Vol 16 No 4 (2016)
2016-09-01
Vol 16 No 4 (2016)
2016-09-01
Articles
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The use of solid biofuel for energy in heating plants has increased drastically during the last decades. This substantial and increasing demand has placed focus on delivering biofuel to the plants, as logistics issues are considered one of the key challenges for further increased use of biofuel. Problems in sourcing enough fuel locally due to the increasing size of power plants and environmental concerns has sparked an interest in using multimodal road-rail transport as a cost effective and environmentally friendly way of long-haul transport. A case study is performed at a Swedish district heating plant to investigate the potential of introducing multimodal transport. Extensive calculations are performed in the design and operation of a multimodal system, showing both costs and CO2 emissions. This is analysed in relation to key logistical challenges in the industry. A best case scenario is identified. Conclusions are that the potential for multimodal transport is greatest among the largest plants with large volumes to achieve high resource utilisation of the transport equipment. A shift from road to multimodal transport is facilitated by that a large share of the current road transport flows already pass through a terminal, which improves multimodal transport competitiveness against road transport as this reduced the cost difference. This study leads to better understanding of the strengths and weaknesses of multimodal biofuel transport and has practical implications for anyone in the process of designing such systems.
The use of solid biofuel for energy in heating plants has increased drastically during the last decades. This substantial and increasing demand has placed focus on delivering biofuel to the plants, as logistics issues are considered one of the key challenges for further increased use of biofuel. Problems in sourcing enough fuel locally due to the increasing size of power plants and environmental concerns has sparked an interest in using multimodal road-rail transport as a cost effective and environmentally friendly way of long-haul transport. A case study is performed at a Swedish district heating plant to investigate the potential of introducing multimodal transport. Extensive calculations are performed in the design and operation of a multimodal system, showing both costs and CO2 emissions. This is analysed in relation to key logistical challenges in the industry. A best case scenario is identified. Conclusions are that the potential for multimodal transport is greatest among...
The use of solid biofuel for energy in heating plants has increased drastically during the last decades. This substantial and increasing demand has placed focus on delivering biofuel to the plants, as logistics issues are considered one of the key challenges for further increased use of...
Jonas Flodén -
Using a dataset with transport choices of the same set of individuals (college students from University of La Laguna), we built a novel three waves panel data around a tramline implementation in the Santa Cruz-La Laguna corridor in Tenerife, Spain. The first two waves were conducted in 2007, just before the tram implementation. They collect information about Revealed Preferences (RP) of actual transport mode choices (car, bus and walk) and about Stated Preferences (SP) in a simulated scenario considering a hypothetical binary choice between the tram and the transport mode currently chosen by the students. The third wave gathers information about RP in 2009, two years after the tram started operating. With this information, we estimate several multinomial logit models and panel mixed logit models with error components. The aim of this paper is to evaluate how the estimation of the Values of Travel Time Savings (VTTS) changes when comparing the results obtained with models that only consider information before or after the tram implementation with that obtained with a panel data approach using the three waves simultaneously (RP/SP in 2007 and RP in 2009). We obtain a better statistical fit to data and, according to our study context, more reasonable VTTS using a panel data approach combining before and after information and both revealed and stated preferences. Our results suggest that when a new transport mode is implemented, the VTTS obtained with models than only consider prior or later periods of time can be underestimated and hence lead to wrong valuations of the benefits associated with the new alternative, even when stated preferences are used to anticipate the change in the transport system.
Using a dataset with transport choices of the same set of individuals (college students from University of La Laguna), we built a novel three waves panel data around a tramline implementation in the Santa Cruz-La Laguna corridor in Tenerife, Spain. The first two waves were conducted in 2007, just before the tram implementation. They collect information about Revealed Preferences (RP) of actual transport mode choices (car, bus and walk) and about Stated Preferences (SP) in a simulated scenario considering a hypothetical binary choice between the tram and the transport mode currently chosen by the students. The third wave gathers information about RP in 2009, two years after the tram started operating. With this information, we estimate several multinomial logit models and panel mixed logit models with error components. The aim of this paper is to evaluate how the estimation of the Values of Travel Time Savings (VTTS) changes when comparing the results obtained with models that...
Using a dataset with transport choices of the same set of individuals (college students from University of La Laguna), we built a novel three waves panel data around a tramline implementation in the Santa Cruz-La Laguna corridor in Tenerife, Spain. The first two waves were conducted in 2007,...
Rosa Marina González, Ángel S. Marrero, Gustavo A. Marrero -
The paper describes the structure of the new Danish National Passenger model and provides on this basis a general discussion of large-scale model design, cost-damping and model validation. The paper aims at providing three main contributions to the existing literature. Firstly, at the general level, the paper provides a description of a large-scale forecast model with a discussion of the linkage between population synthesis, demand and assignment. Secondly, the paper gives specific attention to model specification and in particular choice of functional form and costdamping. Specifically we suggest a family of logarithmic spline functions and illustrate how it is applied in the model. Thirdly and finally, we evaluate model sensitivity and performance by evaluating the distance distribution and elasticities. In the paper we present results where the spline-function is compared with more traditional function types and it is indicated that the spline-function provides a better description of the data. Results are also provided in the form of a back-casting exercise where the model is tested in a back-casting scenario to 2002.
The paper describes the structure of the new Danish National Passenger model and provides on this basis a general discussion of large-scale model design, cost-damping and model validation. The paper aims at providing three main contributions to the existing literature. Firstly, at the general level, the paper provides a description of a large-scale forecast model with a discussion of the linkage between population synthesis, demand and assignment. Secondly, the paper gives specific attention to model specification and in particular choice of functional form and costdamping. Specifically we suggest a family of logarithmic spline functions and illustrate how it is applied in the model. Thirdly and finally, we evaluate model sensitivity and performance by evaluating the distance distribution and elasticities. In the paper we present results where the spline-function is compared with more traditional function types and it is indicated that the spline-function provides a better...
The paper describes the structure of the new Danish National Passenger model and provides on this basis a general discussion of large-scale model design, cost-damping and model validation. The paper aims at providing three main contributions to the existing literature. Firstly, at the general...
Jeppe Rich, Christian Overgaard Hansen -
A review of the body of literature yields general indications that electric freight vehicles can improve emissions and costs in off-hour delivery schemes. However, the literature fails to quantify the savings potential in a combined day and off-hours double-shift usage. Hence, this article qualitatively clusters the advantages of electric vehicles in off-hours delivery schemes and provides quantitative exemplary model calculations on the total costs of ownership in single- and double- shift usage. Surprisingly, the calculations contradict the hypothesis that is commonly deduced in the literature that with a higher utilisation, electric vehicles generally become more competitive compared to their conventional siblings. This study finds that electric medium-duty vehicles are only financially competitive at higher mileages, if the savings achieved by lower operational costs are greater than the costs for battery replacements. These become more frequent at higher mileages; hence a long battery warranty is essential when planning to operate EVs in double-shifts. An elasticity analysis finds that further important parameters influencing the competitiveness of medium-duty electric vehicle compared to conventional diesel models are the discount rate, purchase prices, and the cost of diesel fuel. In conclusion, financial subsidies for purchasing freight EVs might lead to higher numbers of these vehicles. However, increasing the per-kilometre cost advantage of electric freight vehicles would support their utilisation, i.e. in combined day and night shifts, and hence would further mitigate the road freight transport emissions in cities.
A review of the body of literature yields general indications that electric freight vehicles can improve emissions and costs in off-hour delivery schemes. However, the literature fails to quantify the savings potential in a combined day and off-hours double-shift usage. Hence, this article qualitatively clusters the advantages of electric vehicles in off-hours delivery schemes and provides quantitative exemplary model calculations on the total costs of ownership in single- and double- shift usage. Surprisingly, the calculations contradict the hypothesis that is commonly deduced in the literature that with a higher utilisation, electric vehicles generally become more competitive compared to their conventional siblings. This study finds that electric medium-duty vehicles are only financially competitive at higher mileages, if the savings achieved by lower operational costs are greater than the costs for battery replacements. These become more frequent at higher mileages; hence a...
A review of the body of literature yields general indications that electric freight vehicles can improve emissions and costs in off-hour delivery schemes. However, the literature fails to quantify the savings potential in a combined day and off-hours double-shift usage. Hence, this article...
Tessa T. Taefi -
The purpose of the paper is to analyze model uncertainty and economies of scale of the Swedish national freight transport model system Samgods to changes in its zone-to-zone base matrices. Even though economies of scale is important for freight transport, few studies analyze model uncertainty and economies of scale at a national level. Compared to many large scale networkbased freight models working on aggregated transport flows, an important feature in Samgods is that it simulates logistics behavior at a disaggregated firm level. The paper studies effects on total tonne- and vehicle-kilometre, modal split, consolidation and logistics costs when the base matrices are scaled up and down and estimates economies of scale for Swedish freight transports. The results indicate that the logistics model can find new logistics solutions for larger demand volumes, mainly by shifting freight to sea transport. If transport volume increases with one percent, average logistics cost per tonne is reduced by around 0.5 percent. Part of the cost reduction comes from increased consolidation of shipments due to larger transport volumes. The results derived in the paper can serve as a reference for empirical validation and comparisons with other large scale freight models. The paper is a first contribution that tries to fill the knowledge gap on the impact of base matrices on transport model outcomes, such as economies of scale, in the context of a full-fledged real-world freight transport model.
The purpose of the paper is to analyze model uncertainty and economies of scale of the Swedish national freight transport model system Samgods to changes in its zone-to-zone base matrices. Even though economies of scale is important for freight transport, few studies analyze model uncertainty and economies of scale at a national level. Compared to many large scale networkbased freight models working on aggregated transport flows, an important feature in Samgods is that it simulates logistics behavior at a disaggregated firm level. The paper studies effects on total tonne- and vehicle-kilometre, modal split, consolidation and logistics costs when the base matrices are scaled up and down and estimates economies of scale for Swedish freight transports. The results indicate that the logistics model can find new logistics solutions for larger demand volumes, mainly by shifting freight to sea transport. If transport volume increases with one percent, average logistics cost per tonne is...
The purpose of the paper is to analyze model uncertainty and economies of scale of the Swedish national freight transport model system Samgods to changes in its zone-to-zone base matrices. Even though economies of scale is important for freight transport, few studies analyze model uncertainty...
Jonas Westin, Inge Vierth, Gerard de Jong, Rune Karlsson, Niclas A. Krüger, Magnus Johansson -
The field of travel behaviour dynamics represented a vibrant research area in the 1980s and the 1990s (Golob & Meurs, 1987; Golob, Kitamura, & Long, 1997; Kitamura, 1990), but has since, probably due to lack of mobility panel data, received relatively little attention by transportation researchers. Nevertheless, through the use of panel data (repeated measures of the same individuals) many new insights may be gained with respect to travel behaviour, insights that are fundamentally different from those that can possibly be gained from cross-sectional data.
The field of travel behaviour dynamics represented a vibrant research area in the 1980s and the 1990s (Golob & Meurs, 1987; Golob, Kitamura, & Long, 1997; Kitamura, 1990), but has since, probably due to lack of mobility panel data, received relatively little attention by transportation researchers. Nevertheless, through the use of panel data (repeated measures of the same individuals) many new insights may be gained with respect to travel behaviour, insights that are fundamentally different from those that can possibly be gained from cross-sectional data.
The field of travel behaviour dynamics represented a vibrant research area in the 1980s and the 1990s (Golob & Meurs, 1987; Golob, Kitamura, & Long, 1997; Kitamura, 1990), but has since, probably due to lack of mobility panel data, received relatively little attention by transportation...
Maarten Kroesen, Konstadinos G. Goulias -
Links between gender, activity/travel patterns and the life course have become a significant subject of inquiry in recent years. This paper draws upon a previous study that found that key events in the life course had significant effects on the complexity of trip and activity patterns. Some of these effects differed significantly between men and women. The panel data analysis presented here uses descriptive statistics to illustrate more clearly the patterns of time use before and after key events such as the birth of a child, entry into the labour market, or retirement. Further, regression models of time use changes for employed work, out-of-home leisure, escort, and time spent at home are presented. The data used is the German Mobility Panel (GMP) 1994 to 2014 in which households and their members are asked three times in three successive years to report the trips they made over a week. The results show the gendered effects of various key events on change in time use. Key events in partnership and the family affect women's time use more than men's, while for labour market events it is mostly the other way round.
Links between gender, activity/travel patterns and the life course have become a significant subject of inquiry in recent years. This paper draws upon a previous study that found that key events in the life course had significant effects on the complexity of trip and activity patterns. Some of these effects differed significantly between men and women. The panel data analysis presented here uses descriptive statistics to illustrate more clearly the patterns of time use before and after key events such as the birth of a child, entry into the labour market, or retirement. Further, regression models of time use changes for employed work, out-of-home leisure, escort, and time spent at home are presented. The data used is the German Mobility Panel (GMP) 1994 to 2014 in which households and their members are asked three times in three successive years to report the trips they made over a week. The results show the gendered effects of various key events on change in time use. Key events...
Links between gender, activity/travel patterns and the life course have become a significant subject of inquiry in recent years. This paper draws upon a previous study that found that key events in the life course had significant effects on the complexity of trip and activity patterns. Some of...
Joachim Scheiner -
This study investigates the impact of entry into parenthood on changes in car ownership. If entry into parenthood affects changes in car ownership, then delay or offset of entry into parenthood might also be an important explanation of recent car travel trends of young adults. This study analysed the impact of entry into parenthood on changes in the number of cars per household. Also, attention is given to the role of other related life course changes such as a change in urbanisation level, employment or household income. Using a unique data set, in which register data from 2011 and 2013 on the Dutch population, income and vehicle registration were combined, the study revealed that couples are more likely to enter car ownership and less likely to exit car ownership when they enter into parenthood. This implies that the delay of entry into parenthood might lead to later entry into car ownership and an increase in life time childlessness might lead to an overall decline in car ownership.
This study investigates the impact of entry into parenthood on changes in car ownership. If entry into parenthood affects changes in car ownership, then delay or offset of entry into parenthood might also be an important explanation of recent car travel trends of young adults. This study analysed the impact of entry into parenthood on changes in the number of cars per household. Also, attention is given to the role of other related life course changes such as a change in urbanisation level, employment or household income. Using a unique data set, in which register data from 2011 and 2013 on the Dutch population, income and vehicle registration were combined, the study revealed that couples are more likely to enter car ownership and less likely to exit car ownership when they enter into parenthood. This implies that the delay of entry into parenthood might lead to later entry into car ownership and an increase in life time childlessness might lead to an overall decline in car...
This study investigates the impact of entry into parenthood on changes in car ownership. If entry into parenthood affects changes in car ownership, then delay or offset of entry into parenthood might also be an important explanation of recent car travel trends of young adults. This study...
Abu Toasin Md Oakil, Dorien Manting, Hans Nijland -
The influence of the built environment on travel behaviour and the role of intervening variables such as socio-demographics and travel-related attitudes have long been debated in the literature. To date, most empirical studies have applied cross-sectional designs to investigate their bidirectional relationships. However, these designs provide limited evidence for causality. This study represents one of the first attempts to employ a longitudinal design on these relationships. We applied cross lagged panel structural equation models to a two-wave longitudinal dataset to assess the directions and strengths of the relationships between the built environment, travel behaviour and travel-related attitudes. Results show that the residential built environment has a small but significant influence on car use and travel attitudes. In addition, the built environment influenced travel-related attitudes indicating that people tend to adjust their attitudes to their built environment. This provides some support for land use policies that aim to influence travel behaviour.
The influence of the built environment on travel behaviour and the role of intervening variables such as socio-demographics and travel-related attitudes have long been debated in the literature. To date, most empirical studies have applied cross-sectional designs to investigate their bidirectional relationships. However, these designs provide limited evidence for causality. This study represents one of the first attempts to employ a longitudinal design on these relationships. We applied cross lagged panel structural equation models to a two-wave longitudinal dataset to assess the directions and strengths of the relationships between the built environment, travel behaviour and travel-related attitudes. Results show that the residential built environment has a small but significant influence on car use and travel attitudes. In addition, the built environment influenced travel-related attitudes indicating that people tend to adjust their attitudes to their built environment. This...
The influence of the built environment on travel behaviour and the role of intervening variables such as socio-demographics and travel-related attitudes have long been debated in the literature. To date, most empirical studies have applied cross-sectional designs to investigate their...
Paul van de Coevering, Kees Maat, Maarten Kroesen, Bert van Wee -
While most studies on mode choice behaviour and households are typically based on individual travel behaviour decisions, less is known about how relations inside households affect mode choice. This paper addresses this topic by examining intra- and inter-household variation in car use. The decision to use the car is modelled for home-based tours, based on data from the 2013 and 2014 waves of the Netherlands Mobility Panel. A multilevel framework is used to investigate mode choice behaviour at tour, individual and household level to account for the impact of individual and household characteristics on travel mode choice, interdependencies of individuals within their households and variation in individual travel mode choice and other characteristics over time. The results show that variability between households and individuals accounts for more than one third of the total variation in the mode choice of home-based tours. In dual-income households, intra-household interactions have a larger effect on car use than interhousehold interactions. Although only two panel waves are used, the model results show significant time effects on mode choice: if the same tour was also conducted in the previous year and one person changed working hours or work location, car use is less likely.
While most studies on mode choice behaviour and households are typically based on individual travel behaviour decisions, less is known about how relations inside households affect mode choice. This paper addresses this topic by examining intra- and inter-household variation in car use. The decision to use the car is modelled for home-based tours, based on data from the 2013 and 2014 waves of the Netherlands Mobility Panel. A multilevel framework is used to investigate mode choice behaviour at tour, individual and household level to account for the impact of individual and household characteristics on travel mode choice, interdependencies of individuals within their households and variation in individual travel mode choice and other characteristics over time. The results show that variability between households and individuals accounts for more than one third of the total variation in the mode choice of home-based tours. In dual-income households, intra-household interactions have...
While most studies on mode choice behaviour and households are typically based on individual travel behaviour decisions, less is known about how relations inside households affect mode choice. This paper addresses this topic by examining intra- and inter-household variation in car use. The...
Marie-José Olde Kalter, Karst T. Geurs -
It is of interest to transport policy makers to know whether interventions promoting sustainable transport modes can produce long-term changes in commute mode choices. Recent evidence has shown that a significant minority of commuters are variable in their day-to-day commute mode choices. This suggests that recognition should be given to day-to-day variability in investigating longer term commute behaviour changes. This paper introduces a panel survey that has been specifically designed to capture both day-to-day variability in commuting behaviour and longer term change in commuting behaviour. The analysis of the data accounts for day-to-day variability in commuting behaviour by identifying commute mode choice patterns at the weekly level. It then analyses transitions in commute mode choice patterns over time based on observations at three-monthly intervals. The results show that about one in four commuters mix driving alone to work with using other modes in a typical week and this is more likely for males, those with access to a bicycle and those working in another location during the week and less likely for those who work part-time. Changes in commute mode choices over a three month period are influenced by employment situational characteristics, access to mobility resources, satisfaction with commuting, awareness of sustainable transport measures and changes in life circumstances. Inspection of trajectories for those panel participants who responded to all five waves of the panel indicates that there are more cases of sustained switches between intermediate groups (e.g. car alone commuting to partial car alone commuting) than switches between extreme commuting groups (e.g. car alone commuting to non-car alone commuting). The styles are described in more detail in the remaining of this document.
It is of interest to transport policy makers to know whether interventions promoting sustainable transport modes can produce long-term changes in commute mode choices. Recent evidence has shown that a significant minority of commuters are variable in their day-to-day commute mode choices. This suggests that recognition should be given to day-to-day variability in investigating longer term commute behaviour changes. This paper introduces a panel survey that has been specifically designed to capture both day-to-day variability in commuting behaviour and longer term change in commuting behaviour. The analysis of the data accounts for day-to-day variability in commuting behaviour by identifying commute mode choice patterns at the weekly level. It then analyses transitions in commute mode choice patterns over time based on observations at three-monthly intervals. The results show that about one in four commuters mix driving alone to work with using other modes in a typical week and...
It is of interest to transport policy makers to know whether interventions promoting sustainable transport modes can produce long-term changes in commute mode choices. Recent evidence has shown that a significant minority of commuters are variable in their day-to-day commute mode choices. This...
Kiron Chatterjee, Ben Clark, Caroline Bartle -
In this paper data from 230 households observed in ten different occasions (waves) from 1989 to 2002 in the Puget Sound region are used to explore relationships among number of cars owned, number of trips driving alone, and number of trips sharing cars with household members. Using a mixture latent class Markov model we identify four distinct groups that are a High Mobility group with more cars and car trips, an Average Mobility group with lower car ownership and trips driving alone, a third group with relatively high car ownership but few car sharing trips, and a fourth group of Low Mobility characterized by the low car ownership and trips. Households change behaviour adapting to internal and external changes to their environment but they also anticipate changes and go through a "preparation" stage (e.g., adding another car in their fleet in expectation of adding another employed person). Land use plays a somewhat secondary role. The analysis also reveals three classes (hidden Markov chains) of households underlying behavioural dynamics with increases in the low car ownership categories (zero and one car per household), decreases in the high car ownership (three cars and four or more cars per household) and stable behaviour in the two cars per household group. Household membership in these classes is significantly influenced by householder ratings to parking availability, schedule flexibility, bus transfers, and day-to-day costs of driving. The findings here show attitudes and land use enhance understanding of longitudinal heterogeneity.
In this paper data from 230 households observed in ten different occasions (waves) from 1989 to 2002 in the Puget Sound region are used to explore relationships among number of cars owned, number of trips driving alone, and number of trips sharing cars with household members. Using a mixture latent class Markov model we identify four distinct groups that are a High Mobility group with more cars and car trips, an Average Mobility group with lower car ownership and trips driving alone, a third group with relatively high car ownership but few car sharing trips, and a fourth group of Low Mobility characterized by the low car ownership and trips. Households change behaviour adapting to internal and external changes to their environment but they also anticipate changes and go through a "preparation" stage (e.g., adding another car in their fleet in expectation of adding another employed person). Land use plays a somewhat secondary role. The analysis also reveals three classes (hidden...
In this paper data from 230 households observed in ten different occasions (waves) from 1989 to 2002 in the Puget Sound region are used to explore relationships among number of cars owned, number of trips driving alone, and number of trips sharing cars with household members. Using a mixture...
Elizabeth McBride, Jae Hyun Lee, Ansel M. Lundberg, Adam W. Davis, Konstadinos G. Goulias -
Recent empirical evidence suggests that travellers are becoming increasingly multimodal. Coinciding with this trend, a growing interest can be observed in the transport literature to study the concept of multimodality. Most studies, in this regard, have focused on assessing the determinants of multimodal travel behaviour. While it is interesting to know which factors, at a certain moment in time, affect the membership of mono/multimodal travel patterns, one general omission in the current literature relates to the questions how and why travellers switch between the mono/multimodal travel patterns over time. This study aims to fill this knowledge gap. To this end, a mixture latent Markov model is specified and estimated using data from the German mobility panel. Our mixture latent Markov models consist of latent travel patterns as well as latent mobility styles. To acquire insights on changes in travel behaviour various model specifications are tested. The travel data is best explained by a model consisting of five latent travel patterns and three mobility styles. The five travel patterns are can be conceived as (1) strict car users, (2) public transport and occasional car users, (3) car passengers, (4) car and bicycle users and (5) bicycle and occasional public transport users, and the three underlying mobility styles are identified as (1) habitual travellers, who stay in their respective pattern for three consecutive years, (2) car (in)dependent choice travellers, who switch within car and non-car patterns, and (3) car users with an alternative mode preference, who switch between car and noncar patterns. Overall, it is concluded that mixture latent Markov models are effective to reveal (heterogeneity in) transition patterns.
Recent empirical evidence suggests that travellers are becoming increasingly multimodal. Coinciding with this trend, a growing interest can be observed in the transport literature to study the concept of multimodality. Most studies, in this regard, have focused on assessing the determinants of multimodal travel behaviour. While it is interesting to know which factors, at a certain moment in time, affect the membership of mono/multimodal travel patterns, one general omission in the current literature relates to the questions how and why travellers switch between the mono/multimodal travel patterns over time. This study aims to fill this knowledge gap. To this end, a mixture latent Markov model is specified and estimated using data from the German mobility panel. Our mixture latent Markov models consist of latent travel patterns as well as latent mobility styles. To acquire insights on changes in travel behaviour various model specifications are tested. The travel data is best...
Recent empirical evidence suggests that travellers are becoming increasingly multimodal. Coinciding with this trend, a growing interest can be observed in the transport literature to study the concept of multimodality. Most studies, in this regard, have focused on assessing the determinants of...
Maarten Kroesen, Sander van Cranenburgh