optimal toll levels and locations in urban road traffic networks has so far mainly been studied using either derivative-free heuristics (e.g. genetic algorithms and simulated annealing) or ascent methods. Both approaches rely on fast computations of the road users response (traffic flows, travel times and demands), given the road pricing scheme, and for the case of ascent methods, the methods also rely on fast computations (or rather approximation) of derivatives. Using DTA tools for evaluating the road users’ response to a pricing scheme is, however, very computationally expensive. Previously developed methods are therefore not suitable to use together with DTA.Surrogate models, e.g. in terms of response surfaces, are commonly used for optimisation problems with expensive-to-evaluate objective functions. The surrogate model is used for approximating the expensive-to-evaluate objective function, and the optimisation is then done on the surrogate model instead. The performances of optimisation methods based on surrogate models are, however, dependent on experimental design, infill strategy and choice of surrogate model itself. The experimental design will give the initial set of toll levels, for which the DTA needs to be evaluated, the infill strategy determined additional toll levels to be evaluated by the DTA, and the choice of surrogate model will give the functional form to be fitted to the sampled toll levels.We apply a surrogate model framework for optimising toll levels in a multiple cordon pricing scheme. In the first stage we evaluate the experimental design, infill strategy and choice of surrogate model, using a static macroscopic traffic model. This allows a large number of experiments to be carried out, which would not be possible with a DTA tool. It also allows us to compare the performance of the surrogate modelling approach with other global optimisation methods. In the second stage, the insight which has been gained from the experiments with the static model is used when applying the surrogate modelling approach to a DTA model of Stockholm.Computational results are presented for a Stockholm network with three cordons, each with differentiated toll level in both directions, resulting in a total of six toll level variables. Surrogate models in the form of Radial Basis Functions and Kriging models are evaluated with a static model of Stockholm, for different initial experimental designs, infill strategies and choice of surrogate models. In comparison with previously developed derivative based methods for static models, our results show that the surrogate based optimisation approach performs better, since it allows for metaheuristic methods to search for global optimal solutions efficiently.
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| 15. |
- Ekström, Joakim, 1980-, et al.
(författare)
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Surrogatbaserad optimering av avgiftsnivåer i trängselavgiftssystem
- 2015
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Trängselskatt finns idag i både Stockholm och Göteborg, och det är troligt att utformningen av dessa trängselskattesystem kommer att justeras framöver med avseende på avgiftsnivå, placering och tidpunkt. För Stockholm finns beslut om ändring från januari 2016 och i Göteborg ändrades avgiftsnivåerna i januari 2015. I detta projekt utvecklas metoder som ska kunna ge stöd vid justering av avigiftsnivåer, så att en så stor samhällsekonomisk nytta som är möjligt uppnås med trängselskattesystemet.För storstadsområden, där det under rusningstrafik är trängsel i delar av nätverket, är trängselskatt främst intressant att analysera med dynamiska transportmodeller. Tidigare utveckling av metoder för optimal avgiftssättning har dock främst fokuserat på statiska modeller, exempelvis Emme, som har kända problem med att korrekt uppskatta förändring i restider när det är trängsel i delar av trafiknätverket. I detta projekt har vi därför tillämpat surrogat-baserad optimering, som är en metodansats som ställer få krav på vilken transportmodell som används. Den dynamiska transportmodellen Regent/VisumDUE finns sedan tidigare implementerad för Stockholmsregionen, och har därför även använts i detta projekt. VisumDUE är en makroskopisk nätutläggningsmodell med dynamiskt ruttval, och Regent är en efterfrågemodell som innehåller resgenerering, färdmedelsval och destinationsval för arbetsresor[1].Surrogat-baserad optimering erbjuder ett ramverk för optimering av problem med beräkningsmässigt kostsamma målfunktioner. Genom att approximera en funktionsyta till samplade punkter från den kostsamma målfunktionen, kan optimeringen istället göras över den approximerade funktionsytan. För Regent/VisumDUE tar utvärderingen av ett givet trängselskattescenario ca tio timmar, och det är denna beräkningstid som gör målfunktionen kostsam. Givet ett antal samplade punkter, görs ytterligare sampling utifrån en given strategi för att förbättra approximationen, så kallad iterativ sampling. Inom ramverket finns dock en mängd möjligheter för hur de olika komponenterna designas. Därför är det svårt att utvärdera surrogat-baserad optimering med endast Regent/VisumDUE. En statisk transportmodell har därför använts för att utvärdera ett antal kombinationer av samplingsstrategi och funktionsyta. Den mest lovande kombinationen har sedan även utvärderats med Regent/VisumDUE. För att vara praktiskt tillämpbart i framtiden har fokus i projektet varit att utvärdera hur metodansatsen fungerar när antalet möjliga tulluppsättningar är kraftigt begränsat (20-40 stycken).Det scenario som har använts som grund i projektet är trängselskatt i Stockholm på nuvarande tullring, på Essingeleden samt på innerstadsbroarna. Skatten är differentierad med avseende på riktning, vilket ger sex olika skattenivåer att optimera. Optimeringen har gjorts för trängselskattenivå under maxtimmen. I det dynamiska fallet har trängselskattens nivå utanför maxtimme funnits med som indata, men samma tidsprofil som på nuvarande tullring har antagits i alla scenarier (avgiftstrappa 50%, 75%, 100%, 75%, 50%). Utvärderingen med den statiska transportmodellen visar att lösningar nära globalt optimum kan uppnås med endast 40 utvärderade trängselskattenivåer, och en tydlig förbättring av den samhällsekonomiska nyttan uppnås redan vid 20 utvärderade trängselskattenivåer.Även med ett kraftigt begränsat antal utvärderingar av den kostsamma målfunktionen i Regent/VisumDUE, har vi visat att det är möjligt att använda metodansatsen. En tydlig förbättring av den samhällsekonomiska nyttan uppnås med endast 22 utvärderade trängselskattenivåer. Ytterligare experiment skulle dock behövas för att undersöka hur stor denna förbättring är i förhållande till vad som skulle kunna uppnås.
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| 16. |
- Eliasson, Jonas, 1969-, et al.
(författare)
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Flexibel trängselskatt ger flyt åt Stockholmstrafiken
- 2012
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Ingår i: Dagens nyheter. - : AB Dagens nyheter. - 1101-2447.
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Omstridd skatt fyller sex. Trängselskattens påverkan på trafiken är till och med större i dag än när den infördes. Att många ändå upplever att köerna blivit längre beror på flera stora byggprojekt som påverkar kapaciteten på vägarna. Trängselskatten bör därför bli mer flexibel och anpassas efter vägarbeten, årstider etc. Essingeleden bör också snarast avgiftsbeläggas. Det skulle enkelt minska trafiken där med 13 procent och göra Stockholm effektivare, renare och trevligare, skriver fyra transportforskare.
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| 17. |
- Engholm, Albin, 1991-, et al.
(författare)
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Cost Analysis of Driverless Truck Operations
- 2020
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Ingår i: Transportation Research Record. - : SAGE Publications. - 0361-1981 .- 2169-4052.
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Tidskriftsartikel (refereegranskat)abstract
- Road freight transport is believed by many to be the first transport domain in which driverless (DL) vehicles will have a significant impact. However, in current literature almost no attention has been given to how the diffusion of DL trucks might occur and how it might affect the transport system. To make predictions on the market uptake and to model impacts of DL truck deployment, valid cost estimates of DL truck operations are crucial. In this paper, an analysis of costs and cost structures for DL truck operations, including indicative numerical cost estimates, is presented. The total cost of ownership for DL trucks compared with that for manually driven (MD) trucks has been analyzed for four different truck types (16-, 24-, 40-, and 64-ton trucks), for three scenarios reflecting pessimistic, intermediate, and optimistic assumptions on economic impacts of driving automation based on current literature. The results indicate that DL trucks may enable substantial cost savings compared with the MD truck baseline. In the base (intermediate) scenario, costs per 1,000 ton-kilometer decrease by 45%, 37%, 33%, and 29% for 16-, 24-, 40-, and 60-ton trucks, respectively. The findings confirm the established view in the literature that freight transport is a highly attractive area for DL vehicles because of the potential economic benefits.
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| 18. |
- Engholm, Albin, et al.
(författare)
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Exploring many objective robust decision making as a tool for managing uncertainty in transport climate policy design
- 2024
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Ingår i: Sammanställning av referat från Transportforum 2024. - Linköping : Statens väg- och transportforskningsinstitut. ; , s. 97-98
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Uncertainty about the future technological and societal trajectories poses challenges to transport planning and policy evaluation. While tools to manage this deep uncertainty have emerged, these have only been integrated into transport applications to a limited extent. This study explores Many Objective Robust Decision Making (MORDM) as a tool for incorporating robustness considerations into the design and assessment of transport climate policies. We demonstrate the MORDM method using a climate policy assessment tool developed by Trafikverket, denoted the scenario tool, and identify challenges and opportunities of MORDM in this context.MORDM is a framework for identifying robust policies given a set of policy levers, uncertain scenario and model parameters, and multiple objectives. First, multi-objective optimization is utilized to generate Pareto-optimal policy candidates in a reference scenario. Thereafter, the robustness and vulnerabilities of candidate policies are assessed by analysis across a large set of scenarios. In this study, we use the open-source Python library EMA workbench to apply MORDM to the scenario tool and perform an example analysis.Decision-making tools for deep uncertainty, like MORDM, have the potential to improve transport planning and policy making. Multi-objective optimization facilitates a systematic identification of a diverse set of Pareto-optimal policies, which can help policymakers to analyze a broad policy spectrum. MORDM also supports comprehensive evaluation of policy robustness against uncertainty. The implementation study highlights the need for making subjective choices in performance and robustness evaluations over multiple objectives. Consequently, active involvement from policy makers throughout the process is crucial. Further research is required on the technical feasibility of applying these tools to more detailed transport and impact assessment models. Additionally, it is important to study how coupling these tools with simple models can support transport planning and policy analysis.
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| 19. |
- Engholm, Albin, 1991-, et al.
(författare)
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Impacts of large-scale driverless truck adoption on the freight transport system
- 2021
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Ingår i: Transportation Research Part A. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0965-8564 .- 1879-2375. ; 154, s. 227-254
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents an analysis of the potential impacts of large-scale adoption of driverless trucks on transport patterns and system costs for a national freight transport system with Sweden as a case study. The analysis is performed by extending the application domain of the Swedish national freight transport model Samgods to analyze two types of driverless truck scenarios. The first scenario represents a full adoption of driverless trucks that can operate the complete road network and thereby substitute manually driven trucks. In this scenario, road transport tonne-kilometers on Swedish territory increase by 22%, vehicle kilometers traveled by trucks increase by 35% and annual total system costs decrease by 1.7 B(sic) compared to a baseline scenario without driverless trucks. In the second scenario, the current fleet of manually driven trucks is complemented by driverless trucks that can operate on major roads between logistics hubs, but not in complex traffic environments like urban areas due to a limited operational design domain. This may be an initial use-case for driverless trucks operating on public roads. In this scenario, road tonne-kilometers increase by 11%, truck vehicle kilometers traveled increase by 15%, and annual total system costs decrease by 1.2 B_ compared to the baseline. For both scenarios, the impacts of driverless trucks vary significantly between commodity types and transport distances which suggests heterogeneity of benefits of automated driving between different types of freight flows. A sensitivity analysis is performed in which the costs for driverless truck operations is varied, and for the second scenario, also which parts of the road network that driverless trucks can operate are varied. This analysis indicates that the magnitude of impacts is highly dependent on the cost level of driverless trucks and that the ability for DL-trucks to perform international, cross-border transport is crucial for achieving reductions in system costs. An overarching conclusion of the study is that driverless trucks may lead to a significant increase in road transport demand due to modal shifts from rail and sea as a result of the improved cost performance of road transport. This would further strengthen the need to decarbonize road transport to meet non-negotiable climate targets. Important topics for future research include assessing potential societal costs related to driverless trucks due to infrastructure investments and negative externalities such as increasing CO2 emissions and congestion.
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| 20. |
- Engholm, Albin, 1991-, et al.
(författare)
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Is the driverless future sustainable? : Strategic uncertainties and system impacts
- 2019
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Konferensbidrag (refereegranskat)abstract
- Future sustainability impacts of driverless vehicles are subject to significant uncertainty which arise from complex systemic interactions within the transportation system and parallel social trends influencing transportation. One approach used to holistically address impacts of driverless vehicles is societal scenarios which capture and problematize the complex interactions. However, they are speculative in their nature and sensitive to the pre-conceptions and knowledge of the experts developing the scenarios. In this paper, multiple scenarios developed in several different studies are compared to create a deeper and broader understanding of system impacts of driverless vehicles and the future society with driverless vehicles than what is achieved through individual scenario studies. The findings show that there are four strategic uncertainties shaping the development: the role of the public and private sector, policy making for driverless vehicles, the impact of the sharing economy and the pace of driverless technology development. Most of the studied scenarios report higher traffic volumes than today. Impacts on social equity and the role of public transport vary significantly between the scenarios. Furthermore, the scenario studies expect the sharing economy to be an enabler to curb growth in travel volumes which is important if climate goals for transportation should be possible to meet. Further research efforts should address impacts of driverless vehicles in more systematic forms than societal scenarios but with wider system delimitations than in existing simulation studies.
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| 21. |
- Engholm, Albin, 1991-, et al.
(författare)
-
MUST Managing Deep Uncertainty in Planning for Sustainable Transport : Project report: phase 1
- 2024
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- There is a growing recognition that traditional forecasting and decision-making approaches might fall short considering the many uncertainties and complexities facing the development of the transport system. The project Managing deep Uncertainty in planning for Sustainable Transport (MUST), funded by Trafikverket and conducted by KTH ITRL and VTI, aims to explore emerging methods for improving the handling of deep uncertainty in the long-term planning of future transport systems. The core of MUST is to explore, develop, and demonstrate tools and methods grounded in Decision Making under Deep Uncertainty (DMDU) and Exploratory Modeling and Analysis (EMA). These approaches are intended to support a shift towards more robust and adaptable planning methodologies.The project is performed in two phases, with the first phase dedicated to laying a foundational understanding of deep uncertainty in transport planning. This report covers the first phase which has included the following tasks: A literature review on deep uncertainty and existing decision-making and system analysis methods under such conditions, with a focus on transportation. A workshop series with Trafikverket identifying transport planning challenges marked by deep uncertainty.A case study of applying DMDU through a case study on climate policy robustness (primarily reported in other deliverables).The literature review covers how the nature of uncertainty in socio-technical systems can be understood, classified, and analyzed. For policy analysis and decision making, the literature underscores the importance of considering multiple futures in model-based analysis when faced with deep uncertainties. DMDU and EMA methods are reviewed and summarized, and their application to transport are discussed. The literature also summarizes studies on uncertainty in model-based transport planning and policy analysis and concludes that the primary location of deep uncertainty is in the model inputs in the form of “scenario uncertainty”. In the workshop series, uncertainty related to producing the base forecast (Swe: basprognos) and policy analysis for domestic transport climate policy was analyzed. This analysis suggested that scenario uncertainty is a main source of deep uncertainty, but also uncertainty related to the system boundaries where highlighted. Furthermore, potential benefits and drawbacks of EMA and DMDU were discussed. In the case study, it is explored how the Scenario tool can be further leveraged by DMDU. More specifically, MORDM (see Section 2.2.3) is applied to assess to what extent it may allow a broader set of policy options to be explored, and how it can provide a better understanding of the robustness and vulnerabilities of different types of policies. A key takeaway from MUST phase 1 is that DMDU and EMA could provide several potential benefits and that methods and tools for applying them are maturing. However, it is possibly a long way to go before DMDU and EMA can be integrated as a regularly used method during the planning process. This is due to organization and process-related issues, as well as technical issues on how to effectively apply DMDU and EMA to Trafikverket’s national transport models. These technical issues will partly be explored in MUST phase 2.
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| 22. |
- Engholm, Albin, 1991-, et al.
(författare)
-
The emerging technological innovation system of driverless trucks
- 2020
-
Ingår i: Transportation Research Procedia. - : Elsevier BV. - 2352-1465. ; , s. 145-149
-
Konferensbidrag (refereegranskat)abstract
- Driving automation technology is attractive for the road freight transport sector since driverless trucks (DL-trucks) may drastically reduce driver costs, increase truck utilization and improve road safety. Although DL-trucks may bring significant impacts to the transport system, research on the future diffusion and impacts of DL-trucks is scarce compared to passenger transport. In this paper the sociotechnical innovation system developing, diffusing and utilizing DL-trucks in Sweden is analyzed based on the technological innovation systems (TIS) framework. The analysis is based on 20 expert interviews with a total of 23 representatives from 16 actors in the DL-truck TIS in Sweden. The TIS analysis shows that there are significant uncertainties in the timeline, operational capabilities, infrastructure requirements and regulative landscape for a widespread DL-truck deployment. There is a general view among the interviewees that DL-trucks is an important opportunity for Swedish industry and the economy. From a transport system perspective, DL-trucks are expected to bring sustainability benefits but it remains uncertain whether these benefits will be realized and what the negative side effects might be. The development of DL-trucks is heavily influenced by incumbent firms in the truck manufacturing industry but new actors from the telecom sector, energy sector and emerging truck technology companies are entering the area and shaping the development. The current relatively rigid institutions for truck manufacturing and road freight transport will require significant alignment to adapt to DL-truck operations in areas such as laws and regulations, business models and operational practices. The value chain of road freight transport may be disrupted as some of the current key actors, for instance traditional road carriers, could become less relevant in future DL-truck value chains. A critical uncertainty is how and by which actors the setting of requirements, deployment and financing of digital infrastructure for DL-trucks will be done.
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| 23. |
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| 24. |
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| 25. |
- Kristoffersson, Ida, 1980-, et al.
(författare)
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A dynamic transportation model for the Stockholm area : Implementation issues regarding departure time choice and OD-pair reduction
- 2009
-
Ingår i: Networks and Spatial Economics. - : Springer Science and Business Media LLC. - 1566-113X .- 1572-9427. ; 9:4, s. 551-573
-
Tidskriftsartikel (refereegranskat)abstract
- Road traffic congestion is an increasing problem in urban areas. Building new roads often attracts latent demand and turns parts of the city into building sites for several years. Policy measures that stimulate more effective use of the existing network, such as variable road pricing, are therefore becoming increasingly popular among policy makers and citizens. These measures are often aimed at changing the temporal distribution of traffic. Yet transportation models taking departure time choice into account are rare. This paper describes the implementation of an urban transportation application for Stockholm, which includes departure time choice, mode choice and time dependent network assignment. Through iterations between demand and supply the objective of the transportation model is to forecast effects of congestion charges, intelligent transport systems and infrastructure investments on departure time choice. The complexity of large-scale departure time choice modelling and dynamic traffic assignment is high, which results in very long run times. Therefore, research on how to increase model efficiency is needed. This paper describes choices made in the implementation for a more efficient model.
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| 26. |
- Kristoffersson, Ida, 1980-, et al.
(författare)
-
Anslutningsresande i långväga prognosmodeller
- 2020
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Sampers är det nationella modellsystemet för att analysera persontransporter i Sverige och används vid trafikslagsövergripande analyser (Trafikverket 2018). Sampers består av två hittills separata modeller – en för regionala resor och en för långväga resor över 100 km. Regionala och långväga modellerna har olika ingående färdmedel (cykel och gång finns inte i långväga och flyg finns inte i regionala modellen), olika zonsystem, olika ingående ärenden etcetera. Att på detta sätt ta fram separata modeller för regionala och långväga resor är vanligt och görs t. ex. även i Norge och Storbritannien. Geografiskt mindre länder så som Nederländerna och Danmark analyserar regionala och långväga resor i samma modell, men behöver då ta särskild hänsyn till skalningseffekter (Rich and Hansen 2016). I modeller så som Sampers där resor delas in i två segment – regionala och långväga – kommer frågan upp hur anslutningsresor till långväga resor bör hanteras.Att få en bättre modellering av anslutningsresande i Sampers vore önskvärt av flera anledningar. Efter en bakgrund och motivering till varför bättre modellering av anslutningsresande behövs, fortsätter rapporten genom att i Kapitel 2 beskriva rapportens syfte. Kapitel 3 ger sedan en beskrivning av den typologi som vi utvecklat för klassificering av anslutningsrese-modeller. I Kapitel 4 redovisas resultaten från genomförd litteratursökning och Kapitel 5 avslutar med att diskutera lärdomar och överväganden inför vidareutveckling av Sampers långväga modell.
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| 27. |
- Kristoffersson, Ida, 1980-, et al.
(författare)
-
Demopan-2 – att kombinera enkätdata och mobilnätsdata för bättre skattning av färdmedelsvalmodell för långväga resor : populärvetenskaplig sammanfattning
- 2023
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Denna rapport beskriver arbetet i projektet Demopan-2 med att utveckla prognosmodeller för färdmedelsval för långväga resor givet att resvaneundersökningar har sjunkande svarsfrekvenser, medan mobilnätsdata framkommit som en potentiell datakälla för resebeteende. I Demopan-1 skattade vi färdmedelsvalsmodeller med mobilnätsdata som enda källa till data om resebeteende. Vi såg då problem i skattningen av modeller på mobilnätsdata. Det ena problemet uppstår på grund av att mobilnätsdata inte innehåller information om ärende (till exempel om resan är en privat resa eller en tjänsteresa). Det andra problemet för att det är svårt att särskilja bil och buss genom automatisk identifikation av färdmedel eftersom de båda använder väginfrastrukturen. I Demopan-2 kombinerar vi mobilnätsdata med enkätdata, för att lösa dessa problem. Genom att genomföra en litteraturöversikt över maskininlärnings-metoder (ML-metoder) och deras tillämpning på färdmedelsval undersöker vi också potentialen för helt nya typer av modeller som skulle kunna ersätta den klassiska logit-modellen.
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| 28. |
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| 29. |
- Kristoffersson, Ida, 1980-, et al.
(författare)
-
Efficiency vs equity : Conflicting objectives of congestion charges
- 2017
-
Ingår i: Transport Policy. - : Elsevier Ltd. - 0967-070X .- 1879-310X. ; 60, s. 99-107
-
Tidskriftsartikel (refereegranskat)abstract
- This paper analyses the trade-off between equity and efficiency in the design of the Stockholm congestion charging systems. Comparing different designs for Stockholm, the paper shows that the most efficient system is the least equitable. Indeed, we show that moving towards a more efficient system design favours high-income-users most. The reason is the uneven distribution of workplaces and residential areas, combined with richer socio-economic groups living in areas with more workplaces. Hence, the conflict between efficiency and equity of this policy arises from the spatial mismatch of residential areas and locations of employment, and the spatial separation between low-income and high-income groups that characterise most cities. This paper shows that these spatial patterns have a large effect on the distribution effects of the congestion charges and that the system design can have a major impact on equity.
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| 30. |
- Kristoffersson, Ida, 1980-, et al.
(författare)
-
Estimating preferred departure times of road users in a real-life network
- 2008
-
Ingår i: Proceedings of the European Transport Conference 2008.
-
Konferensbidrag (refereegranskat)abstract
- The demand for travel continues to increase in European cities of today, which results in long car travel times and highly congested road networks, especially during the morning and afternoon peak periods. The congested car system gives rise to high emissions of particles and greenhouse-gases, which is negative for both the local and global environment. Congestion also causes an uncertain travel time, something that in the latest years has been recognised as a major factor in car-users perception of trip disutility. Congestion is time-dependent in nature. Therefore, not only the spatial distribution of trips over the network is important in analysis and prediction, but also the temporal distribution of trips. A traditional congestion-relieving strategy such as a capacity expansion often has an impact on when people travel, since shorter travel times during the peak hour can attract traffic from the peak shoulders. The temporal effects are even more pronounced for the new policy measures gaining ground today, e.g. variable road pricing. Most variable road pricing systems aim at moving traffic from the peak hour to the peak shoulders, so called peak spreading. The means by which this is done is by charge differentiation: it is most expensive to travel at the most congested point in time. However, most large-scale transport planning models in use today are static and changes in the temporal distribution of trips are not considered. It is therefore likely that false conclusions are drawn when using these models to evaluate the ability of different pricing schemes or infrastructure investments to alleviate congestion.SILVESTER – A Dynamic Transport ModelTo better model the temporal distribution of traffic has been the basis in the development of SILVESTER (SImuLation of choice betWEen Sarting TimEs and Routes), which is a dynamic transport model for the Stockholm area. In SILVESTER road network conditions during the extended morning peak period (06:30-09:30) are modelled. The morning is divided into twelve 15-minute time intervals and a departure time choice model allocates trips to each interval depending on their attractiveness. The attractiveness of a time interval is determined by its corresponding travel time, travel time uncertainty, monetary cost and how close it is to the preferred time interval (PDT) of the traveller. The travellers can also choose to start before 06:30 or after 09:30. Mode choice is partially modelled by introducing the possibility for car-users to switch to public transport if it is perceived as a better option than any of the time intervals. It is distinguished between three trip purposes: business trips, trips with fixed schedule and school trips, and trips with flexible schedule and other trips. In SILVESTER iteration towards a general equilibrium between supply and demand is performed. The supply quantities (travel times, uncertainties etc.) are calculated with the mesoscopic dynamic traffic assignment model CONTRAM, whereas the demand for each time interval and public transport alternative is calculated with a mixed logit discrete choice model. A calibrated origin-destination-matrix (OD-matrix) for the Stockholm CONTRAM network exists and is based mainly on traffic counts but also on travel times for some selected OD-pairs. Calibration of Preferred Departure TimesEven though many trip-timing models use the concept of schedule delay, which is defined as the deviation from a preferred departure/arrival time, little work has been done on how to find the PDT-distribution when applying the model. For estimation the survey respondents can be asked to state their preferred time of travel, but for large-scale applications similar studies are expensive and time consuming. Previous work has often assumed a simplified distribution, such as all travellers in a market segment having the same PDT. Without calibration of PDT’s, e.g. using only a simplified exogenous assumption, the predictive capability of the transport model is questionable. Instead of making an exogenous assumption about the PDT-distribution this paper uses a reverse engineering approach to reveal PDT’s from the observed departure times of the reference situation. It is the combination of the estimated departure time choice model, the travel conditions and the observed departure times that can be used to get information about the PDT’s. Once the PDT’s have been calibrated for the reference situation they can be used in the evaluation of a congestion relieving strategy. This paper will present calibration methodology, obstacles overcome on the way and calibration results. It will also discuss future work in which the calibrated departure time choice model will be used to improve the design (charge levels and time periods) of a pricing scheme.
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| 31. |
- Kristoffersson, Ida, 1980-, et al.
(författare)
-
Estimation of a large-scale tour generation model taking travellers’ daily tour patterns into account
- 2020
-
Ingår i: Transportation planning and technology (Print). - : Routledge. - 0308-1060 .- 1029-0354. ; 43:2, s. 158-173
-
Tidskriftsartikel (refereegranskat)abstract
- Tour generation is conventionally modelled separately according to tour purpose. Tours with different purposes are, however, in reality not generated independently of each other. For example, few travellers conduct more than three tours per day. In this paper, the conventional tour generation model is extended into estimation of a model that takes travellers’ daily tour patterns into account. Results show that access to a car and a drivers’ licence, having a job and presence of children in the household increase the probability of making many tours in one day. Furthermore, results show that accessibility is an important factor for the generation of non-mandatory tours, that weekends and holiday seasons are important determinants of when tour purposes are generated, that high income increases the probability of conducting business tours as well as tour patterns that include expensive activities, and that high income reduces the probability of conducting inexpensive activities such as visiting friends and family. © 2020, © 2020 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.
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| 32. |
- Kristoffersson, Ida, 1980-, et al.
(författare)
-
Estimation of large-scale tour generation model taking travellers' daily tour pattern into account
- 2019
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Tour generation is conventionally modelled separately per tour purpose. Tours with different purposes are however not generated independently of each other in reality. For example, few travellers conduct more than three tours per day. In this paper, the conventional tour generation model is extended into estimation of a model that takes travellers’ daily tour pattern into account. Results show that access to car and drivers’ licence, having a job and presence of children in the household increase the probability of making many tours in one day. Furthermore, results show that accessibility is an important factor for generation of non-mandatory tours, that weekend and holiday season are important determinants of when tour purposes are generated, that high income increases the probability of conducting business tours as well as tour patterns that include expensive activities and that high income reduces the probability of conducting cheap activities such as visiting friends and family.
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| 33. |
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| 34. |
- Kristoffersson, Ida, 1980-, et al.
(författare)
-
Framtidsscenarier för självkörande fordon på väg : samhällseffekter 2030 med utblick mot 2050
- 2017
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Utvecklingen inom tekniken för självkörande fordon går snabbt och många fordonstillverkare (GM, Ford, Toyota, BMW, Audi, VW med flera) anger att de kommer lansera ett fullt ut självkörande fordon på marknaden kring år 2020. Även om teknikutvecklingen har gått och kommer gå snabbt de närmaste åren finns stora frågetecken kvar kring hur de självkörande fordonen kommer tas emot av samhället, var de kommer få köra, om de kommer användas främst som privata eller delade fordon, hur trafik-, integritets- och cyber-säkra de kommer vara och upplevas som av användarna, och i vilken utsträckning de kommer påverka accepterad pendlingstid, färdmedelsval och inducerat bilresande.Samtidigt påverkas de långsiktiga samhällsnyttorna med självkörande fordon inte främst av teknologiska framsteg utan mestadels av vilken roll de självkörande fordonen kommer få i vårt samhälle, det vill säga vilka effekter de får på trafiksystemet och samhällsplaneringen i stort. Det är därför viktigt att tidigt uppskatta möjliga framtidsscenarier för självkörande fordon. Utifrån dessa scenarier kan man sedan föra en diskussion kring hur regler och styrmedel bör användas för att största möjliga samhällsnytta ska uppnås.Detta notat beskriver det arbete med framtidsscenarier för självkörande fordon som gjorts under vintern 2016/2017. En analysgrupp på fem personer har, med stöd av en expertgrupp för persontransporter som samlats för tre heldagsworkshops, arbetat fram både en säker utveckling mot 2030 och två osäkra axlar som lett fram till fyra möjliga scenarier för framtiden med självkörande fordon i Sverige. Med medverkan från 40 experter från 23 organisationer inom transportområdet är denna studie unik jämfört med tidigare scenario-arbeten kring utvecklingen för självkörande fordon, vilka byggt antingen på litteraturstudier eller expertworkshops med ett fåtal forskare.
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| 35. |
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| 36. |
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| 37. |
- Kristoffersson, Ida, 1980-
(författare)
-
Impacts of time-varying cordon pricing : Validation and application of mesoscopic model for Stockholm
- 2013
-
Ingår i: Transport Policy. - : Elsevier BV. - 0967-070X .- 1879-310X. ; 28, s. 51-60
-
Tidskriftsartikel (refereegranskat)abstract
- This paper uses a simulation model to compare traffic and welfare effects of changes to the charging schedule currently in use in Stockholm. In particular, a step toll is compared to its flat counterpart at two charging levels. The increments between steps are also increased in a peaked step toll scenario. Furthermore, results from simulation of the current toll ring are compared to real-world measurements in a first attempt to validate model predictions regarding impacts of a time-varying congestion charging scheme. In the model, car users have the possibility to respond to congestion charging by changing departure time, route or switch to public transport and travel times are calculated using mesoscopic traffic simulation. Validation shows that departure time choice adjustments because of congestion charging are overestimated by the model that is based on stated preference data. This warrants further research on discrepancies between stated and revealed adjustments to congestion charging.The current step toll reaches the highest social benefit estimate in model predictions, but differences in traffic effects between the current step toll and its flat counterpart are rather small. Furthermore, results show that demand changes occur in the model to a considerably greater extent for trips with low value of time. The differences in welfare effects is for that reason large for different trip purposes, indicating the importance of accounting for heterogeneous trips when modelling effects of congestion charges
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| 38. |
- Kristoffersson, Ida, 1980-
(författare)
-
Incorporation of Departure Time Choice in a Mesoscopic Transportation Model for Stockholm
- 2009
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Travel demand management policies such as congestion charges encourage car-users to change among other things route, mode and departure time. Departure time may be especially affected by time-varying charges, since car-users can avoid high peak hour charges by travelling earlier or later, so called peak spreading effects. Conventional transport models do not include departure time choice as a response. For evaluation of time-varying congestion charges departure time choice is essential.In this thesis a transport model called SILVESTER is implemented for Stockholm. It includes departure time, mode and route choice. Morning trips, commuting as well as other trips, are modelled and time is discretized into fifteen-minute time periods. This way peak spreading effects can be analysed. The implementation is made around an existing route choice model called CONTRAM, for which a Stockholm network already exists. The CONTRAM network has been in use for a long time in Stockholm and an origin-destination matrix calibrated against local traffic counts and travel times guarantee local credibility. On the demand side, an earlier developed departure time and mode choice model of mixed logit type is used. It was estimated on CONTRAM travel times to be consistent with the route choice model. The behavioural response under time-varying congestion charges was estimated from a hypothetical study conducted in Stockholm.Paper I describes the implementation of SILVESTER. The paper shows model structure, how model run time was reduced and tests of convergence. As regards run time, a 75% cut down was achieved by reducing the number of origin-destination pairs while not changing travel time and distance distributions too much.In Paper II car-users underlying preferred departure times are derived using a method called reverse engineering. This method derives preferred departure times that reproduce as well as possible the observed travel pattern of the base year. Reverse engineering has previously only been used on small example road networks. Paper II shows that application of reverse engineering to a real-life road network is possible and gives reasonable results.
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| 39. |
- Kristoffersson, Ida, 1980-
(författare)
-
Indikatorer för ökad punktlighet på järnväg : slutrapport inom projektet Nypunkt
- 2019
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Punktlighet är en mycket viktig fråga för järnvägen för att öka passagerares och transportköpares nöjdhet och för att järnvägen ska vara ett konkurrenskraftigt färdmedel i förhållande till andra transportsätt. Att uppnå hög punktlighet är emellertid en komplex uppgift som innefattar samarbete mellan olika organisationer så som infrastrukturförvaltare och tågoperatörer. Ett sådant samarbete har byggts upp i Sverige och kallas TTT (Tillsammans för tåg i tid). TTT har delat upp arbetet för ökad punktlighet i åtta så kallade effektområden: Infrastruktur, Fordon, Obehöriga i spår, Trafik- och resursplanering, Operativ trafikering, Banarbete, Avgångstid och noder, och Från utland. I denna rapport genomförs en analys av arbetet i TTT vilken identifierar synergier mellan effektområdena samt rapporterar om aktuell status för punktlighetsarbetet inom varje effektområde. Vidare har tolv huvudindikatorer för förbättrad järnvägspunktlighet valts ut i denna rapport. Syftet med dessa indikatorer är att hjälpa TTT att analysera och förbättra punktlighetsarbetet. De utvalda indikatorerna täcker både de viktigaste frågorna från effektområdena och aspekter av särskild vikt för resenärer, såsom mycket långa förseningar och inställda tåg.
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| 40. |
- Kristoffersson, Ida, 1980-, et al.
(författare)
-
Modelling connection trips to long-distance travel : state-of-the-art and directions for future research
- 2020
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Connection trips is often an important part of long-distance travel, especially for air travel. Models of long-distance travel would therefore benefit from a more detailed representation of the connection part. In this paper it is however shown that most models of connection trips are stand-alone models not integrated with the model for main mode. A handful models that integrate connection trip modelling into a large-scale transport model for long-distance travel are found and classified into different types using a typology developed within the paper. The scarce literature on connection trip modelling within large-scale systems call for more research regarding detailed representation of access/egress mode choice and terminal choice, especially regarding the trade-off between model complexity and detailed representation.
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| 41. |
- Kristoffersson, Ida, 1980-, et al.
(författare)
-
Modelling connection trips to long-distance travel
- 2022
-
Ingår i: European Transport Research Review. - : SPRINGER. - 1867-0717 .- 1866-8887. ; 14:1
-
Forskningsöversikt (refereegranskat)abstract
- Connection trips is often an important part of long-distance travel, especially for air travel. Models of long-distance travel would therefore benefit from a more detailed representation of the connection part. In this paper it is however shown that most models of connection trips are stand-alone models not integrated with the model for main mode. Only a handful models that integrate connection trip modelling into a large-scale transport model for long-distance travel are found. The connection trip models are classified into different types using a typology developed within the paper. The typology identifies nine model types that differ in how access/egress mode choice and terminal choice are handled. The scarce literature on connection trip modelling within large-scale transport modelling systems call for more research regarding detailed representation of access/egress mode choice and terminal choice, especially regarding the trade-off between model complexity and detailed representation, as well as whether the detailed representation of connection trips should primarily be conducted within the public transport network assignment or on the demand modelling side.
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| 42. |
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| 43. |
- Kristoffersson, Ida, 1980-, et al.
(författare)
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Modelling the attraction of travel to shopping destinations in large-scale modelling
- 2018
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Ingår i: Transport Policy. - : Elsevier Ltd. - 0967-070X .- 1879-310X. ; 68, s. 52-62
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Tidskriftsartikel (refereegranskat)abstract
- Development of major shopping centres continues even though online shopping is increasing. This has implications for mode and destination choice for shopping travel and therefore also for sustainability, which need to be considered in planning policy. In this paper, we estimate models for shopping travel using an unusually rich data set of shopping attractions. We find that shopping travel is best represented in three separate models: consumables in short and long activity segments and durables. In all of these models, we show that representing nearby attractions outside the destination zone adds to the measured attraction. For long activity consumables and for durables, the addition of secondary attractions within 2 km of the main destination gives the best models. For short activity consumables, both 2 km and 5 km add to the model, but 5 km is slightly better. Furthermore, we find significant within-zone correlation in the consumables models but are unable to find significant between-zone correlation, indicating that zone boundaries have some behavioural meaning for shopping travellers, but larger areas are not viewed in this way. Shopping attractions with a specifically Swedish impact, Systembolaget (official alcohol outlet in Sweden) and IKEA, proved to be important in all the models. These attractors work better as part of the size than as part of the utility, indicating that they appear to be separate attractors of trips, rather than as adding to the utility of other attractors. The models are also applied in two policy scenario analyses in which the impacts of new IKEA establishments and availability of Systembolaget in all zones on destination and mode choice are assessed.
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| 44. |
- Kristoffersson, Ida, 1980-, et al.
(författare)
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Motstånd mot sänkt hastighetsgräns i glesbygd : en djupdykning i avvägningen mellan trafiksäkerhet och tillgänglighet
- 2024
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Ingår i: Sammanställning av referat från Transportforum 2024. - Linköping : Statens väg- och transportforskningsinstitut. ; , s. 24-25
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Med Nollvisionen som utgångspunkt har Trafikverket (TRV) sett över hastighetsgränser på svenska vägar generellt utifrån ett antal principer. En viktig riktlinje har varit att vägar utan mittseparering och med årsmedeldygnstrafik över 2000 fordon/dygn inte får ha en hastighetsgräns över 80 km/h. Anpassningar av hastighetsgränser har pågått länge och effekterna har följts upp på kort och medellång sikt. Senaste hastighetsanpassningarna var planerade att fortsätta till år 2025, men på grund av protester har flera sänkningar av hastighetsgräns skjutits upp. Dessutom har TRV fått ett uppdrag av regeringen att utveckla arbetet medhastighetsanpassningar. Protesterna gäller framför allt sträckor som planerats att sänkas från 100 km/h eller 90 km/h till 80 km/h. De anledningar som anges i remissvar och överklaganden betonar tillgänglighet till och inom glesbefolkade områden med långa avstånd, kopplat till konkurrenskraft och regional utveckling.I denna studie har vi analyserat 77 sträckor där TRV sänkt hastighetsgränsen från 100 km/h eller 90 km/h till 80 km/h under år 2019 och 2020. Genom att skatta en logit-modell för sannolikheten att en sänkt hastighetsgräns på en sträcka kommer överklagas, identifierar vi faktorer som är kopplade till missnöje med den sänkta hastighetsgränsen och karaktäristik hos de kommuner/regioner som har överklagat sänkta hastighetsgränser.Data om sträckorna har hämtats från TRV:s regionala hastighetsanalyser, genomförda som beslutsunderlag före implementering (sträckans längd, uppskattad restidskostnad och trafiksäkerhetsvinst), Nationella vägdatabasen (vägbreddklass, E-väg, nationellt och internationellt viktiga vägar), SCB (befolkningstäthet per kommun) och Tillväxtverket (sårbarhetsindex per kommun). Resultaten visar att sänkt hastighetsgräns är mer sannolik att överklagas för E-vägar, långa sträckor av sänkt hastighetsgräns och i områden där det finns ett universitet, medan sannolikheten minskar med befolkningstäthet och kommunens sårbarhet.
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| 45. |
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| 46. |
- Kristoffersson, Ida, 1980-, et al.
(författare)
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Representing travel cost variation in large-scale models of long-distance passenger transport
- 2020
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In this paper we show that travel cost variation for long-distance travel is often substantial, even within a given mode, and we discuss why it is likely to increase further in the future. Thus, the current praxis in large-scale models to set one single travel cost for a combination of origin, destination, mode, and purpose, has potential for improvement. To tackle this issue, we develop ways of accounting for cost variation in model estimation and forecasting. For public transport, two methods are developed, where the first method focuses on improving the average fare, whereas the second method incorporates a submodel for choice of fare alternative within a demand model structure. Only the second method is consistent with random utility theory. For car, cost variation is related to long run decisions such as car type choice and employment location. Handling car cost variation therefore implies considering car type choice and workplace choice rather than different options related to a specific trip. These long-term choices can be considered using a car fleet model.
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| 47. |
- Kristoffersson, Ida, 1980-, et al.
(författare)
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Representing travel cost variation in large-scale models of long-distance passenger transport
- 2022
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Ingår i: Transportation letters. - : Taylor & Francis. - 1942-7867 .- 1942-7875. ; :7, s. 778-786
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper, we show that cost variation for long-distance travel is often substantial and we discuss why it is likely to increase further in the future. Thus, the current practice in large-scale models, to set one single travel cost for a combination of origin, destination, mode, and purpose, has potential for improvement. To tackle this issue, we develop ways of accounting for cost variation in model estimation and forecasting. For public transport, two approaches are proposed. The first method focusses on improving the average fare, whereas the second approach incorporates a submodel for choice of fare alternative within a demand model structure. Only the second method is consistent with random utility theory. For car, cost variation is related to long run decisions such as car type choice. Handling car cost variation therefore implies considering car type choice. This long-term choice can be considered using a car fleet model. © 2021 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.
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| 48. |
- Kristoffersson, Ida, 1980-, et al.
(författare)
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Sampers4 : Skattning av regionala efterfrågemodeller
- 2018
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Denna rapport har tagits fram som slutrapportering av projektet ”Sampers4 -fortsättning” finansierat av Trafikverket, som genomförts under hösten 2017 och våren 2018. Detta projekt har tagit vid där tidigare omskattningsprojekt för Sampers regionala efterfrågemodeller slutat. De största förändringarna och förbättringarna i denna senaste omskattning är:att även de som inte angivit någon inkomst i RVU har fått en inkomst påkodad,att hushållsvariabler kunnat inkluderas i skattningen på grund av framsteg inom framtagning av syntetisk befolkning med hushållsdata som kan användas vid implementering,att konsistensen mellan utbud och efterfrågan förbättrats genom att impedansen från kollektivtrafikutläggningen använts i skattning av efterfrågemodeller för färdmedelsval.Projektet ”Sampers4 –fortsättning” har avgränsats till att gälla skattning av regionala efterfrågemodeller. Implementering av modellerna har påbörjats i tidigare omskattningsprojekt, men har inte ingått i detta projekt. Vi inser att mycket av vårt arbete i detta projekt inte kunnat göras utan det arbete som gjorts i tidigare omskattningsprojekt.
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| 49. |
- Kristoffersson, Ida, 1980-, et al.
(författare)
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Scenarios for the development of self-driving vehicles in freight transport
- 2018
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Ingår i: <em>Proceedings of 7th Transport Research Arena TRA2018</em>. - : Zenodo.
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Konferensbidrag (refereegranskat)abstract
- This paper extends previous research by developing future scenarios for self-driving vehicles and their societal impacts in freight transport using Sweden as a case study. Freight experts from vehicle manufacturers, agencies, universities and hauliers were recruited for a workshop where they assessed the benefits, costs, possibilities and barriers for self-driving vehicles in freight transport. The paper shows that reduction in driver and vehicle costs, reduced number of incidents and more fuel-efficient driving are seen as the main benefits of self-driving vehicles in freight transport, and increased vehicle costs, lost jobs, reduced degree of filling and more transport as the main costs. Furthermore, reduced drivers’ costs, more hours-of-service and new business models are identified as the main drivers of the development and traffic management, small hauliers, loading and unloading and cross-border transport as the main barriers. The paper also integrates the description of possible developments of self-driving vehicles in freight transport into the four future scenarios developed for passenger transport in Sweden.
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| 50. |
- Kristoffersson, Ida, 1980-, et al.
(författare)
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The Swedish Congestion Charges : Lessons Learnt
- 2018
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Ingår i: Road Pricing. - : IET. - 9781785612060
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Bokkapitel (refereegranskat)abstract
- The charging systems in Sweden show that congestion charges can be an efficient (socio-economically beneficial) and effective policy measure for combating urban congestion. Furthermore, the technology of the Swedish charging systems has proven to work well, with high accuracy of correctly identified vehicles using the video technique with ANPR. The case of Gothenburg demonstrates this measure is not only less efficient if initial congestion levels are low, but also less efficient in the long run: the effects are declining in the long run. In Stockholm, the effects have increased over the years. The difference between the cities in this respect could be a result of the lower density city structure and high car dependence in Gothenburg. From this perspective, congestion charges are likely most successful in cities where congestion levels are high and where there exist good alternatives to driving.
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