Showing papers in "Transportation Research Part D-transport and Environment in 2013"

Intent to purchase a plug-in electric vehicle: A survey of early impressions in large US cites

Abstract: This paper examines consumer stated intent to purchase plug-in electric vehicles and assesses the factors that increase or decrease interest. We surveyed adult drivers in large US cities in early fall 2011, before vehicle manufacturers and dealers began marketing campaigns. The survey responses thus document early impressions of this transport technology. We find that, given current battery technology and public perceptions, overall stated intent to purchase or lease electric vehicles is low. Interest in plug-in hybrid technology is somewhat greater than interest in all-electric technology. Consumers who express early interest in adopting electric vehicles are typically highly educated, previous owners of conventional hybrids, environmentally sensitive, and concerned about dependence on foreign oil. Enhanced fuel economy, the primary tangible advantage of plug-in technology, is recognized as favorable by respondents but fails to exert a strong influence on purchasing intentions. Interest in plug-in electric vehicles is shaped primarily by consumers’ perceptions of electric vehicle disadvantages.

On the stability of preferences and attitudes before and after experiencing an electric vehicle

Abstract: In this study, we investigate the extent to which experience affects individual preferences for specific electric vehicle characteristics, individual attitudes toward the environment, and the impact of the attitudes on the choice between an electric and a conventional vehicle. We use a two-wave stated preference experiment where data was collected before and after the respondents experienced an electric vehicle for three months. We estimate a hybrid choice model using jointly the stated choices before and after the test period. The results show that individual preferences change significantly after a real experience with an electric vehicle in the household. In particular, there are major changes in the preference for driving range, top speed, fuel cost, battery life and charging in city centres and train stations. In line with other studies, we find that environmental concern has a positive effect on the preference for EVs both before and after the test period, but the attitude itself and its effect on the choice of vehicle does not change.

Consumer preferences for alternative fuel vehicles: A discrete choice analysis

Abstract: This paper analyzes the potential demand for privately used alternative fuel vehicles using German stated preference discrete choice data. By applying a mixed logit model, we find that the most sensitive group for the adoption of alternative fuel vehicles embraces younger, well-educated, and environmentally aware car buyers, who have the possibility to plug-in their car at home, and undertake numerous urban trips. Moreover, many households are willing to pay considerable amounts for greater fuel economy and emission reduction, improved driving range and charging infrastructure, as well as for enjoying vehicle tax exemptions and free parking or bus lane access. The scenario results suggest that conventional vehicles will maintain their dominance in the market. Finally, an increase in the battery electric vehicles’ range to a level comparable with all other vehicles has the same impact as a multiple measures policy intervention package.

Simulation-Optimization Model for Location of a Public Electric Vehicle Charging Infrastructure

Abstract: The paper develops a simulation–optimization model that determines where to locate electric vehicle chargers to maximize their use by privately owned electric vehicles. Applying this model to the central-Ohio region, we demonstrate that a combination of level-one and -two chargers is preferable to level-two chargers only. We further explore interactions between the optimization criterion used and the budget available. We finally show that although the optimal location is sensitive to the specific optimization criterion considered, overall service levels are less sensitive to the optimization strategy.

Policy options to support the adoption of electric vehicles in the urban environment

Abstract: In this paper we discuss the effectiveness, efficiency and feasibility of policy measures that cities may adopt to stimulate the uptake and use of electric vehicles. Our analysis is based on an expert workshop in which municipal policy-makers used a group decision room system to exchange their experiences with electric vehicle related policies. We distinguish six categories of measures: supporting citizens and businesses, supporting charging-infrastructure build up, regulatory measures, raising awareness, government as lead user, and governing the transition with other levels of government. We find two feasible policy mixes of effective and efficient measures, one for cities that strive to be among the global frontrunners and one of no-regret policies that any city should adopt, if it wants to stimulate electric mobility.

Positive and negative spillover effects from electric car purchase to car use

Abstract: This study reports the results of two online surveys conducted on buyers of conventional combustion engine cars compared to those of electric vehicles in Norway. The results show that electric cars are generally purchased as additional cars, do not contribute to a decrease in annual mileage if the old car is not substituted, and that electric car buyers use the car more often for their everyday mobility. Psychological determinants derived from the theory of planned behavior and the norm-activation theory show a high correlation between the purchase and use stages. Electric car buyers, have lower scores on many determinants of car use, especially awareness of consequences and close determinants of car use.

Five years of London’s low emission zone: Effects on vehicle fleet composition and air quality

Abstract: This paper uses registration and enforcement information to assess the impact of London’s low emission zone on vehicle registrations, usage and air pollution. The zone was implemented in a staged process in 2008 to reduce the emissions of air pollutants of direct harm to human health. The zone targeted the worst polluters, specifically heavy diesel vehicles, buses and coaches by imposing minimum emissions standards on vehicles operating in an area covering most of Greater London. Several years on it remains unclear how successful the zone has been in meeting its stated objectives and what improvements in pollution levels can be attributed to the low emission zone. Results presented in this paper suggest the rate of fleet turnover for affected vehicle classes in London increased substantially when the zone was first introduced before returning to the national average in subsequent years. Early evidence for light commercial vehicles, which became subject to the scheme in early 2012, shows a similar effect is likely. Despite an overall growth in freight vehicles operating in London, the number of pre-Euro III vehicles has dropped and this has been coupled with a switch from rigid vehicles to light commercial vehicles and articulated vehicles. Ambient air quality measurements show concentrations of particulate matter within the low emission zone have dropped by 2.46–3.07% compared to just over 1% for areas just outside the zone. However, no discernible differences are found for NOX concentrations.

A census of the US near-roadway population: Public health and environmental justice considerations

Abstract: This study estimates the size and distribution of the population living near high volume roads in the US, investigates race and income disparities in these near roadway populations, and considers the coverage of the national ambient air quality monitoring network. Every US census block is classified by traffic density and proximity to roads falling within several traffic volume ranges using year 2008 traffic data and the 2010 and 2000 US Census. The results indicate that 19% of the population lives near high volume roads. Nationally, greater traffic volume and density are associated with larger shares of non-white residents and lower median household incomes. Analysis at the county level finds wide variation in the size of near roadway populations and the severity of environmental justice concerns. Every state, however, has some population living near a high volume road and 84% of counties show some level of disparity. The results also suggest that most counties with residents living near high volume roads do not have a co-located regulatory air quality monitor.

Trajectory optimization for eco-driving taking into account traffic constraints

Abstract: In this work potential gains in fuel consumption due to eco-driving will be discussed. A vehicle model and numerical optimization methods are used to identify optimal vehicle operation. To advice the driver of the realistically optimal velocity trajectory for a given trip, road and traffic constraints have to be taken into account. Most prior work on eco-driving do not consider traffic constraints. In this study, however, the chosen optimization method allows us to integrate traffic constraints in the form of a vehicle following situation. Three different factors specifying safe vehicle following are introduced and their influence on fuel consumption is discussed. With the results the gains of eco-driving are identified, while comparing a traffic-restricted situation with the overall optimal, non-constrained, vehicle operation.

Heterogeneous fixed fleet vehicle routing considering carbon emission

Abstract: The paper considers heterogeneous fixed fleet vehicle routing with carbon emission to minimizing the sum of variable operation costs. A cost-benefit assessment of the value of purchasing or selling of carbon emission rights, using a mixed integer-programming model to reflect heterogeneous vehicle routing, is incorporated. Essentially, the use of a carbon market as a means of introducing more flexibility into an environmentally constrained network is considered. Tabu search algorithms are used to obtain solutions within a reasonable amount of computation time. In particular, we show the possibility that the amount of carbon emission can be reduced significantly without sacrificing the cost due to the benefit obtained from carbon trading.

Comparative analysis of the safety effects of electric bikes at signalized intersections

Abstract: The paper compares the risk-taking behavior of the riders of electric-bikes and bicycles and their effects on safety at signalized intersections. Data were collected at signalized intersections in the city of Kunming in China. Traffic conflicts techniques are used to estimate the safety effects of electric-bikes and bicycles, with the incidents observed divided into sixteen types. About 77.7% of conflicts were caused by the risky behavior of the automobiles drivers that in particular did not yield right-of-way to electric-bikes/bicycles, 13.4% by the risky behavior of e-bikers, and the rest by cyclists. Red-light running was the leading cause for the conflicts in which the electric-bikes were at-fault.

Willingness-to-pay for infrastructure investments for alternative fuel vehicles

Abstract: This study investigates potential demand for infrastructure investment for alternative fuel vehicles by applying stated preference methods to a Japanese sample. The potential demand is estimated on the basis of how much people are willing to pay for alternative fuel vehicles under various refueling scenarios. Using the estimated parameters, the economic efficiency of establishing battery-exchange stations for electric vehicles is examined. The results indicate that infrastructural development of battery-exchange stations can be efficient when electric vehicle sales exceed 5.63% of all new vehicle sales. Further, we find a complementary relationship between the cruising ranges of alternative fuel vehicles and the infrastructure established.

Rapid estimation of global civil aviation emissions with uncertainty quantification

Abstract: In this paper we describe the methods used to develop the open source Aviation Emissions Inventory Code and produce a global emissions inventory for scheduled civil aviation, with quantified uncertainty. We estimate that in 2005, scheduled civil aviation was responsible for 180.6 Tg of fuel burn, which agrees to within 4% of other published emissions inventories for 2004 and 2006. By comparing the Aviation Emissions Inventory Code with flight data records, we show that the mean bias in predicted fuel burn at the airport-pair level is +1% for an ensemble of 132 flights, and less than 10% for 5 of the 6 aircraft types used in the validation.

Understanding adolescents' intentions to commute by car or bicycle as adults

Abstract: This study focuses on the intentions of adolescents to commute by car or bicycle as adults. The behavioral model is based on intrapersonal and interpersonal constructs from the theory of planned behavior extended to include constructs from the institutional, community and policy domains. Data from a survey among Danish adolescents is analyzed. It is found that car use intentions are related to positive car passenger experience, general interest in cars, and car ownership norms, and are negatively related to willingness to accept car restrictions and perceived lack of behavioral control. Cycling intentions are related to positive cycling experience, willingness to accept car restrictions, negative attitudes towards cars, and bicycle-oriented future vision, and are negatively related to car ownership norms. Attitudinal constructs are related to individual characteristics, such as gender, residential location, current mode choice to daily activities, and parental travel patterns.

Network-wide impacts of eco-routing strategies: A large-scale case study

Abstract: This paper quantifies the system-wide impacts of implementing a dynamic eco-routing system, considering various levels of market penetration and levels of congestion in downtown Cleveland and Columbus, Ohio, USA. The study concludes that eco-routing systems can reduce network-wide fuel consumption and emission levels in most cases; the fuel savings over the networks range between 3.3% and 9.3% when compared to typical travel time minimization routing strategies. We demonstrate that the fuel savings achieved through eco-routing systems are sensitive to the network configuration and level of market penetration of the eco-routing system. The results also demonstrate that an eco-routing system typically reduces vehicle travel distance but not necessarily travel time. We also demonstrate that the configuration of the transportation network is a significant factor in defining the benefits of eco-routing systems. Specifically, eco-routing systems appear to produce larger fuel savings on grid networks compared to freeway corridor networks. The study also demonstrates that different vehicle types produce similar trends with regard to eco-routing strategies. Finally, the system-wide benefits of eco-routing generally increase with an increase in the level of the market penetration of the system.

Comparative pavement life cycle assessment with parameter uncertainty

Abstract: We present a comparative life cycle assessment of pavements considering measurement uncertainty and the data-quality uncertainty. We account for the uncertainty due to the prediction of roughness over pavement lifetime and propagate the consequence into the overall footprint. The uncertainty propagation is conducted using a Monte Carlo simulation. Making use of a comparison indicator, the difference in the environmental impacts of two alternative designs is statistically characterized taking into account the correlation in the input parameters. The contribution of different phases and their associated uncertainty characterized and compared for two pavements.

A multi-objective optimization model for sustainable logistics facility location

Abstract: This paper offers an exploratory study of sustainable facility location. The methodology, based on the classical uncapacitated facility location problem, provides decision makers with a multi-objective optimization model to determine the trade-off among economic, service and environmental considerations. Our results indicate that it may be desirable to open more facilities than optimal from a narrow economic perspective to reduce the carbon dioxide emissions of transport and to improve service reliability.

Estimating near-road pollutant dispersion: A model inter-comparison

Abstract: A model inter-comparison study to assess the abilities of steady-state Gaussian dispersion models to capture near-road pollutant dispersion has been carried out with four models (AERMOD, run with both the area-source and volume-source options to represent roadways, CALINE, versions 3 and 4, ADMS and RLINE). Two field tracer studies are used: the Idaho Falls tracer study and the Caltrans Highway 99 tracer study. Model performance measures are calculated using concentrations (observed and estimated) that are paired in time and space, since many of the health related questions involve outcomes associated with spatially and temporally distributed human activities. All four models showed an ability to estimate the majority of downwind concentrations within a factor of two of the observations. RLINE, AERMOD-V, and ADMS, also have the capability to predict concentrations upwind of the roadway that result from low-speed meandering of the plume. Generally, RLINE, ADMS, and AERMOD (both source types) had overall performance statistics that were broadly similar, while CALINE 3 and 4 both produced a larger degree of scatter in their concentration estimates. The models performed best for near-neutral conditions in both tracer studies, but had mixed results under convective and stable conditions.

Estimating the CO2 intensity of intermodal freight transportation

Abstract: This paper looks at the environmental effects of shifting from road to rail freight transportation. Little data is available to shippers to calculate the potential CO 2 savings of an intermodal shift. In this paper we analyze a data set of more than 400,000 intermodal shipments to calculate the CO 2 intensity of intermodal transportation as a distinct mode. Our results indicate an average intensity of 67 g of CO 2 per ton-mile, but can vary between 29 and 220 g of CO 2 per ton-mile depending on the specific origin–destination lane. We apply the market area concept to explain the variance between individual lane intensities and demonstrate the complexity in predicting the potential carbon savings in a switch from truckload to intermodal.

Comparative effects of eco-driving initiatives aimed at urban bus drivers - Results from a field trial

Abstract: A field trial is used to investigate effects of two programmes aimed at encouraging bus drivers to develop and maintain ecological driving behaviour. Drivers on one bus line were divided into three groups, one received feedback from an in-vehicle system, the second received the same feedback coupled with personal training sessions, and the third acting as a control. A 6.8% fuel saving and large decreases in instances of harsh deceleration and speeding were found, but with no difference in the effect of the two eco-driving strategies. The drivers reported perceived gains in theoretical knowledge of eco-driving, but found it more difficult to put that knowledge into practice. Several contextual factors were found to limit drivers’ to eco-driving, most noticeably shaped by their work tasks, but also the commitment of the company where they were employed.

Ships in a city harbour: An economic valuation of atmospheric emissions

Abstract: This paper examines the emissions from ships at berth in the Port of Bergen in Norway. As well as estimating the quantity of emissions, we look at estimates of the external costs of pollution and derive a cost for the pollutants emitted by the ships at berth in Bergen. The cost of these emissions is estimated at between €10 m and €21.5 m per year.

Environmental correlates of cycling: Evaluating urban form and location effects based on Danish micro-data

Abstract: The paper analyses the environmental correlates of cycling based on Danish transportation and urban form micro-data. The results show that established walkability factors such as density, connectivity and diversity are related to cycling, but access to retail concentrations/centres, public transportation level-of-service, as well as competition between walking and cycling depending on environmental features can be added. Attractive conditions for using public transportation or walking are related to less cycling. The findings quantify the effects of urban form on the probability of cycling and the distance cycled. A high probability of cycling generally implies short cycling distances leading to non-uniform, non-monotonous relationship between environmental indicators such as walkability and cycling.

Accommodating underlying pro-environmental attitudes in a rail travel context: Application of a latent variable latent class specification

Abstract: Using data from a stated preference survey conducted in the UK, we show how the relative importance that rail travellers attach to reductions in greenhouse gas emissions and faster journey times varies strongly as a function of underlying attitudes towards the environment. We specify a latent class structure that allocates respondents to two classes with substantially different valuations of greenhouse gas emissions, and show how the allocation of a given respondent to either class is a function of underlying attitudes that also drive the answers to a number of attitudinal questions. We also show how these underlying attitudes are a function of a number of socio-demographic characteristics, with female respondents, older respondents, and respondents with a university degree having a stronger pro-environmental attitude, with the opposite applying to respondents with regular car access.

Assessing greenhouse gas emissions from port vessel operations at the Port of Incheon

Abstract: This paper measures greenhouse gas emissions from port vessel operations by considering the case of Korea’s Port of Incheon. It provides estimates of greenhouse gas emissions based on the type and the movement of a vessel from the moment of its arrival, to its docking, cargo handling, and departure. Taking a bottom-up approach based on individual vessels’ characteristics and using data on vessels processed by the port in 2012 estimate emissions. The results indicate that the level of emissions is five times higher than that estimated through the top-down approach. Among various types of vessels, international car ferries are the heaviest emitters, followed by full container vessels and car carriers. A vessel’s passage through lock gates and maneuver to approach the dock accounts for 96% of its emissions. Docking for cargo handling shows the lowest level of GHG emissions.

Analysis of the operational energy efficiency for inland river ships

Abstract: This paper looks at the energy consumption and green house gas emissions of inland river shipping, and compares them with the performance of seagoing ships. The analysis is based on a case study of container shipping on the Yangtze River, China. Data were collected under both calm water and real navigation conditions, and energy efficiency operation indices under these conditions are calculated and analyzed. We find that the navigation environment can influence significantly the operational energy efficiency of inland river ships.

US residential charging potential for electric vehicles

Abstract: We assess existing and potential charging infrastructure for plug-in vehicles in US households using data from the American Housing Survey and the Residential Energy Consumption Survey. We estimate that less than half of US vehicles have reliable access to a dedicated off-street parking space at an owned residence where charging infrastructure could be installed. Specifically, while approximately 79% households have off-street parking for at least some of their vehicles, only an estimated 56% of vehicles have a dedicated off-street parking space – and only 47% at an owned residence. Approximately 22% vehicles currently have access to a dedicated home parking space within reach of an outlet sufficient to recharge a small plug-in vehicle battery pack overnight. Access to faster charging, required for vehicles with longer electric range, will usually require infrastructure investment ranging from several hundred to several thousand dollars, depending on panel and construction requirements. We discuss sensitivity of results to uncertain factors and implications for the potential of mainstream penetration of plug-in vehicles.

VISSIM/MOVES integration to investigate the effect of major key parameters on CO2 emissions

Abstract: This paper looks at CO2 emissions on limited access highways in a microscopic and stochastic environment using an optimal design approach. Estimating vehicle emissions based on second-by-second vehicle operation allows the integration of a microscopic traffic simulation model with the latest US Environmental Protection Agency’s mobile source emissions model to improve accuracy. A factorial experiment on a test bed prototype of the I-4 urban limited access highway corridor located in Orlando, Florida was conducted to identify the optimal settings for CO2 emissions reduction and to develop a microscopic transportation emission prediction model. An exponentially decaying function towards a limiting value expressed in the freeway capacity is found to correlate with CO2 emission rates. Moreover, speeds between 55 and 60 mph show emission rate reduction effect while maintaining up to 90% of the freeway’s capacity. The results show that speed has a significant impact on CO2 emissions when detailed and microscopic analysis of vehicle operations of acceleration and deceleration are considered.

Reducing emissions through speed optimization in supply vessel operations

Abstract: This paper examines how optimizing sailing speeds can reduce supply vessels emissions in the upstream supply chain to offshore installations. We introduce several speed optimization strategies to be used in construction of periodic vessel schedules. The strategies consider vessel waiting times before the start of service at installations and at supply base. Tests carried out on real instances from Statoil’s activities on the Norwegian continental shelf indicate that a 25% emissions and fuel cost reductions can be achieved without fleet size increase.

Eco-driver training within the City of Calgary’s municipal fleet: Monitoring the impact

Abstract: This article highlights eco-driving as an available policy option to reduce climate altering GHG emissions. Recognizing the need to reduce the environmental impact of its fleet operations, the City of Calgary is a leader in developing programs and policies that aim to reduce GHG emissions and associated pollutants resulting from the use of fossil fuels. Among local action taken against climate change, the City sought to quantify CO2 emissions reductions from their municipal fleet as a result of eco-driver training, with a specific focus on engine idling. Fifteen drivers from the Development & Building Approvals Business Unit had in-vehicle monitoring technology (CarChips®) installed into their vehicles as part of a three-phase research process. The results show that gasoline and hybrid vehicles decreased average idling between 4% and 10% per vehicle per day, leading to an average emissions decrease of 1.7 kg of CO2 per vehicle per day.

Consumer purchase intentions for flexible-fuel and hybrid-electric vehicles

Abstract: This study explores the factors that influence consumer likelihood of purchasing two different types of alternative-fuel vehicles - flexible fuel and hybrid-electric. Data for the study come from an online survey of US automobile owners. Results suggest that concerns about energy security, the environment, and the availability of alternative fuels, along with demographic factors, have significant effects on consumer purchase expectations for alternative-fuel vehicles.