| 1. |
- Nåbo, Arne, 1958-, et al.
(författare)
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Regeringsuppdrag om elektrifieringen av transporter : rekommendationer för att underlätta datadelning och nyttiggörande av data för planering, utveckling och drift av laddinfrastruktur och affärsmodeller
- 2023
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Regeringen har uppdragit åt Statens väg- och transportforskningsinstitut (VTI) att ”bidra till kunskapsuppbyggnaden kring en snabb, smart och samhällsekonomiskt effektiv elektrifiering av transportsektorn”. Den här rapporten redovisar den del av uppdraget som handlar om att genomföra pilotprojekt och ta fram modeller för hur data i praktiken på bästa sätt kan tillgängliggöras, delas och nyttiggöras för att optimera planering, utveckling, drift samt affärsmodeller för laddinfrastruktur. I rapporten ges en beskrivning av förekommande tekniker för laddning av elfordon, viktiga användarperspektiv, och hur affärsmodeller och system för laddinfrastruktur kan modelleras. Rapporten fokuserar på datadelning och beskriver hur aktörer idag delar data samt vilka svårigheter de ser med datadelning. Detta omfattar bland annat datatillgänglighet, delning och nyttiggörande, samt hur aktörerna vill att det ska fungera framåt. En stor utmaning handlar om datatillgänglighet, där aktörer dels ser problem med att få tillgång till data och dels är avvaktande till att vilja dela med sig av egna data. Ofta handlar det om integritetsfrågor och reglering enligt GDPR. Betydelsen av en väl fungerande samverkan mellan energi- och transportsektorn har lyfts i tidigare rapporteringar från det här uppdraget. Vikten av en digitalisering och digital infrastruktur som kopplar samman dessa sektorer betonas speciellt i detta arbete. Digitalisering behövs för att effektivisera planering, utveckling och drift av den infrastruktur som ett elektrifierat transportsystem kräver. De modelleringar som gjorts i den här delen av uppdraget handlar om transportmodellering och energimodellering samt utveckling för att få modellerna att samspela.
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| 2. |
- Abenoza, Roberto F., et al.
(författare)
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What is the role of weather, built-environment and accessibility geographical characteristics in influencing travelers’ experience?
- 2019
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Ingår i: Transportation Research Part A. - : Elsevier Ltd. - 0965-8564 .- 1879-2375. ; 122, s. 34-50
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Tidskriftsartikel (refereegranskat)abstract
- We examine the effect of weather, accessibility and built-environment characteristics on overall travel experience as well as the experience with the latest trips. These are factors that are often disregarded in the travel satisfaction literature even though they are believed to largely influence the first mile of the door-to-door trip. This study fills a research gap in investigating all these factors by using, amongst other, a relatively large travel satisfaction survey from years 2009 to 2015 and by focusing on urban and peri-urban geographical contexts, the city and county of Stockholm (Sweden), respectively. The ordered logit model results show that county dwellers living close to a metro station and in well linked-to-all areas report higher overall travel satisfaction evaluations. In addition, precipitation and ground covered with snow have a negative influence on travel satisfaction. Our findings indicate that built-environment characteristics exert a rather weak influence on the travel experience, especially in the peri-urban context. However, some aspects such as living in areas with medium densities, low income and with high safety perceptions around public transport stations are associated with higher satisfaction levels. In turn, areas with single land uses are found to have lower travel satisfactions. These results are important for public transport planners and designers in devising measures to prevent and mitigate the negative outcome of some weather conditions and to conceive better designed transit oriented developments.
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| 3. |
- Böcker, Lars, et al.
(författare)
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Weather and daily mobility in international perspective : A cross-comparison of Dutch, Norwegian and Swedish city regions
- 2019
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Ingår i: Transportation Research Part D. - : Elsevier. - 1361-9209 .- 1879-2340. ; 77, s. 491-505
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Tidskriftsartikel (refereegranskat)abstract
- With climate change, weather has emerged as an important theme in transport research and planning. Although recent studies demonstrate profound weather effects on mobility in single case study areas, international cross-comparisons are required to reveal how effects differ between cities with different transport and climate regimes. This paper provides an international cross-comparison of the simultaneous effects of weather on destination choices, distances, trip chaining, and transport modes in the urban regions of Utrecht (Netherlands), Oslo and Stavanger (Norway), and Stockholm (Sweden). Hereto, regional subsamples of national travel survey data were linked to meteorological records for the three respective countries and analysed in generalised Structural Equation Models. Our findings generally indicate that light, calm, dry and warm atmospheric conditions may positively affect cycling and the selection of outdoor leisure destinations, while cold and to a lesser extent wet and windy weather conditions reduce cycling and enhance car use and travel optimising strategies like trip chaining, to reduce weather exposures. A positive effect of air temperature on cycling flattens out above 20–25 °C in most of our study areas, but hot weather does not seem to reduce cycling strongly. However, our findings also show considerable regional differences in the effects of weather on mobility. Both general effects and differences are interpreted in relation to geographical context, transport and land use, climate conditions, cultures, habits and adaptations and are discussed to formulate policies to mitigate active transport mode users’ exposures to adverse weather and make walking and cycling (even more) year-round modes.
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| 4. |
- Börjesson, Maria, et al.
(författare)
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The impact of optimal rail access charges on frequencies and fares
- 2021
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Ingår i: Economics of Transportation. - : Elsevier. - 2212-0122 .- 2212-0130. ; 26-27
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Tidskriftsartikel (refereegranskat)abstract
- Sweden has been a front runner in vertical separation. We use data from the business long-distance corridor in Sweden to calibrate and define a demand and supply model. We simulate how the profit, welfare, fares, frequencies, modal shares and train size depend on the level of the track charges. We simulate the welfare optimal track charges, given different levels of congestion on the track, hence using the charges as a pricing instrument to allocate the train slots efficiently. We find that increases in charges have a limited impact on fares but larger impacts on the frequency. When the length of the trains can be extended and when the crowding penalty is high, the impact of higher track charges on the frequencies is larger. Higher track charges increase the length of the trains if possible. The intermodal competition from road and air has a significant impact on rail fares.
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| 5. |
- Chen, M., et al.
(författare)
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Service evaluation of public bicycle scheme from a user perspective
- 2017
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Ingår i: Transportation Research Record. - : National Research Council. - 0361-1981 .- 2169-4052. ; 2634, s. 28-34
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Tidskriftsartikel (refereegranskat)abstract
- In late 2005, in an attempt to solve the last-mile problem, China started implementing public bikesharing programs. The effort quickly grew to a massive scale. An estimated 400,000 public bicycles now are in use in China, which is more than in all other countries that have implemented public bicycle schemes (PBSs). As with any emerging service that develops rapidly, an understanding of user behavior and satisfaction is lacking. Factors that influence the frequency of public bicycle use were studied in Hangzhou, China. Online and intercept surveys were conducted with PBS users. Willingness to use the PBS as well as satisfaction with and concerns about the PBS were investigated. Analysis of variance was conducted to identify the six factors that affect a user's decision to rent: car ownership, bicycle ownership, travel purpose, having or lacking familiarity with the rental process, level of satisfaction with the PBS, and level of familiarity with the distribution of docking stations. Binary logistic regression analysis was used to elucidate details of key factors in the group of most frequent users-that is, survey respondents who did not own a car, rented a bicycle primarily for shopping or going out for business, and were familiar with the rental process and the distribution of docking stations. Based on study findings, advice is presented for implementing policy in developing countries. Suggestions include publicizing the PBS more, attracting more commuters to bicycling to reduce congestion, enhancing the accessibility of docking stations to accommodate more potential users, and improving bicycle quality to encourage more participation and make it easier for elderly citizens to participate.
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| 6. |
- Chengxi, Liu, 1987-, et al.
(författare)
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Estimating changes in transport CO2 emissions due to changes in weather and climate in Sweden
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- There is a considerable body of studies on the relationship between daily transport activities and CO2 emissions. However, how these emissions vary in different weather conditions within and between the seasons of the year is largely unknown. Because individual activity–travel patterns are not static but vary in different weather conditions, it is immensely important to understand how CO2 emissions vary due to the change of weather. Using Swedish National Travel Survey data, with emission factors calculated through the European emission factor model ARTEMIS, this study is a first attempt to derive the amount of CO2 emission changes subject to the change of weather conditions. A series of econometric models was used to model travel behaviour variables that are crucial for influencing individual CO2 emissions. The marginal effects of weather variables on travel behaviour variables were derived. The results show an increase of individual CO2 emissions in a warmer climate and in more extreme temperature conditions, whereas increasing precipitation amounts and snow depths show limited effects on individual CO2 emissions. It is worth noting that the change in CO2 emissions in the scenario of a warmer climate and a more extreme temperature tends to be greater than the sum of changes in CO2 emissions in each individual scenario. Given that a warmer climate and more extreme weather could co-occur more frequently in the future, this result suggests even greater individual CO2 emissions than expected in such a future climate.
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| 7. |
- Chengxi, Liu, 1987-, et al.
(författare)
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Jointly modelling individual’s daily activity-travel time use andmode share by a nested multivariate Tobit model system
- 2015
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Ingår i: Transportation Research Procedia. - : Elsevier. - 2352-1465. ; , s. 71-89
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Konferensbidrag (refereegranskat)abstract
- Understanding mechanisms underlie the individual’s daily time allocations is very important to understand the variability ofindividual’s time-space constraints and to forecast his/her daily activity participation. At most of previous studies, activity timeallocation was viewed as allocating a continuous quantity (daily time budget) into multiple discrete alternatives (i.e. variousactivities and trips to engage with). However, few researches considered the influence of travel time that needs to be spent onreaching the activity location. Moreover, travel time itself is influenced by individuals’ mode choice. This can lead to an over- orunder-estimation of particular activity time location. In order to explicitly include the individual’s travel time and mode choiceconsiderations in activity time allocation modelling, in this study, a nested multivariate Tobit model is proposed. This proposedmodel can handle: 1. Corner solution problem (i.e. the present of substantial amount of zero observations); 2. Time allocationtrade-offs among different types of activities (which tends to be ignored in previous studies); 3. Travel is treated as a deriveddemand of activity participation (i.e. travel time and mode share are automatically censored, and are not estimated, ifcorresponding activity duration is censored). The model is applied on a combined dataset of Swedish national travel survey(NTS) and SMHI (Swedish Meteorological and Hydrological Institute) weather record. Individuals’ work and non-work activitydurations, travel time and mode shares are jointly modelled as dependent variables. The influences of time-locationcharacteristics, individual and household socio demographics and weather characteristics on each dependent variable areexamined. The estimation results show a strong work and non-work activity time trade-offs due to the individual’s time-spaceconstraints. Evidences on a potential positive utility of travel time added on non-work activity time allocation in the Swedish case,are also found. Meanwhile, the results also show a consistent mode choice preference for a given individual. The estimatednested multivariate Tobit model provides a superior prediction, in terms of the deviation of the predicted value against the actualvalue conditional on the correct prediction regarding censored and non-censored, compared to mutually independent Tobitmodels. However, the nested multivariate Tobit model does not necessarily have a better prediction for model componentsregarding non-work related activities.
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| 8. |
- Chengxi, Liu, 1987-, et al.
(författare)
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Subjective perception towards uncertainty on weather conditions and its impact on out-of-home leisure activity participation decisions
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Weather is fundamentally a ‘subjective’ perception rather than an objective measure that affects individual’s everyday travel decisions. This study uses data from a four-wave travel diary survey and aims to answer two research questions, i.e. 1. How individuals from different socio-demographic groups perceive weather. 2. How subjective weather perceptions affect individuals’ leisure activity participation decisions. Subjective weather perception and leisure activity participation are modelled in panel static/dynamic ordered Probit models. The results show that the reference thermal environment in general corresponds to the historical mean of the thermal environment. The effects of objective weather measures on subjective weather perception vary substantially between individuals. Moreover, the effect of subjective weather perception on leisure activity participation is non-linear and asymmetric. Only “very bad weather” and “very good weather” significantly influence the leisure activity participation. The effect of “very bad weather” also varies significantly between individuals. The intra-individual heterogeneity in the effect of “very good weather” has a smaller magnitude than that in the effect of “very bad weather”.
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| 9. |
- Chengxi, Liu, 1987-
(författare)
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Understanding the Impacts of Weather and Climate Change on Travel Behaviour
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Human behaviour produces massive greenhouse gas emissions, which trigger climate change and more unpredictable weather conditions. The fluctuation of daily weather corresponds to variations of everyday travel behaviour. This influence, although is less noticeable, can have a strong impact on the transport system. Specifically, the climate in Sweden is becoming warmer in the recent 10 years. However, it is largely unknown to what extent the change of travel behaviour would respond to the changing weather. Understanding these issues would help analysts and policy makers incorporate local weather and climate within our policy design and infrastructure management.The thesis contains eight papers exploring the weather and climate impacts on individual travel behaviour, each addressing a subset of this topic. Paper I explores the weather impact on individual’s mode choice decisions. In paper II and III, individual’s daily activity time, number of trips/trip chains, travel time and mode shares are jointly modelled. The results highlight the importance of modelling activity-travel variables for different trip purposes respectively. Paper IV develops a namely nested multivariate Tobit model to model activity time allocation trade-offs. In paper V, the roles of weather on trip chaining complexity is explored. A thermal index is introduced to better approximate the effects of the thermal environment. In paper VI, the role of subjective weather perception is investigated. Results confirm that individuals with different socio-demographics would have different subjective weather perception even given similar weather conditions. Paper VII derives the marginal effects of weather variables on transport CO2 emissions. The findings show more CO2 emissions due to the warmer climate in the future. Paper VIII summaries the existing findings in relations between weather variability and travel behaviour, and critically assesses the methodological issues in previous studies.
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| 10. |
- Chengxi, Liu, 1987-, et al.
(författare)
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Weather Variability and Travel Behaviour - What Do We Know and What Do We Not Know
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Given that severe weather conditions is becoming more and more frequent, understanding the roles of weathers in influencing individual’s daily activity-travel pattern is important. Whilst some of previously rare events, such as heavy rain, unpredictable snow, higher temperature, less clear differences between seasons etc., would become more common, it is still largely unknown how individual would change and adapt their travel pattern in future climate conditions. Because of this concern, the number of researches on weather and travel behaviour has been increased dramatically in the recent decades. Most of those empirical evidences, however, have not been adopted in cost-benefit analysis (CBA), which serves as the main tool for policy evaluation and project selection by stakeholders. This study summarizes the existing findings in relations between weather variability and travel behaviour, and critically assesses the methodological issues in those studies. Several further research directions are identified and suggested for bridging the gap between empirical evidence and current practice in CBA.
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