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Showing papers in "Transportation Research Part D-transport and Environment in 2015"


Journal ArticleDOI
TL;DR: In this article, the authors present a comprehensive overview of the drivers for and barriers against consumer adoption of plug-in EVs, as well as an overview of theoretical perspectives that have been utilized for understanding consumer intentions and adoption behavior towards EVs, identifying gaps and limitations in existing research and suggest areas in which future research would be able to contribute.
Abstract: In spite of the purported positive environmental consequences of electrifying the light duty vehicle fleet, the number of electric vehicles (EVs) in use is still insignificant. One reason for the modest adoption figures is that the mass acceptance of EVs to a large extent is reliant on consumers’ perception of EVs. This paper presents a comprehensive overview of the drivers for and barriers against consumer adoption of plug-in EVs, as well as an overview of the theoretical perspectives that have been utilized for understanding consumer intentions and adoption behavior towards EVs. In addition, we identify gaps and limitations in existing research and suggest areas in which future research would be able to contribute.

788 citations


Journal ArticleDOI
TL;DR: In this paper, the authors presented a system which can collect in-use EV data and vehicle driving data and analyzed both EV performance and driver behaviors to measure and estimate EVs' energy consumption.
Abstract: Use of electric vehicles (EVs) has been viewed by many as a way to significantly reduce oil dependence, operate vehicles more efficiently, and reduce carbon emissions. Due to the potential benefits of EVs, the federal and local governments have allocated considerable funding and taken a number of legislative and regulatory steps to promote EV deployment and adoption. With this momentum, it is not difficult to see that in the near future EVs could gain a significant market penetration, particularly in densely populated urban areas with systemic air quality problems. We will soon face one of the biggest challenges: how to improve efficiency for EV transportation system? This research takes the first step in tackling this challenge by addressing a fundamental issue, i.e. how to measure and estimate EVs’ energy consumption. In detail, this paper first presents a system which can collect in-use EV data and vehicle driving data. This system then has been installed in an EV conversion vehicle built in this research as a test vehicle. Approximately 5 months of EV data have been collected and these data have been used to analyze both EV performance and driver behaviors. The analysis shows that the EV is more efficient when driving on in-city routes than driving on freeway routes. Further investigation of this particular EV driver’s route choice behavior indicates that the EV user tries to balance the trade-off between travel time and energy consumption. Although more data are needed in order to generalize this finding, this observation could be important and might bring changes to the traffic assignment for future transportation system with a significant share of EVs. Additionally, this research analyzes the relationships among the EV’s power, the vehicle’s velocity, acceleration, and the roadway grade. Based on the analysis results, this paper further proposes an analytical EV power estimation model. The evaluation results using the test vehicle show that the proposed model can successfully estimate EV’s instantaneous power and trip energy consumption. Future research will focus on applying the proposed EV power estimation model to improve EVs’ energy efficiency.

341 citations


Journal ArticleDOI
TL;DR: The authors show that, compared to the 40 existing public charging stations, the 40 optimal ones selected by the model can increase electrified fleet VMT by 59% and 88% for slow and fast charging, respectively.
Abstract: The authors propose an optimization model based on vehicle travel patterns to capture public charging demand and select the locations of public charging stations to maximize the amount of vehicle-miles-traveled (VMT) being electrified. The formulated model is applied to Beijing, China as a case study using vehicle trajectory data of 11,880 taxis over a period of three weeks. The mathematical problem is formulated in GAMS modeling environment and Cplex optimizer is used to find the optimal solutions. Formulating mathematical model properly, input data transformation, and Cplex option adjustment are considered for accommodating large-scale data. The authors show that, compared to the 40 existing public charging stations, the 40 optimal ones selected by the model can increase electrified fleet VMT by 59% and 88% for slow and fast charging, respectively. Charging demand for the taxi fleet concentrates in the inner city. When the total number of charging stations increase, the locations of the optimal stations expand outward from the inner city. While more charging stations increase the electrified fleet VMT, the marginal gain diminishes quickly regardless of charging speed.

219 citations


Journal ArticleDOI
TL;DR: The Worldwide harmonized Light Duty Test Cycle (WLTC) as discussed by the authors was developed under the Working Party on Pollution and Energy (GRPE) and sponsored by the European Union (with Switzerland) and Japan.
Abstract: This paper presents the World-wide harmonized Light duty Test Cycle (WLTC), developed under the Working Party on Pollution and Energy (GRPE) and sponsored by the European Union (with Switzerland) and Japan. India, Korea and USA have also actively contributed. The objective was to design the harmonized driving cycle from “real world” driving data in different regions around the world, combined with suitable weighting factors. To this aim, driving data and traffic statistics of light duty vehicles use were collected and analyzed as basic elements to develop the harmonized cycle. The regional driving data and weighting factors were then combined in order to develop a unified database representing the worldwide light duty vehicle driving behavior. From the unified database, short trips were selected and combined to develop a driving cycle as representative as possible of the unified database. Approximately 765,000 km of data were collected, covering a wide range of vehicle categories, road types and driving conditions. The resulting WLTC is an ensemble of three driving cycles adapted to three vehicle categories with different power-to-mass ratio (PMR). It has been designed as a harmonized cycle for the certification of light duty vehicles around the world and, together with the new harmonized test procedures (WLTP), will serve to check the compliance of vehicle pollutant emissions with respect to the applicable emissions limits and to establish the reference vehicle fuel consumption and CO2 performance.

208 citations


Journal ArticleDOI
TL;DR: A new evaluation system for the location selection of a CLC from a sustainability perspective using a fuzzy multi-attribute group decision making (FMAGDM) technique based on a linguistic 2-tuple to evaluate potential alternative CLC locations.
Abstract: City Logistics Centers (CLC) are an important part of the modern urban logistics system, and the selection of the location of a CLC has become a key problem in logistics and supply chain management. Integrating the economic, environmental, and social dimensions of sustainable development, this paper presents a new evaluation system for the location selection of a CLC from a sustainability perspective. A fuzzy multi-attribute group decision making (FMAGDM) technique based on a linguistic 2-tuple is used to evaluate potential alternative CLC locations. In this method, the linguistic evaluation values of all the evaluation criteria are transformed into linguistic 2-tuples. A new 2-tuple hybrid ordered weighted averaging (THOWA) operator is presented to aggregate the overall evaluation values of all experts into a collective evaluation value for each alternative, which is then used to rank and select alternative CLC locations. An application example is provided to validate the method developed and to highlight the implementation, practicality, and effectiveness by comparing with the fuzzy Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method.

198 citations


Journal ArticleDOI
TL;DR: In this paper, an extended car-following model was proposed to study the influence of the driver's bounded rationality on micro driving behavior and fuel consumption, CO, HC and NOX of each vehicle under two typical cases.
Abstract: In this paper, we propose an extended car-following model to study the influences of the driver’s bounded rationality on his/her micro driving behavior, and the fuel consumption, CO, HC and NOX of each vehicle under two typical cases, where Case I is the starting process and Case II is the evolution process of a small perturbation. The numerical results indicate that considering the driver’s bounded rationality will reduce his/her speed during the starting process and improve the stability of the traffic flow during the evolution of the small perturbation, and reduce the total fuel consumption, CO, HC and NOX of each vehicle under the above two cases.

186 citations


Journal ArticleDOI
TL;DR: In this article, 66 randomly selected participants were given an e-bike to use for a limited period of time and the results compared with those of a control group (N = 160) E-bike cycling trips increased from 09 to 14 per day, distance from 48 km to 103 km, whereas with the control group there was no increase in cycling.
Abstract: In Norway, as in many countries, a political goal is to increase bicycle use, and the e-bike is promising in this respect However, concerns have been raised about mode-share effects It has been argued that if the e-bike’s only function is in cycling becoming cycling with electric assistance, there would be no benefit to either the environment or public health Little is yet known about the use of the e-bike, or of its potential in reducing motorized travel In the current study, 66 randomly selected participants were given an e-bike to use for a limited period of time and the results compared with those of a control group (N = 160) E-bike cycling trips increased from 09 to 14 per day, distance from 48 km to 103 km and, as a share of all transport, from 28% to 48%, whereas with the control group there was no increase in cycling The effect of the e-bike increased with time, indicating a learning effect among users, and was greater for female than for male cyclists There were no differences with age Overall, the results suggest that the e-bike is indeed practical for everyday travel

155 citations


Journal ArticleDOI
TL;DR: The environmental, economic, and social performance of electric two-wheelers are reviewed, demonstrating that these are generally more energy efficient and less polluting than conventionally-powered motor vehicles.
Abstract: Electrification is widely considered as a viable strategy for reducing the oil dependency and environmental impacts of road transportation. In pursuit of this strategy, most attention has been paid to electric cars. However, substantial, yet untapped, potentials could be realized in urban areas through the large-scale introduction of electric two-wheelers. Here, we review the environmental, economic, and social performance of electric two-wheelers, demonstrating that these are generally more energy efficient and less polluting than conventionally-powered motor vehicles. Electric two-wheelers tend to decrease exposure to pollution as their environmental impacts largely result from vehicle production and electricity generation outside of urban areas. Our analysis suggests that the price of e-bikes has been decreasing at a learning rate of 8%. Despite price differentials of 5000 ± 1800 EUR2012 kW h−1 in Europe, e-bikes are penetrating the market because they appear to offer an apparent additional use value relative to bicycles. Mid-size and large electric two-wheelers do not offer such an additional use value compared to their conventional counterparts and constitute niche products at price differentials of 700 ± 360 EUR2012 kW−1 and 160 ± 90 EUR2012 kW−1, respectively. The large-scale adoption of electric two-wheelers can reduce traffic noise and road congestion but may necessitate adaptations of urban infrastructure and safety regulations. A case-specific assessment as part of an integrated urban mobility planning that accounts, e.g., for the local electricity mix, infrastructure characteristics, and mode-shift behavior, should be conducted before drawing conclusions about the sustainability impacts of electric two-wheelers.

147 citations


Journal ArticleDOI
TL;DR: In this article, the authors used telephone survey data consisting of 1823 valid samples from across Seoul, a city characterized by a high population density and a well-established public transportation system.
Abstract: This study intends to empirically verify Jacobs’ urban vitality theory, which was based on the observations of her New York City neighborhood in the mid-20th century. To examine the relationship between the residential built environment and walking activity, we used telephone survey data consisting of 1823 valid samples from across Seoul, a city characterized by a high population density and a well-established public transportation system. Respondents were asked questions about their residential location, their demographic and socioeconomic characteristics, and their walking activities. This study then used geographic information systems to measure objective indicators of built environment variables within 500-meter buffer areas based on the home addresses of the respondents. Then, this study constructed multilevel regression models with walking activity as the dependent variable. Our results indicated that walking activity is associated with Jacobs’ six conditions for urban vitality, including land use mix, density, block size, building age, accessibility, and border vacuums.

121 citations


Journal ArticleDOI
TL;DR: In this article, the authors developed a systematic energy consumption estimation approach suitable for EV actual driving cycles from a physical and statistical view, and the results show that the proposed modeling approach represents a significant accuracy improvement in the estimation of real-world energy consumption.
Abstract: The use of electric vehicles (EVs) is viewed as an attractive option to reduce CO2 emissions and fuel consumption resulted from transport sector, but the popularization of EVs has been hindered by the cruising range limitation and the charging process inconvenience. Energy consumption characteristics analysis is the important foundation to study charging infrastructures locating, eco-driving behavior and energy saving route planning, which are helpful to extend EVs’ cruising range. From a physical and statistical view, this paper aims to develop a systematic energy consumption estimation approach suitable for EV actual driving cycles. First, by employing the real second-by-second driving condition data collected on typical urban travel routes, the energy consumption characteristics analysis is carried out specific to the microscopic driving parameters (instantaneous speed and acceleration) and battery state of charge (SOC). Then, based on comprehensive consideration of the mechanical dynamics characteristics and electric machine system of the EVs, a set of energy consumption rate estimation models are established under different operation modes from a statistical perspective. Finally, the performance of proposed model is fully evaluated by comparing with a conventional energy consumption estimation method. The results show that the proposed modeling approach represents a significant accuracy improvement in the estimation of real-world energy consumption. Specifically, the model precision increases by 25.25% in decelerating mode compared to the conventional model, while slight improvement in accelerating and cruising mode with desirable goodness of fit.

119 citations


Journal ArticleDOI
TL;DR: In this paper, a web-based survey was conducted for the participants of the Seoul EVSP, asking their satisfaction levels for the components of the EVSP and found that participants' social and economic perspectives were the most important factors affecting the participants' attitudes.
Abstract: There are growing concerns on traffic congestion, climate change and parking problems in major cities. Faced with these concerns, policy makers have sought sustainable transportation options including electric vehicle sharing programs (EVSPs). The city of Seoul with 10 million people also has recently launched an EVSP to provide citizens with an alternative travel mode. This study attempts to explore factors affecting the EVSP participants’ attitudes about car ownership and program participation. To do this, a web-based survey was conducted for the participants of the Seoul EVSP, asking their satisfaction levels for the components of the EVSP. Then, using 533 responses of 1772 EVSP members (a response rate of 30%), ordered probit models were developed for three types of attitudes: (1) willingness to dispose of a car, (2) willingness to purchase an EV and (3) willingness to continue participating in the EVSP. The estimated models suggested that participants’ social and economic perspectives were the most important factors affecting the participants’ attitudes. In addition, the attitudes varied depending on personal characteristics such as gender, age and income. Although this study was conducted in the early stage of an EVSP, its results are expected to provide insights into a better EVSP design.

Journal ArticleDOI
TL;DR: In this paper, a detailed NO x, SO 2 and PM 25 emissions for cruise ships in the five busiest Greek ports (i.e., Piraeus, Santorini, Mykonos, Corfu and Katakolo) for year 2013 were analyzed in terms of gas species, seasonality and activity.
Abstract: Detailed NO x , SO 2 and PM 25 emissions have been estimated for cruise ships in the five busiest Greek ports (ie Piraeus, Santorini, Mykonos, Corfu and Katakolo) for year 2013 The emissions were analyzed in terms of gas species, seasonality and activity The total in-port inventory of cruise shipping accounted to 27427 tons: with NO x being dominant (18875 tons), followed by SO 2 and PM 25 (7609 and 943 tons respectively) Emissions during hotelling corresponded to 885% of total and have significantly outweighed those produced during ships’ maneuvering activities (115% of total) Seasonality was found to play a major role, as summer emissions and associated impacts were significantly augmented The anticipated health impacts of ship emissions can reach to €243 million or to €53 per passenger proving the necessity of control of the emissions produced by cruise ships in port cities or policy and measures towards a more efficient cruise industry

Journal ArticleDOI
TL;DR: In this article, two speed optimization problems for ships that sail in and out of Emission Control Areas (ECAs) with strict limits on sulfur emissions are investigated. But the authors focus on the point at which the ship crosses the ECA boundary.
Abstract: This paper deals with two speed optimization problems for ships that sail in and out of Emission Control Areas (ECAs) with strict limits on sulfur emissions. For ships crossing in and out of ECAs, such as deep-sea vessels, one of the common options for complying with these limits is to burn heavy fuel oil (HFO) outside the ECA and switch to low-sulfur fuel such as marine gas oil (MGO) inside the ECA. As the prices of these two fuels are generally very different, so may be the speeds that the ship will sail at outside and inside the ECA. The first optimization problem examined by the paper considers an extension of the model of Ronen (1982) in which ship speeds both inside and outside the ECA are optimized. The second problem is called the ECA refraction problem, due to its conceptual similarity with the refraction problem when light travels across two different media, and also involves optimizing the point at which the ship crosses the ECA boundary. In both cases the objective of the problem is to maximize daily profit. In addition to mathematical formulations, examples and sensitivity analyses are presented for both problems.

Journal ArticleDOI
TL;DR: In this article, the authors present an estimation and analysis of ship exhaust emissions and their externalities in the popular cruise destinations of Dubrovnik (Croatia) and Kotor (Montenegro) along the eastern coast of the Adriatic Sea.
Abstract: This paper presents an estimation and analysis of ship exhaust emissions and their externalities in the popular cruise destinations of Dubrovnik (Croatia) and Kotor (Montenegro) along the eastern coast of the Adriatic Sea. To this extent, the recent record (2012–2014) of cruise ships calling at these ports is used to model and estimate the ship exhaust emission inventories and externalities within the associated bays and ports. The results indicate that cruise ship traffic produces continuously increasing air pollution in both ports over recent years. More importantly, however, the analysis of the ship operating characteristics reveals that for any given ship traffic involving specific vessels using marine fuel of a given quality, the presence of other factors (e.g. berth availability, berth accessibility etc) can also influence the ship emission levels. This is particularly evident in the case of the port of Kotor where berth space insufficiency dictates the need for ship anchorage thus leading to increased air pollution and costs of associated damage. The application and results of the aforementioned ship activity-based methodology to the ports of Dubrovnik and Kotor improves our understanding of ship emissions in cruise bays and ports, and contributes toward the implementation of port policies for the effective control of air quality in such environmentally sensitive locations.

Journal ArticleDOI
TL;DR: In this article, the authors investigate the energy management system and control strategies effect on fuel consumption, air pollution and performance of hybrid vehicles in various driving cycles, where the combined feedback-feedforward architecture of the power-split hybrid electric vehicle based on Toyota Prius configuration is modeled, together with necessary dynamic features of subsystem or components in ADVISOR.
Abstract: Reduction of greenhouse gas emission and fuel consumption as one of the main goals of automotive industry leading to the development hybrid vehicles. The objective of this paper is to investigate the energy management system and control strategies effect on fuel consumption, air pollution and performance of hybrid vehicles in various driving cycles. In order to simulate the hybrid vehicle, the combined feedback–feedforward architecture of the power-split hybrid electric vehicle based on Toyota Prius configuration is modeled, together with necessary dynamic features of subsystem or components in ADVISOR. Multi input fuzzy logic controller developed for energy management controller to improve the fuel economy of a power-split hybrid electric vehicle with contrast to conventional Toyota Prius Hybrid rule-based controller. Then, effects of battery’s initial state of charge, driving cycles and road grade investigated on hybrid vehicle performance to evaluate fuel consumption and pollution emissions. The simulation results represent the effectiveness and applicability of the proposed control strategy. Also, results indicate that proposed controller is reduced fuel consumption in real and modal driving cycles about 21% and 6% respectively.

Journal ArticleDOI
TL;DR: In this article, the authors present a survey on the current and innovative strategies to remove particles from marine diesel engine exhausts, along with a critical review of the most recent findings on ships emitted particles.
Abstract: Marine diesel engines emit particles that have a complex nature, being composed by carbonaceous particles, with size spanning from few nanometres to less than one micron, and inorganic particles of micron size mainly made by ashes and sulphates. On a global scale, international shipping is responsible for few percentages of the particulate matter emissions, which also affect climate, but the regional distribution of naval traffic suggests the insurgence of significant exposure risk for population living along the coastal areas, due to chronic exposure effects. Specific strategies should be implemented to reduce the emissions of all the components of particulate matter. This paper aims to present a survey on the current and innovative strategies to remove particles from marine diesel engine exhausts, along with a critical review of the most recent findings on ships emitted particles. Evidences on physical–chemical properties, toxicology and emission factors of the particles were reported. This survey indicates that several strategies can provide a significant reduction of particulate matter emissions from ships and integration between innovative after-treatment systems, ships design and operation procedures can potentially lead to overall reduction of more than 99% even with parallel fuel savings.

Journal ArticleDOI
TL;DR: In this paper, the authors assess the current levels of visibility for public PEV charging infrastructure within Canada and identify whether or not a statistically significant relationship exists between consumer awareness of public charging infrastructure and interest in purchasing a PEV.
Abstract: Policymakers often seek to increase the visibility of plug-in electric vehicle (PEV) chargers in public locations in effort to build familiarity and interest in PEVs. However, it is not clear if the visibility of public charging stations actually has an impact on PEV demand. The purposes of the present study are to (1) assess the current levels of visibility for public PEV charging infrastructure within Canada and (2) identify whether or not a statistically significant relationship exists between consumer awareness of public charging infrastructure and interest in purchasing a PEV. We use data collected from a sample of 1739 Canadian new-vehicle buyers in 2013. About 18% of Canadian respondents have seen at least one public charger, while the proportion is highest in British Columbia (31%). We find a significant bivariate relationship between public charger awareness and PEV interest. However, when controlling for multiple explanatory variables in regression analyses, the relationship is weak or non-existent. While perceived existence of at least one charger exhibits no significant relationship with PEV interest, perceived existence of multiple chargers can have a weak but significant relationship. Thus, public charger awareness is not a strong predictor of PEV interest; other variables are more important, such as the availability of level 1 (110/120-volt) charging at home.

Journal ArticleDOI
TL;DR: In this paper, a methodology for the application of multi-criteria decision-making (MCDM) on the technology selection for emissions reduction from shipping under uncertainties and incomplete information is described.
Abstract: This paper describes a methodology for the application of Multi-Criteria Decision-Making (MCDM) on the technology selection for emissions reduction from shipping under uncertainties and incomplete information. Nine criteria in four aspects, including technological (maturity), economic (capital cost and operation cost), environmental (effects of SO x , NO x , GHG, and PM reduction), and social–political aspects (government support and social acceptability), were used for the sustainability assessment. The study aims at developing the methodology for technology selection for emissions reduction from shipping by combining Fuzzy Analytic Hierarchy Process (AHP) and VIKOR. Fuzzy AHP was used to determine the weights of the evaluation criteria and the relative performance of the alternatives with respect to each evaluation criterion, and VIKOR was used to prioritize the alternative technologies. The two methods of VIKOR and the traditional AHP were combined to validate the proposed methodology. Three alternative technologies of low sulphur fuel, scrubber and LNG were studied using the proposed model, and the results indicate that the proposed methodology is capable of assisting the decision-makers to select the most sustainable technology for emissions reduction from shipping under uncertainties and incomplete information.

Journal ArticleDOI
TL;DR: In this article, a method to develop representative driving cycles using simulated data from a calibrated microscopic traffic simulation model of the Toronto Waterfront Area is introduced, which is calibrated to reflect road counts, link speeds, and accelerations using a multiobjective genetic algorithm.
Abstract: Driving cycles are an important input for state-of-the-art vehicle emission models. Development of a driving cycle requires second-by-second vehicle speed for a representative set of vehicles. Current standard driving cycles cannot reflect or forecast changes in traffic conditions. This paper introduces a method to develop representative driving cycles using simulated data from a calibrated microscopic traffic simulation model of the Toronto Waterfront Area. The simulation model is calibrated to reflect road counts, link speeds, and accelerations using a multi-objective genetic algorithm. The simulation is validated by comparing simulated vs. observed passenger freeway cycles. The simulation method is applied to develop AM peak hour driving cycles for light, medium and heavy duty trucks. The demonstration reveals differences in speed, acceleration, and driver aggressiveness between driving cycles for different vehicle types. These driving cycles are compared against a range of available driving cycles, showing different traffic conditions and driving behaviors, and suggesting a need for city-specific driving cycles. Emissions from the simulated driving cycles are also compared with EPA’s Heavy Duty Urban Dynamometer Driving Schedule showing higher emission factors for the Toronto Waterfront cycles.

Journal ArticleDOI
TL;DR: In this paper, the urban environmental correlates and determinants of bicycle use for commuting (bicycle commuting) among the working or studying population in Barcelona, Spain were assessed by multinomial logistic regression models adjusted for potential confounders and covariates.
Abstract: Objective Bicycle use for commuting is being encouraged not only to address physical inactivity, but also vehicular congestion, air pollution and climate change. The current study aimed to ascertain the urban environmental correlates and determinants of bicycle use for commuting (bicycle commuting) among the working or studying population in Barcelona, Spain. Methods Adults ( n = 769; 52% females) recruited whilst commuting within Barcelona (Spain) responded to a comprehensive telephone survey concerning their travel behaviour. Based upon responses collected from June 2011 to May 2012, participants were categorised into four groups: frequent bicyclists, infrequent bicyclists, willing non-bicyclists, and unwilling non-bicyclists. The determinants of frequency and willingness (propensity) to commute by bicycle were assessed by multinomial logistic regression models adjusted for potential confounders and covariates. Results The number of public bicycle stations surrounding the home address and amount of greenness surrounding the work/study address were significant positive determinants of bicycle commuting propensity. On the other hand, the number of public transport stations surrounding the home address and elevation of the work/study address were significant negative determinants of bicycle commuting propensity. Individual age, education level, gender, nationality, physical activity level and commute distance significantly affected this propensity. Conclusion Greater availability of public bicycle stations and higher levels of urban greenness may increase bicycle use by adults commuting within a city such as Barcelona, Spain. Electrically-assisted public bicycles may address the challenge of elevation, making this system a more competitive mode against traditional motorised public transport.

Journal ArticleDOI
TL;DR: In this paper, a multi-objective optimization model was developed integrating the three elements in order to optimize the asphalt pavement maintenance plans at the project level, and the developed model revealed the quantitatively interactive relationship of the three objectives and helps optimizing the asphalt paving maintenance plans.
Abstract: Traditionally, asphalt pavement maintenance mainly considers pavement performance and cost and largely ignores the environment while substantial amount of environmental burdens are released in the process. In this study, a multi-objective optimization model was developed integrating the three elements in order to optimize the asphalt pavement maintenance plans at the project level. Pavement performance element was decided as the multiplier of pavement serviceability index and traffic volume. Cost element was represented by the net present value, including components of agency cost, vehicle operation cost and salvage value. Environmental element, integrating energy consumption, global warming potential, acidification potential and respiratory effects potential, was measured by the life cycle assessment model. A hypothetic asphalt pavement maintenance case study was conducted using the developed multi-objective optimization model and harvested 103 sets of feasible combinations of maintenance plans, each of which is non-dominated by the others. Trade-offs analysis was performed among the three objectives and visualized in both two- and three-dimension forms. It is found there is an opportunity of reducing the cost and environmental impacts to 80.3% and 77.8% and increasing the pavement performance to 146.6% compared to the base case. However, they are mutually compromised and cannot be reached simultaneously. The developed model reveals the quantitatively interactive relationship of the three objectives and helps optimize the asphalt pavement maintenance plans.

Journal ArticleDOI
TL;DR: In this article, the investments efficiency of sulphur oxide (SOx) scrubber installation to comply with the requirements of MARPOL 73/78 Annex VI, which sets 0.1% SOx limits in 2015 in Emission Control Area (ECA) and 0.5% in 2020 globally.
Abstract: The article analyses the investments efficiency of sulphur oxide (SOx) scrubber installation to comply with the requirements of MARPOL 73/78 Annex VI, which sets 0.1% SOx limits in 2015 in Emission Control Area (ECA) and 0.5% in 2020 globally. There are two most realistic technologies to reduce SOx emission suitable for existing fleet: low sulphur fuel; scrubber. Mentioned technologies are compared and economic issues of each are analyzed in the article. The comparison of the technologies shows that no matter which technology will be selected each will require the additional costs: capital and operating costs, loss of profits due to the reduce of cargo capacity. That is why the technology introduction will be considered as investments in the article. Each of mentioned technology has certain specific of the investments. Therefore, the evaluation of the investments efficiency should be carried out by comparing the different technologies (in our case scrubber and low sulphur fuel) that meet the requirements of MARPOL 73/78. Investments efficiency in technology will be evaluated by cash flow modeling during the billing period covering the time interval from the technology introduction to the completion of use. The concept of cash flow allows forming a systematic view of funding and determining the dynamics of the financial effects at the each stage of technology introduction. In turn, a comparative analysis of technologies will identify the best option of investment applying to a particular ship.

Journal ArticleDOI
TL;DR: In this article, a computationally efficient and theoretically rigorous dynamic traffic assignment (DTA) model and its solution algorithm for a number of emerging emissions and fuel consumption related applications that require both effective microscopic and macroscopic traffic stream representations are presented.
Abstract: This paper presents a computationally efficient and theoretically rigorous dynamic traffic assignment (DTA) model and its solution algorithm for a number of emerging emissions and fuel consumption related applications that require both effective microscopic and macroscopic traffic stream representations. The proposed model embeds a consistent cross-resolution traffic state representation based on Newell’s simplified kinematic wave and linear car following models. Tightly coupled with a computationally efficient emission estimation package MOVES Lite, a mesoscopic simulation-based dynamic network loading framework DTALite is adapted to evaluate traffic dynamics and vehicle emission/fuel consumption impact of different traffic management strategies.

Journal ArticleDOI
TL;DR: In this article, a comparative analysis of environmental impacts for different scenarios of a typical local road is carried out, where different road construction techniques were considered with regards to the whole structure and compared in order to identify the best alternative in terms of environmental sustainability.
Abstract: The aim of this work is to carry out a comparative analysis of environmental impacts for different scenarios of a typical local road. Life Cycle Assessment (LCA) is the modeling tool used to quantify and characterize comparative environmental impacts. In carrying out this specific application of the LCA, different road construction techniques were considered with regards to the whole structure and compared in order to identify the best alternative in terms of environmental sustainability. So far, in fact, typical LCA frameworks of roads have focused on recycled materials for pavement layers only, thus neglecting study of the materials used in the embankment or in the subgrade. In this study, these materials were included too, in order to prove the environmental benefit of using a sustainable technique such as in situ stabilization of fine soils with lime (typically dumped clayey soils) in order to reduce the need for virgin material for embankment and subgrade construction. When using different percentages of recycled materials (such as reclaimed asphalt pavement – RAP) in the bituminous layer or in the foundation, the analysis of the functional unit studied shows a significant reduction of energy consumption and pollutant emissions mainly due to transportation of materials involved, in this way increasing the environmental performance of the road. Another important consideration is that the use of fine soils stabilized with lime “in situ”, instead of dumping it, not only is a good technical solution for improving soil mechanical properties, but it also produces a reduction of energy consumption and of pollutant emissions. It is noticeable that this technique results in a significant reduction of pollutant emissions due the transportation of involved materials, increasing the environmental performance of the road.

Journal ArticleDOI
TL;DR: In a case study of a Norwegian heavy-duty truck transport company, this article analyzed data generated by the online fleet management system Dynafleet to find out what influenced fuel consumption.
Abstract: In a case study of a Norwegian heavy-duty truck transport company, we analyzed data generated by the online fleet management system Dynafleet. The objective was to find out what influenced fuel consumption. We used a set of driving indicators as explanatory variables: load weight, trailer type, route, brake horsepower, average speed, automatic gearshift use, cruise-control use, use of more than 90% of maximum torque, a dummy variable for seasonal variation, use of running idle, use of driving in highest gear, brake applications, number of stops and rolling without engine load. We found, via multivariate regression analysis and corresponding mean elasticity analysis, that with driving on narrow mountainous roads, variables associated with infrastructure and vehicle properties have a larger influence than driver-influenced variables do. However, we found that even under these challenging infrastructure conditions, driving behavior matters. Our findings and analysis could help transport companies decide how to use fleet management data to reduce fuel consumption by choosing the right vehicle for each transportation task and identifying environmentally and economically benign ways of driving.

Journal ArticleDOI
TL;DR: In this paper, a mixed logit model with unobserved heterogeneity is applied to panel data extracted from a two-year field trial on battery electric vehicle usage in Japan, and the authors aim to examine choice behavior in respect of the time at which EV users charge their vehicles.
Abstract: This paper aims to examine choice behavior in respect of the time at which battery electric vehicle users charge their vehicles. The focus is on normal charging after the last trip of the day, and the alternatives presented are no charging, charging immediately after arrival, nighttime charging, and charging at other times. A mixed logit model with unobserved heterogeneity is applied to panel data extracted from a two-year field trial on battery electric vehicle usage in Japan. Estimation results, obtained using separate models for commercial and private vehicles, suggest that state of charge, interval in days before the next travel day, and vehicle-kilometers to be traveled on the next travel day are the main predictors for whether a user charges the vehicle or not, that the experience of fast charging negatively affects normal charging, and that users tend to charge during the nighttime in the latter half of the trial. On the other hand, the probability of normal charging after the last trip of a working day is increased for commercial vehicles, while is decreased for private vehicles. Commercial vehicles tend not to be charged when they arrival during the nighttime, while private vehicles tend to be charged immediately. Further, the correlations of nighttime charging with charging immediately and charging at other times reveal that it may be possible to encourage charging during off-peak hours to lessen the load on the electricity grid. This finding is supported by the high variance for the alternative of nighttime charging.

Journal ArticleDOI
TL;DR: In this article, the authors deal with aircraft noise impact on natural environments from a multiple innovative perspective and combine: noise modeling, field measurements, soundscape audibility, human perception and spatial pattern tools for assessing the chronic growing outdoor noise pollution of ecosystems at landscape scale.
Abstract: Global transportation growth causes several disproportionate impacts on the environment as, for instance, noise pollution which is related to negative effects on human health but also to quiet natural areas decline and biodiversity loss. Besides, sound is a component of ecosystems severely threatened by transportation noise disturbance which is related to negative effects on ecosystem functions. This study deals with aircraft noise impact on natural environments from a multiple innovative perspective. It complementarily combines: noise modeling, field measurements, soundscape audibility, human perception and spatial pattern tools for assessing the chronic growing outdoor noise pollution of ecosystems at landscape scale. Firstly, noticeable soundscape degradation from aircraft overflights has been found causing severe acoustic fragmentation and disruptions in the quietness of a national park in Spain (European Union). Air traffic caused sound pressure levels to increase by approximately 8 decibels from natural ambient levels. Secondly, spatial pattern tools together with noise mapping have been found to be useful in providing decision support for decisions-making through anthropogenic noise impact assessment on the natural environment. Finally, public opinion did not perceive aircraft noise-disruption as being as relevant as that quantified by technical procedures. Although 82% of visitors agree that anthropogenic noise pollution may negatively impact on conservation.

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TL;DR: In this paper, real-world vehicle operating mode data (2.5 million 1-Hz records) collected by instrumenting the vehicles of 82 volunteer drivers with OBD datalogger and GPS while they drove their routine travel routes, were analyzed to quantify vehicle emissions estimate errors due to road grade and driving style in rural, hilly Vermont.
Abstract: Real-world vehicle operating mode data (2.5 million 1 Hz records), collected by instrumenting the vehicles of 82 volunteer drivers with OBD datalogger and GPS while they drove their routine travel routes, were analyzed to quantify vehicle emissions estimate errors due to road grade and driving style in rural, hilly Vermont. Data were collected in winter and summer for MY 1996 and newer passenger cars and trucks only. EPA MOVES2010b was used to estimate running exhaust emissions associated with measured vehicle activity. Changes in vehicle specific power (VSP) and MOVES operating mode (OpMode) due to proper accounting for real-world road grade indicated emission rate errors between 10% and 48%, depending on pollutant, chiefly because grade-related changes in VSP could shift activity by as many as six OpModes, depending on road type. The correct MOVES OpMode assignment was made only 33–55% of the time when road grade was not included in the VSP calculation. Driving style of individual drivers was difficult to assess due to unknown traffic operations data, but the largest differences between individual drivers were observed on rural restricted roads, where traffic conditions and control have minimal impact. The results suggest the importance of (1) measuring and incorporating real-world road grade in order to correctly assign MOVES emission rates; and (2) developing a driving style typology to account for differences in the MOVES emissions estimates due to driver variability.

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TL;DR: In this paper, a trajectory-based energy/emissions estimation method is proposed for signalized arterials, which offers a cost-effective way to estimate fuel consumption and emissions for large areas.
Abstract: While fuel economy and global environment being increasingly recognized, it has become an imperative task to estimate vehicular fuel consumption and emissions for broad areas, including both freeway segments and signalized arterials. This task is much more challenging for signalized arterials compared with its counterpart on freeways, due to the disturbance brought by traffic signals and pedestrians. In this paper, a trajectory-based energy/emissions estimation method is proposed for signalized arterials, which offers a cost-effective way to estimate fuel consumption/emissions for large areas. Using mobile sensing data (e.g., GPS traces) collected from a sample of the traffic flow, the proposed method first estimates the trajectories for the entire traffic population, including free-flow vehicles and queued vehicles. The estimated trajectories reflect not only the traffic state (e.g., queuing and free-flowing), but also vehicle’s driving mode (e.g., cruise, idle, acceleration and deceleration). Vehicle-based fuel consumption/emissions are then estimated, using the Comprehensive Modal Emissions Model (CMEM), based on which the total vehicular fuel consumption and emissions of the entire traffic flow can be estimated. The proposed method is tested using real world field data (NGSIM) and micro-simulation data. The estimation results indicate that adding random noise to the cruise mode and using a state-dependent acceleration process lead to improved estimation results. The estimation errors of total fuel consumption and emissions are typically within 10–20%. The vehicle-based estimation results reveal that if the number of vehicles can be well estimated, the corresponding fuel/emission results are usually close to the ground truth values.

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TL;DR: In this article, the authors discuss the impact of three freight transport policies aiming to promote railroad intermodal transport in Europe, and examine the case of Belgium as a testing ground.
Abstract: This paper discusses the impact of three freight transport policies aiming to promote railroad intermodal transport in Europe, and examines the case of Belgium as a testing ground. These policies consist in subsidizing intermodal transport operations (such as in Belgium, to stimulate rail transport), internalizing external costs (as recommended by the European Union in order to foster cleaner modes), and adopting a system perspective when optimizing the location of inland intermodal terminals. The study proposes an innovative mixed integer intermodal freight location-allocation model based on hub-location theory and deals with non-linear transport costs in order to replicate economies of distance. Our analysis suggests that subsidizing has a significant impact on the volumes transported by intermodal transport, and, to a lesser extent, that optimizing terminal location increases the competitiveness of intermodal transport. On the other hand, according to our assumptions, internalizing external costs can negatively impact the promotion of intermodality. This finding indicates that innovative last-mile transports are needed in order to reduce the external impacts of drayage operations.