Shared autonomous vehicles and their potential impacts on household vehicle ownership: An exploratory empirical assessment

Emerging transportation technologies have the potential to significantly reshape the transportation systems and household vehicle ownership. Key among these transportation technologies are the autonomous vehicles, particularly when introduced in shared vehicle fleets. In this paper, we focus on the potential impact that fleets of shared autonomous vehicles might have on household vehicle ownership. To obtain initial insights into this issue, we asked a sample of university personnel and members of the American Automobile Association as to how likely they would consider relinquishing one of their household's personal vehicles if shared autonomous vehicles were available (thus reducing their household vehicle ownership level by one). For single-vehicle households, this would be relinquishing their only vehicle, and for multivehicle households (households owning two or more vehicles) this would be relinquishing just one of their vehicles. Possible responses to the question about relinquishing a household vehicle if shared autonomous vehicles are present are: extremely unlikely, unlikely, unsure, likely, and extremely likely. To determine the factors that influence this response, random parameters ordered probit models are estimated to account for the likelihood that considerable unobserved heterogeneity is likely to be present in the data. The findings show that a wide range of socioeconomic factors affects people's likelihood of vehicle relinquishment in the presence of shared autonomous vehicles. Key among these are gender effects, generational elements, commuting patterns, and respondents' vehicle crash history and experiences. While people's opinions of shared autonomous vehicles are evolving with the continual introduction of new autonomous vehicle technologies and shifting travel behavior, the results of this study provide important initial insights into the likely effects of shared autonomous vehicles on household vehicle ownership.     

Governance options for a regional wireless public safety and transportation network

This paper examines several organizational governance options for CapWIN, an in-vehicle multi-jurisdictional communications and information system to be used by law enforcement, transportation, and public safety fleets in the Washington DC national capital region. The paper identifies and describes various organizational governance options for CapWIN, along with their institutional, constitutional, organizational, and financial characteristics and dynamics. An overview examination of various governance options is presented, including models and examples from across the country. From among these options, two structures are suggested as the most promising governance candidates. The research findings focus on the highest-potential candidate, the Interstate Compact Agreement and Organization.     

Deployment and utilization of plug-in electric vehicles in round-trip carsharing systems

Electric Vehicles (EVs) and Plug-in Hybrid Electric Vehicles (PHEVs) can reduce gasoline consumption, but increase vehicle acquisition costs and introduce operational constraints. We develop a comprehensive approach to EV/PHEV deployment and utilization in round-trip carsharing systems. First, we formulate and solve the tactical problem of utilizing a mix of gasoline vehicles and EVs/PHEVs to serve trip demand, using Mixed Integer Programming optimization to estimate the minimal gasoline consumption in a computationally efficient manner, and simulation to assess the effect of reservation order on realized gasoline consumption. Second, we use these results to inform the strategic deployment of EVs/PHEVs in the carsharing fleet, using meta-optimization. We implement our approach using data from a large carsharing provider. From the perspective of a carsharing operator, our results suggest that replacing some portion of existing gasoline fleets by EVs/PHEVs would result in gasoline savings likely to outweigh upfront investments and the constraints on vehicle utilization that it creates. Moreover, we find that easily implementable heuristics can capture some of these benefits, and that the integration of vehicle utilization patterns into the design of EV/PHEV deployment strategies can result in added benefits.     

The influence of greening the suppliers and green innovation on environmental performance and competitive advantage in Taiwan

Recently, many companies have recognized the concepts of green supply chain management or supply chain environmental management. However, relatively little research attention has been devoted to the consideration of relations between greening the supply chain, green innovation, environmental performance and competitive advantage. Hence, this paper aims to bridge this gap by providing empirical evidence to encourage companies to implement green supply chain and green innovation in order to improve their environmental performance, and to enhance their competitive advantage in the global market. A model is constructed to link the aforementioned constructs. Data were collected through a questionnaire-based survey across 124 companies from eight industry sectors in Taiwan. The data are analyzed using Structural Equation Modeling and the results from the final measurement model are used to evaluate the structural model that verifies the significance of the proposed relationships. A prominent result of this study is that greening the supplier through green innovation contributes significant benefits to the environmental performance and competitive advantage of the firm.     

Design and planning for green global supply chains under periodic review replenishment policies

We quantify the impact of jointly optimizing strategic network design and tactical inventory planning on the cost and CO₂ emissions of multi-echelon logistics networks. The obtained insights indicate that longer optimized replenishment cycles reduce a node’s transportation cost and CO₂ emissions but increase its inventory costs. Moreover, under a fixed replenishment cycle, a node’s service level increases when supplied by a satellite warehouse. Finally: (i) the costs of implementing optimal green network design decisions could be misleading if inventory planning is neglected, (ii) greening of supply chains could become expensive, (iii) current legislative CO₂ ton prices hardly influence logistics networks.     

Examining individuals preferences for hybrid electric and alternatively fuelled vehicles

This paper examines individuals motivations when purchasing vehicles, focusing upon what factors would encourage individuals to purchase hybrid electrical vehicle (HEV) or alternatively fuelled vehicle (AFV). AFVs in this paper refer to any cars run on alternatives to petrol and diesel. This research attempts to ascertain whether reductions in fuel costs, vehicle registration tax (VRT), or green house gas emissions would encourage individuals to purchase a HEV or an AFV instead of a conventional vehicle. VRT is an Irish tax that is levied on the purchase of new vehicles. One of the motivations to conduct this research was to examine a new car tax and VRT scheme introduced by the Irish government in 2008. This new policy rewards the purchase of environmentally friendly cars, with lower VRT and car tax rates. To understand individuals’ perceptions of these new taxes a survey was sent to recent customers of a car company in Ireland. The survey asked respondents about their recently purchased vehicle and how important they considered vehicle attributes such as environmental performance, fuel cost, and safety, before making their car purchase. The survey also contained a number of stated preference experiments that were designed to ascertain what factors influence individuals’ decisions when purchasing their new car. The results showed that respondents did not rate green house gas emissions or VRT as crucial attributes when purchasing a new vehicle. The vehicle attributes that respondents rated most highly were reliability, automobile safety, fuel costs, and the cost price. The majority of respondents agreed that HEVs and AFVs are better for the environment, cheaper to run than conventional vehicles and would be the vehicle of choice in ten years time.     

Heterogeneous preferences of green vehicles by vehicle size: Analysis of Seoul case

Although there are several policies for promoting green vehicles, green vehicles have yet to penetrate the market to the extent desired. To attain the goal, a complete understanding of consumers’ preferences of green vehicles is essential. This paper proposes and specifies the fuel-type choice models among conventional gasoline vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, and electric vehicles by vehicle size using the stated preferences data collected in Seoul, Korea. The results highlight the need to accommodate the correlation between similar alternatives and the unobserved heterogeneity within the context of choosing a green vehicle. The choice probabilities of green vehicles are affected by the relative impacts of the vehicles’ attributes and socio-demographic variables, and both of these variables are affected by the sizes of the vehicles. For compact size and mid-size vehicles, the effects of operating costs were less than those of purchase prices; however, for the subcompact vehicles, the effects of operating cost were greater than those of purchase price. The parameter of operating costs was not statistically significant in the full-size model. With respect to electric vehicles, the availability of fuel stations would be more important in Seoul than in the U.S. These results can also be useful for policy makers in that they provide information about the impact of green vehicles’ attributes on the choice probabilities of green vehicles.     

Fleet composition of commercial jet aircraft 1952–2005: Developments in uniformity and scale

The fleet composition of an airline is important in determining its costs and operational performance. This composition can be measured using numerical values. An index for measuring fleet uniformity is available, and a structured way of measuring fleet scale is introduced here. The history of all jet aircraft operated by commercial passenger or cargo airlines world-wide is analyzed both in general terms and using these measures. The analysis shows that uniformity in airline fleets has been steadily decreasing, while their scale has been steadily increasing.     

Modeling fuel saving investments and fleet management in the trucking industry: The impact of shipment performance on GHG emissions

Much has been written about the potential of technologies to reduce the greenhouse gas (GHG) emissions of trucking, but much less on the determinants of these investments. The Trucking Sector Trip Segmentation Model (TSTS) predicts how firms make these investments in the context of operating heterogeneous truck fleets to service the spatially dispersed demand of shippers. This analysis suggests that improving the performance of trucking (speeding up shipments) could reduce significantly GHG emissions: investments in technologies are incentivized by fuel savings accruing sooner. This effect could be potentially large in the US as trucking firms often discount the future heavily.     

Exploring social-ecological influences on commuter cycling in a midsize northern city: A qualitative study in Thunder Bay,Canada

Cycling is a healthy, affordable, and sustainable mode of transportation which offers myriad co-benefits to individuals and society at large. Despite these benefits, cycling remains underutilized as a mode of transportation, particularly in midsize cities and northern climates across North America. The specific objectives of this study were to: (1) explore the lived experiences and social-ecological determinants of utilitarian cycling in the context of a midsize city located in a northern climate, and (2) examine differences in social-ecological influences on utilitarian cycling between cyclists with and without access to a vehicle for transportation. Thirty cyclists over 18 years of age participated in semi-structured interviews. Data collected during the interviews were analysed using thematic analysis to describe the lived experiences of utilitarian cycling and to identify social-ecological determinants of utilitarian cycling. Fourteen key themes emerged from the data, confirming previous research illustrating that utilitarian cycling experiences, practices, and behaviours are determined by a plurality of interacting individual, social and cultural, regulatory and policy, and environmental factors. Across the study sample, differences in the experiences those of cyclists with and without access to a vehicle for transportation were identified across all levels of the social-ecological model. Drawing on our findings, we discuss three key lessons that highlight opportunities for promoting cycling as a mode of transportation in midsize and northern cities in North America in particular. These lessons include: 1) recognizing and addressing the influence of car culture; 2) shifting focus towards utilitarian cycling, and 3) identifying opportunities for addressing winter-related barriers. By drawing on the lived experiences of utilitarian cyclists, this research provides important directives for future policy-making, programming, and infrastructure development for the purposes of promoting cycling as a mode of transportation in other midsize cities in similar environments.     

Optimisation of the exploitation period of individual vehicles in freight transportation companies

The individual vehicle replacement problem typical for freight transportation companies is discussed in the paper. Two characteristic features of such problem are that transportation companies utilise vehicles with intensity decreasing with an age of vehicles and that managers of such companies first of all take into account economical criteria when planning vehicle replacements. The paper presents a single criterion, nonlinear, deterministic and discrete mathematical model of such a problem that minimises a total exploitation and ownership costs calculated per kilometre. The exact solution procedure is proposed here. The problem is solved as a real life case study. As a result, an average, economically optimal 5-year exploitation period of vehicles has been determined.     

The political economy of post-transition transportation policy in Hungary

This paper reviews transportation system trends in Hungary since the transition in 1989. It documents the continuation of rapid increases in private motor vehicle ownership and use despite a major economic downturn. Sharp increases in new highway investments are contrasted with a growing backlog of unmet maintenance and rehabilitation needs in the road, rail and public transit sectors. It then reviews recent political struggles over these policies, and the effectiveness of these policies in promoting employment, regional development, and a sustainable environment. It suggests that the dynamics of the post-industrial economy may have reduced the importance of highway sector investments relative to investments into human capital.     

Fair profit contract for a carrier collaboration framework in a green hub network under soft time-windows: Dual lexicographic max–min approach

This paper models a novel and practical bi-objective hub-location problem under a centralized carrier collaboration framework between one holding company and multiple carriers. The holding company first establishes a hub-and-spoke network in order to locate p hubs and to assign the center nodes to the located hubs. Then, it allocates the transportation routes of the hub network to the carriers. In contrast, the carriers should select an appropriate vehicle type to serve the transportation requests in a green hub network. The carriers are also able to meet the transportation requests within a certain time-window based on a soft time-window mechanism. Moreover, aiming to emphasize green transportation, a vehicle emission model is used to take into account CO₂ emissions of the vehicles where the fuel consumption is a function of speed level. Aiming to identify a win–win deal between the holding company and the carriers, a dual lexicographic max–min (LMM) approach is used in order to optimize their profits in a fair way. Finally, some numerical experiments are presented to demonstrate the applicability of the proposed methodology. The computational results show that not only the holding company and the carriers can better generate a fair profit contract among themselves using the LMM approach, but also both can obtain more profit in the worst case for their businesses rather than using the max–min approach. In addition, sensitivity analyses show that increasing the size of the soft time-window leads to a reduction in the delivery schedule violations, while results in raising the total profit. Moreover, the tax cost of fuel consumption as well as the number of potential vehicles has a substantial impact on both the fuel consumption and carrier’s profit.     

Application of system dynamics for evaluating truck weight regulations

In the situation of prevailing overweight transportation and difficult enforcement in China, this paper develops a methodological framework for truck weight regulation evaluation using System Dynamics. Composed of five interrelated subsystems, the framework is able to capture the highway, vehicle and freight variables that influence the effect of TWR and transportation efficiency over time. It specifically describes the development and use of the Truck Weight Regulation Evaluating Model for the highway freight system in Anhui province, China. The simulation results show that, among three policy alternatives, the moderate policy approach is the most appropriate option to solve the social and economic problems arising from overweight transportation in Anhui. In addition, some suggestions of TWR policy in China are also made in this paper.     

Socially optimal replacement of conventional with electric vehicles for the US household fleet

In this study, a framework is proposed for minimizing the societal cost of replacing gas-powered household passenger cars with battery electric ones (BEVs). The societal cost consists of operational costs of heterogeneous driving patterns' cars, government investments for charging deployment, and monetized environmental externalities. The optimization framework determines the timeframe needed for conventional vehicles to be replaced with BEVs. It also determines the BEVs driving range during the planning timeframe, as well as the density of public chargers deployed on a linear transportation network over time. We leverage data sets that represent US household driving patterns, as well as the automobile and the energy markets, to apply the model. Results indicate that it takes 8 years for 80% of our conventional vehicle sample to be replaced with electric vehicles, under the base case scenario. The socially optimal all-electric driving range is 204 miles, with chargers placed every 172 miles on a linear corridor. All public chargers should be deployed at the beginning of the planning horizon to achieve greater savings over the years. Sensitivity analysis reveals that the timeframe for the socially optimal conversion of 80% of the sample varies from 6 to 12 years. The optimal decision variables are sensitive to battery pack and vehicle body cost, gasoline cost, the discount rate, and conventional vehicles' fuel economy. Faster conventional vehicle replacement is achieved when the gasoline cost increases, electricity cost decreases, and battery packs become cheaper over the years.     

Employment centers and travel behavior: exploring the work commute of Mumbai’s rapidly motorizing middle class

In the Greater Mumbai Region (GMR), jobs and housing are agglomerating in nodes in the periphery of Mumbai City. However, current transportation investments focus on strengthening connections within Mumbai City, while these outlying nodes have received less attention. As housing and jobs move out, given limited travel choices, the need for mobility nudges many middle class Indian households into owning private vehicles. Using household travel survey data from the GMR, this paper develops an understanding of how worker’s trips are different for those who commute to the city versus the exurbs. Socio-economic and transportation indicators for middle class workers going to the city versus the exurbs show that these populations are quite similar demographically. However, those traveling to the exurbs, on average, tend to be at a socio-economic disadvantage with respect to income, education and out-of-pocket travel burdens. Those traveling to exurban work locations have shorter travel times and trip distances, and make much higher use of walking, biking, rickshaws, and motorized two-wheelers compared to commuters to Mumbai City. Across the GMR, car users travel longer and farther compared to motorized two-wheeler users. On average, traveling by a private vehicle is faster than bus or rickshaw travel revealing advantages of private vehicle use. These mode choices in the middle class have resulted in rapid motorization and negative externalities such as traffic congestion and emissions. Evidence of large increases in motorized two-wheelers and cars in India suggests that these modes will likely keep growing, unless competing efficient travel options are supplied.     

Future impacts of coal distribution constraints on coal costs

This study seeks to identify potential capacity constraints within the US rail network that could limit expanded use of coal for electricity generation and hydrogen fuel production. We estimate the costs of alleviating those constraints under various scenarios of future coal demand growth. By 2050, coal transportation is projected to increase 35–90% necessitating rail capital investments of $1.5–11.0 billion. These investments are within the range of historical expenditures in the railroad industry, so it is unlikely that delivered prices of coal will necessarily increase or that rail capacity will be a barrier to a future coal-based “Hydrogen Economy”.     

Measuring housing and transportation affordability: A case study of Melbourne,Australia

Housing affordability is traditionally measured using the percentage of household income spent on housing. An important cost that is usually overlooked in measuring location affordability is the transportation or accessibility costs. In this paper, we present a modeling approach, driven by urban open data, to measure location affordability that incorporates both housing and transportation costs. We apply the developed model to assess housing affordability in Melbourne, Australia as a case study. Results suggest that neighbourhoods that appear to be affordable when only housing cost is considered are not necessarily affordable when transportation costs are taken into account. A negative correlation between housing affordability and transportation affordability is observed. We also identify the presence of a strong spatial clustering pattern in the affordability measure across the study area. A major methodological contribution of the paper is the inclusion of comprehensive private vehicle costs and public transportation expenses in the model that contributes to a more robust estimation and understanding of location affordability. The model also distinguishes between different trip purposes. Results suggest that plans and policies to improve housing affordability should be made in coordination with transportation infrastructure investment plans to ensure effective and equitable outcomes. Nevertheless, the focus of the paper is more on the measurement of affordability; rather than reviewing and recommending housing related policies.     

Greening the lodging industry: Current status,trends and perspectives for green value

The purpose of this paper is to provide a critical review of extant knowledge on green lodging integration and a compilation of empirical studies that examine the greening of the lodging industry, published between 2003 and 2014. Empirical academic studies are grouped in three pillars: (a) studies that focus on corporate perspective, (b) studies that examine the role of governmental and trade organizations and (c) studies that focus on consumers’ perceptions in regard to hotels’ green integration. Accumulated knowledge is further presented in a structured way, through a Summary Table. Finally, the paper aims at setting the future research agenda in the area of green lodging by highlighting areas where results are equivocal, areas with evolving research attention and research issues that would enhance our understanding towards a greener lodging industry.     

Using principles of justice to assess the modal equity of regional transportation plans

While equity has been an important consideration for transportation planning agencies in the U.S. following the passage of Civil Rights Act of 1964 (Title VI specifically) and the subsequent Department of Transportation directives, there is little guidance on how to assess the distribution of benefits generated by transport investment programs. As a result, the distribution of these benefits has received relatively little attention in transportation planning, compared to transport-related burdens. Drawing on philosophies of social justice, we present an equity assessment of the distribution of accessibility in order to define the rate of “access poverty” among the population. We then apply this analysis to regional transportation plan scenarios from the San Francisco Bay Area, focusing on measures of differences between public transit and automobile access. The analysis shows that virtually all neighborhoods suffer from substantial gaps between car and public transport-based accessibility, but that the two proposed transportation investment programs reduce access poverty compared to the “no project” scenario. We also investigate how access and access poverty rates vary by demographic groups and map low-income communities within access impoverished areas, which could be the subject of further focused investments.