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1.
Electric Freight Vehicles (EFVs) are a promising and increasingly popular alternative to conventional trucks in urban pickup/delivery operations. A key concerned research topic is to develop trip-based Tank-to-Wheel (TTW) analyses/models for EFVs energy consumption: notably, there are just a few studies in this area. Leveraging an earlier research on passenger electric vehicles, this paper aims at filling this gap by proposing a microscopic backward highly-resolved power-based EFVs energy consumption model (EFVs-ECM). The model is estimated and validated against real-world data, collected on a fleet of five EFVs in the city centre of Rome, for a total of 144 observed trips between subsequent pickup/delivery stops. Different model specifications are tested and contrasted, with promising results, in line with previous findings on electric passenger vehicles. 相似文献
2.
Recently, the use of more sustainable forms of transportation such as electric vehicles (EVs) for delivering goods and parcels to customers in urban areas has received more attention from urban planners and private stakeholders. To provide some insights toward the use of EVs, this work develops an optimization framework using portfolio theory, which takes into account the cost and the risks associated with some input parameter uncertainties, for determining an optimal combination of EVs with internal combustion engine vehicles (ICEVs) in urban freight transportation (UFT) over some planning time period. This model can assist an urban freight operator to choose the best investment strategy for introducing new vehicles into its fleet while gaining economic benefits and having positive impacts on the urban environment. When taking into account the risks that are involved, the numerical results show that EVs have the potential to compete with ICEVs in UFT. 相似文献
3.
Parcel carriers face increasingly difficult operating conditions in busy metropolitan areas due to growing consumer demand for ever faster delivery services and having to cope with traffic congestion and city authority measures that may restrict or penalise access for certain types of vehicle. This paper evaluates the potential environmental and financial benefits of switching from traditional van-based deliveries to an alternative operating model, where porters or cycle couriers undertake deliveries supported by a substantially reduced van fleet.Results using a specially-developed algorithm to model operations of a real carrier in an area of central London, UK, suggested that the carrier could reduce CO2 emissions by 45%, NOx emissions by 33%, driving distance by 78% and curbside parking time by 45%. Overall cost savings to the carrier were estimated to be in the range 34–39%. Scaling up the modelled emissions savings to London’s Central Activities Zone, an area of approximately 30 km2 and with current total annual parcel delivery distance of around 15 million km, could see annual emissions savings in the region of 2 million kg CO2 and 1633 kg NOx if all carriers utilised porters or cycle couriers. The key operating challenges identified were related to sorting and consolidating items by weight and volume, parcel handover arrangements and how to deal with express items and failed deliveries. 相似文献
4.
Reducing the empty weight of articulated heavy goods vehicle trailers is one avenue that needs to be explored in reducing the carbon footprint of the road freight industry as a whole. A statistical analysis of two heavy goods vehicle fleets operating in the United Kingdom has helped to identify double-deck trailers used in grocery haulage and ‘walking-floor’ trailers used in bulk haulage as two examples of trailers that can benefit significantly from lightweighting. Energy consumption of numerous articulated heavy goods vehicles is quantified through an idealised drive cycle analysis reflecting a long haul journey over a highway. This energy analysis allows for a mass energy performance index to be established. The analysis has shown that reducing the empty weight of trailers by 30% can cause reductions of up to 18% and 11% in mass energy performance index for double-deck trailers and ‘walking-floor’ trailers respectively. Using this approach, trailers that will benefit the most from weight reduction can be identified systematically, allowing for lightweighting strategies to be implemented more effectively. Strategies to reduce empty trailer weight and improve vehicle utilisation are also discussed. 相似文献
5.
This paper reports the results of a stated-preference study aimed at investigating how transport decisions are made by receivers
or by transport operators about the potential use of an urban freight consolidation centre in the city of Fano, Italy. Because
there are no revealed preference data, a stated-choice methodology is used. The stated-choice experiments present two alternatives—one
using a private vehicle subject to various traffic regulations and one using the urban freight consolidation centre with varying
cost and efficiency levels. Conventional discrete choice data modelling shows that the potential demand is influenced mainly
by the distance of the parking bay from the shop, by access permit cost, by the service cost of the urban freight consolidation
centre, and by the delay in delivery time. Simulations are then performed to assess how the potential demand is affected by
various incentives and regulations affecting urban goods distribution.
Edoardo Marcucci is Associate Professor of Applied Economics at the Faculty of Political Sciences, University of Roma Tre, Italy, General Secretary of the Italian Society of Transportation Economists, and co-founder of the Kuhmo—Nectar Conference and Summer School Series on Pricing, Financing, Regulating Transport Infrastructures and Services. He has studied freight transportation concentrating on interactions along logistic supply chains. Romeo Danielis is Full Professor at the University of Trieste, Italy. He is managing editor of European Transport\Trasporti Europei. He has published articles on input-output modelling, regional environmental policy, social costing of transport externalities, EU enlargement and on several transport issues including road pricing, the Down-Thompson paradox, energy use and CO2 emissions, freight transport demand and stated preferences. 相似文献
| Edoardo MarcucciEmail: |
Edoardo Marcucci is Associate Professor of Applied Economics at the Faculty of Political Sciences, University of Roma Tre, Italy, General Secretary of the Italian Society of Transportation Economists, and co-founder of the Kuhmo—Nectar Conference and Summer School Series on Pricing, Financing, Regulating Transport Infrastructures and Services. He has studied freight transportation concentrating on interactions along logistic supply chains. Romeo Danielis is Full Professor at the University of Trieste, Italy. He is managing editor of European Transport\Trasporti Europei. He has published articles on input-output modelling, regional environmental policy, social costing of transport externalities, EU enlargement and on several transport issues including road pricing, the Down-Thompson paradox, energy use and CO2 emissions, freight transport demand and stated preferences. 相似文献
6.
Electric freight vehicles have the potential to mitigate local urban road freight transport emissions, but their numbers are still insignificant. Logistics companies often consider electric vehicles as too costly compared to vehicles powered by combustion engines. Research within the body of the current literature suggests that increasing the driven mileage can enhance the competitiveness of electric freight vehicles. In this paper we develop a numeric simulation approach to analyze the cost-optimal balance between a high utilization of medium-duty electric vehicles – which often have low operational costs – and the common requirement that their batteries will need expensive replacements. Our work relies on empirical findings of the real-world energy consumption from a large German field test with medium-duty electric vehicles. Our results suggest that increasing the range to the technical maximum by intermediate (quick) charging and multi-shift usage is not the most cost-efficient strategy in every case. A low daily mileage is more cost-efficient at high energy prices or consumptions, relative to diesel prices or consumptions, or if the battery is not safeguarded by a long warranty. In practical applications our model may help companies to choose the most suitable electric vehicle for the application purpose or the optimal trip length from a given set of options. For policymakers, our analysis provides insights on the relevant parameters that may either reduce the cost gap at lower daily mileages, or increase the utilization of medium-duty electric vehicles, in order to abate the negative impact of urban road freight transport on the environment. 相似文献
7.
We propose the vehicle routing problem with roaming delivery locations (VRPRDL) to model an innovation in last-mile delivery where a customer’s order is delivered to the trunk of his car. We develop construction and improvement heuristics for the VRPRDL based on two problem-specific techniques: (1) efficiently optimizing the delivery locations for a fixed customer delivery sequence and (2) efficiently switching a predecessor’s or successor’s delivery location during the insertion or deletion of a customer in a route. Furthermore, we conduct an extensive computation study to assess and quantify the benefits of trunk delivery in a variety of settings. The study reveals that a significant reduction in total distance travelled can be achieved, especially when trunk delivery is combined with traditional home delivery, which has both economic and environmental benefits. 相似文献
8.
This paper introduces a model of urban freight demand that seeks to estimate tour flows from secondary data sources e.g., traffic counts, to bypass the need for expensive surveys. The model discussed in this paper, referred as Freight Tour Synthesis (FTS), enhances current techniques by incorporating the time-dependent tour-based behavior of freight vehicles, and the decision maker’s (e.g., metropolitan planning agency planner) preferences for different sources of information. The model, based on entropy maximization theory, estimates the most likely set of tour flows, given a set of freight trip generation estimates, a set of traffic counts per time interval, and total freight transportation cost in the network. The type of inputs used allows the assessment of changes in infrastructure, policy and land use. The ability of the model to replicate actual values is assessed using the Denver Region (CO) as a case study. 相似文献
9.
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. 相似文献
10.
This paper investigates transport providers’ preferences for alternative loading bays and pricing policies. It estimates the importance of loading bays, the probability of finding them free and offers strategically relevant information to policy makers. The results underline the relevance of both preference heterogeneity and non-linear attribute effects. Three classes of agents are detected with substantially different preferences also characterized by non-linear sensitivity to attribute level variations. The specific freight sector, frequency of accesses and number of employees are all relevant covariates explaining different preferences for alternative transport providers’ categories. The implications of the results obtained are illustrated by simulating alternative policy scenarios. In conclusion, the paper underlines the need for rigorous policy analysis if the correct policy outcomes are to be estimated with an adequate level of accuracy. 相似文献
11.
P. K. Else 《运输规划与技术》2013,36(4):295-300
This paper extends the discussion of certain problems associated with road pricing raised in an earlier contribution to this journal. Firstly it is shown that where the value of time varies between different groups of traffic using the same congested road, optimal road pricing requires price discrimination between the groups such that those with the lowest value of time pay the highest charge and suffer the greatest losses. However, a uniform price based on an “equity” value of time would reduce the relative distributional effects. Secondly the paper takes up the suggestion that queueing (and by extension congestion) may be positively helpful in the allocation of resources and shows that this is not in general correct although there are situations in which the use of queueing alongside conventional pricing may have a role to play. Finally it is argued that governments’ apparent lack of enthusiasm for road pricing stems as much from political considerations as the more technical problems of applying it. 相似文献
12.
13.
R. Smith M. Morison D. Capelle C. Christie D. Blair 《Transportation Research Part D: Transport and Environment》2011,16(8):614-618
Using the WPG03 duty cycle developed from global positioning data collected in Winnipeg, Canada, real world energy demands and costs are modeled. Three types of plug-in hybrid electric vehicles, four temperatures and two charging scenarios are compared to a vehicle with an internal combustion engine. Cold temperatures are shown to greatly affect vehicle operation energy costs, which is an important consideration for cold weather cities such as Winnipeg. The largest energy cost savings are obtained for smaller-battery plug-in hybrids that had the opportunity to charge during the day. 相似文献
14.
Mobile communication instruments have made detecting traffic incidents possible by using floating traffic data. This paper studies the properties of traffic flow dynamics during incidents and proposes incident detection methods using floating data collected by probe vehicles equipped with on-board global positioning system (GPS) equipment. The proposed algorithms predict the time and location of traffic congestion caused by an incident. The detection rate and false rate of the models are examined using a traffic flow simulator, and the performance measures of the proposed methods are compared with those of previous methods. 相似文献
15.
This study analyzes the preference structure of buyer groups that influences their willingness to select CO2-saving power train technologies for medium-duty and heavy-duty vehicles (HDV). Based on the Technology–Organization–Environment framework for organizational adoption decision making and organizational buying criteria a theoretical construct was developed. Variables were validated in exploratory preliminary research and subsequently tested based on factor analysis using 27 survey items in a quantitative web-based study among 177 organizations operating HDV in Germany. Knowledge, experience, use and purchase consideration concerning alternative power train technologies and further measures to reduce fuel consumption were additionally queried. Based on a multiple linear regression analysis, key findings show that at the current stage of market maturity environmental attitude and corporate social responsibility exert the strongest significant influence on willingness to select CO2-saving power train technologies. A hierarchical cluster analysis revealed six customer groups in order to yield behavioral market segmentation. Hereby it is shown that the performed transportation tasks do not determine the preference structures. Early adopting organizations are larger than average and driven by non-economic aspects as image or corporate social responsibility, whereas the mass market awaits lower purchasing prices. Crossing this chasm will be a major challenge for policymaker and manufacturers. 相似文献
16.
There is considerable evidence that roundabouts are the safest and most efficient form of traffic control for most intersections. The potential use of roundabouts with all their inherent benefits may be greatly diminished if they are not able to accommodate oversize/overweight (OSOW) vehicles, sometimes called “Superloads.” The problem, therefore, is how to accommodate OSOW vehicles without sacrificing the integrity, safety and other benefits of roundabouts.This study uses TORUS software to design six standard roundabouts using guidance from the latest Federal Highway Administration (FHWA) roundabout guide. Six OSOW check vehicles from the Wisconsin Department of Transportation’s library were used to modify the designs to accommodate these selected check vehicles at the roundabouts. These six OSOW check vehicles were used to conduct swept path analysis using AutoTURN software at the selected six standard roundabouts for right turn, through, and left turn simulations. The space requirements for these maneuvers were analyzed in detail. Various strategies for better accommodating these OSOW check vehicles were suggested and experimented with in this study using AutoTURN software simulations. The effectiveness of using a straight passage through the center island for OSOW vehicles was also addressed in this study and was found to be effective. All the strategies investigated in this study proved to be effective in accommodating OSOW vehicles when compared to conventional ways of using a roundabout. The needed total truck apron was calculated and used as a reference to determine an effective strategy for accommodating OSOW vehicles. This research can be used as guidance for transportation engineers, planners and decision makers to determine possible ways of designing a roundabout at an intersection where certain OSOW vehicles are expected. 相似文献
17.
Conceptually, a Green Light Optimal Speed Advisory (GLOSA) system suggests speeds to vehicles, allowing them to pass through an intersection during the green interval. In previous papers, a single speed is computed for each vehicle in a range between acceptable minimum and maximum values (for example between standstill and the speed limit). This speed is assumed to be constant until the beginning of the green interval, and sent as advice to the vehicle. The goal is to optimise for a particular objective, whether it be minimisation of emissions (for environmental reasons), fuel usage or delay. This paper generalises the advice given to a vehicle, by optimising for delay over the entire trajectory instead of suggesting an individual speed, regardless of initial conditions – time until green, distance to intersection and initial speed. This may require multiple acceleration manoeuvres, so the advice is sent as a suggested acceleration at each time step. Such advice also takes into account a suitable safety constraint, ensuring that vehicles are always able to stop before the intersection during a red interval, thus safeguarding against last-minute signal control schedule changes. While the algorithms developed primarily minimise delay, they also help to reduce fuel usage and emissions by conserving kinetic energy. Since vehicles travel in platoons, the effectiveness of a GLOSA system is heavily reliant on correctly identifying the leading vehicle that is the first to be given trajectory advice for each cycle. Vehicles naturally form a platoon behind this leading vehicle. A time loop technique is proposed which allows accurate identification of the leader even when there are complex interactions between preceding vehicles. The developed algorithms are ideal for connected autonomous vehicle environments, because computer control allows vehicles’ trajectories to be managed with greater accuracy and ease. However, the advice algorithms can also be used in conjunction with manual control provided Vehicle-to-Infrastructure (V2I) communication is available. 相似文献
18.
This paper presents a research on traffic modelling developed for assessing traffic and energy performance of electric systems installed along roads for dynamic charging-while-driving (CWD) of fully electric vehicles (FEVs).The logic adopted by the developed traffic model is derived from a particular simulation scenario of electric charging: a freight distribution service operated using medium-sized vans. In this case, the CWD service is used to recover the state of charge of the FEV batteries to shortly start with further activities after arrival at the depot.The CWD system is assumed to be implemented in a multilane ring road with several intermediate on-ramp entrances, where the slowest lane is reserved for the dynamic charging of authorized electric vehicles. A specific traffic model is developed and implemented based on a mesoscopic approach, where energy requirements and charging opportunities affect driving and traffic behaviours. Overtaking manoeuvres as well as new entries in the CWD lane of vehicles that need to charge are modelled according to a cooperative driving system, which manages adequate time gaps between consecutive vehicles. Finally, a speed control strategy is simulated at a defined node to create an empty time-space slot in the CWD lane, by delaying the arriving vehicles. This simulated control, implemented to allow maintenance operations for CWD that may require clearing a charging zone for a short time slot, could also be applied to facilitate on-ramp merging manoeuvres. 相似文献
19.
It is often argued that driverless vehicles will save lives. In this paper, we treat the ethical case for driverless vehicles seriously and show that it has radical implications for the future of transport. After briefly discussing the current state of driverless vehicle technology, we suggest that systems that rely upon human supervision are likely to be dangerous when used by ordinary people in real-world driving conditions and are unlikely to satisfy the desires of consumers. We then argue that the invention of fully autonomous vehicles that pose a lower risk to third parties than human drivers will establish a compelling case against the moral permissibility of manual driving. As long as driverless vehicles aren’t safer than human drivers, it will be unethical to sell them. Once they are safer than human drivers when it comes to risks to 3rd parties, then it should be illegal to drive them: at that point human drivers will be the moral equivalent of drunk robots. We also describe two plausible mechanisms whereby this ethical argument may generate political pressure to have it reflected in legislation. Freeing people from the necessity of driving, though, will transform the relationship people have with their cars, which will in turn open up new possibilities for the transport uses of the automobile. The ethical challenge posed by driverless vehicles for transport policy is therefore to ensure that the most socially and environmentally beneficial of these possibilities is realised. We highlight several key policy choices that will determine how likely it is that this challenge will be met. 相似文献
20.
ObjectivesEvidence concerning crash risk for older heavy vehicle drivers is sparse, making it difficult to assess if it is prudent to encourage older drivers to remain in the workforce in a climate of labour shortages. The objective of this study was to estimate annual crash rate ratios of older male heavy vehicle drivers relative to their middle aged peers.MethodsData utilized in this study includes all crashes meeting inclusion criteria involving heavy goods vehicles, categorised as rigid trucks and articulated trucks; this data was recorded by the New South Wales Roads and Traffic Authority. The exposure to the risk of a crash was represented by distance travelled for each vehicle type and year, by age of driver, as estimated by the Australian Survey of Motor Vehicle Use. Negative binomial regression modelling was applied to estimate annual crash incidence rate ratios for male drivers in various age groups.ResultsA total of 26,146 crashes occurred in New South Wales during 1999–2006, involving a total of 54,191 vehicles; removing observations that did not meet the inclusion criteria, 19,736 observations remained representing 12,501 crashes. For rigid trucks, the incidence rate ratio for drivers aged 65+ years, compared to 45–54 year olds, was 0.74 (95% CI 0.51, 0.98). For articulated trucks, the annual crash incidence rate ratio for drivers aged 65+ years compared to 45–54 year olds was 1.4 (95% CI 0.96, 1.9), and that for drivers aged 55–64 years compared to 45–54 year olds was 1.1 (95% CI 0.83, 1.3).ConclusionsOlder male professional drivers of heavy goods vehicles have lower risk of crashes in rigid vehicles, possibly due to accrued driving experience and self-selection of healthy individuals remaining in the workforce. Thus, encouraging these drivers to remain in the workforce is appropriate in the climate of labour shortages, as this study provides evidence that to do so would not endanger road safety. 相似文献