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1.
One of the biggest unresolved problems regarding the completion of the free internal transport market within the European community is the problem of harmonization of taxation on the road haulage industry. As the highest tax country, Britain might be expected to have to reduce its level of taxes as part of any harmonization. This paper considers the current methodology of the British Department of Transport regarding the allocation of the track and external costs of road transport, in the light of developments in methodology and experience elsewhere in Western Europe and North America. We find a number of reasons for believing that, far from overstating the marginal social cost of use of roads by the road haulage industry, the current British approach actually understates it. Thus any move towards harmonizing tax levels may reduce taxes in Britain at a time when they should be increasing. 相似文献
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文章研究了重型商用车辆分别采用推荐道路阻力与实测道路阻力对在底盘测功机上进行整车油耗试验的结果差异。结果表明,采用推荐道路阻力不能真实反应出车辆的油耗水平;底盘测功机的阻力设定直接影响车辆的油耗结果,阻力设定值越大,油耗越大,反之越小。 相似文献
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《Transportation Research Part A: Policy and Practice》2006,40(5):444-457
This paper presents the results of a series of mixed logit models focusing on the distribution of the values of travel time savings. The parametric assumptions include both normal and various bounded distributions derived from the normal (log-normal, Johnson’s Sb and a censored normal). The full model, which also incorporates a number of time budget related variables, indicates that a small, but relevant share of the respondents might not value time savings, or would rather extend the journey. This share is consistent with results from other studies. A series of models for the different types of tours indicate even higher potential shares in situations with typically fewer binding time constraints.The RP data used is derived from the six week travel diary Mobidrive. The observations from Karlsruhe are summarised at the level of the tour. 相似文献
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Several industry leaders and governmental agencies are currently investigating the use of Unmanned Aerial Vehicles (UAVs), or ‘drones’ as commonly known, for an ever-growing number of applications from blue light services to parcel delivery. For the specific case of the delivery sector, drones can alleviate road space usage and also lead to reductions in CO2 and air pollution emissions, compared to traditional diesel-powered vehicles. However, due to their unconventional acoustic characteristics and operational manoeuvres, it is uncertain how communities will respond to drone operations. Noise has been suggested as a major barrier to public acceptance of drone operations in urban areas. In this paper, a series of audio-visual scenarios were created to investigate the effects of drone noise on the reported loudness, annoyance and pleasantness of seven different types of urban soundscapes. In soundscapes highly impacted by road traffic noise, the presence of drone noise lead to small changes in the perceived loudness, annoyance and pleasantness. In soundscapes with reduced road traffic noise, the participants reported a significantly higher perceived loudness and annoyance and a lower pleasantness with the presence of the same drone noise. For instance, the reported annoyance increased from 2.3 ± 0.8 (without drone noise) to 6.8 ± 0.3 (with drone noise), in an 11-point scale (0-not at all, 10-extremely). Based on these results, the concentration of drone operations along flight paths through busy roads might aid in the mitigation of the overall community noise impact caused by drones. 相似文献
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Research on connected vehicle environment has been growing rapidly to investigate the effects of real-time exchange of kinetic information between vehicles and road condition information from the infrastructure through radio communication technologies. A fully connected vehicle environment can substantially reduce the latency in response caused by human perception-reaction time with the prospect of improving both safety and comfort. This study presents a dynamical model of route choice under a connected vehicle environment. We analyze the stability of headways by perturbing various factors in the microscopic traffic flow model and traffic flow dynamics in the car-following model and dynamical model of route choice. The advantage of this approach is that it complements the macroscopic traffic assignment model of route choice with microscopic elements that represent the important features of connected vehicles. The gaps between cars can be decreased and stabilized even in the presence of perturbations caused by incidents. The reduction in gaps will be helpful to optimize the traffic flow dynamics more easily with safe and stable conditions. The results show that the dynamics under the connected vehicle environment have equilibria. The approach presented in this study will be helpful to identify the important properties of a connected vehicle environment and to evaluate its benefits. 相似文献
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Vehicle speed trajectory significantly impacts fuel consumption and greenhouse gas emissions, especially for trips on signalized arterials. Although a large amount of research has been conducted aiming at providing optimal speed advisory to drivers, impacts from queues at intersections are not considered. Ignoring the constraints induced by queues could result in suboptimal or infeasible solutions. In this study, a multi-stage optimal control formulation is proposed to obtain the optimal vehicle trajectory on signalized arterials, where both vehicle queue and traffic light status are considered. To facilitate the real-time update of the optimal speed trajectory, a constrained optimization model is proposed as an approximation approach, which can be solved much quicker. Numerical examples demonstrate the effectiveness of the proposed optimal control model and the solution efficiency of the proposed approach. 相似文献
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《Transportation Research Part A: General》1984,18(5-6):421-429
Current traffic control systems which customarily give no direct information to the driver could benefit by the addition of dynamic advisory speed signs. Such signs, first introduced in the 1950s, can enable drivers to pass through successive green signals and give reduced fuel consumption, stops, travel time, emissions, noise and accidents. To attempt to quantify these reductions, a discrete vehicle simulation using program MULTSIM has been run on a 6 km idealized road and also on 2.3 km of the multi-lane arterial, Military Road, Sydney. Typically, with all drivers complying, fuel savings of the order of 10% and a halving of stops have been predicted. Travel time reductions and fuel savings depend on the coordination speed. Higher coordination speeds favour travel time savings over fuel consumption reductions, whilst lower coordination speeds favour fuel savings. Operation near the minimum fuel consumption speed is desirable. Traffic management could benefit from the change in shape of platoons. This should allow more stringent signal timing in adaptively controlled networks, giving greater flexibility for operational designs. 相似文献
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An analysis on long term emission benefits of a government vehicle fleet replacement plan in northern illinois 总被引:1,自引:1,他引:0
There have been a number of studies of the effectiveness of vehicle scrappage programs, which offer incentives to accelerated
scrappage of older vehicles often thought to be high emitters. These programs are voluntary and aimed at replacement of household
vehicles. In contrast, there is a gap in knowledge related to the emissions benefits of government fleet replacement (retirement)
programs. In this study, the efficacy of a fleet replacement program for a local government agency in Northern Illinois, the
Forest Preserve of DuPage County (FPDC), is examined using a probabilistic vehicle survival model that accounts for time-varying
covariates such as vehicle age and gasoline price. The vehicle lifetime operating emissions are calculated based on the estimated
vehicle survival probabilities from the survival model and compared with those derived using the EPA default fleet used in
MOBILE6 and the fleet represented by the Oak Ridge National Laboratory (ORNL) survival curve. The results suggest that while
there may be short term emission benefits of the FPDC fleet replacement plan, the long-term emission benefits are highly sensitive
to economic factors (e.g., future gasoline price) and exhibit a decreasing trend. This indicates that an adaptive multi-stage
replacement strategy as opposed to a fixed one is preferable to achieve optimal cost effectiveness.
Dr. Jie Lin (Jane) is an assistant professor in Department of Civil and Materials Engineering and a researcher with the Institute for Environmental Science and Policy at University of Illinois at Chicago. Her current research is focused on transportation sustainability through holistic modeling of energy consumption and emissions associated with private, freight, and public transportation activities. Dr. Cynthia Chen is an assistant professor in the civil engineering department at City College of New York. Her research expertise and interests cover travel behavior analysis, land use and transportation, transportation safety, and environmental analysis. Dr. Deb Niemeier is a professor at UC Davis and her current research focus is on the nexus between transportation, land use and climate change, particularly how land use and transportation decisions affect energy consumption and contribute to climate change. She is considered an expert on transportation-air quality modeling and policy and sustainability. 相似文献
Debbie A. NiemeierEmail: |
Dr. Jie Lin (Jane) is an assistant professor in Department of Civil and Materials Engineering and a researcher with the Institute for Environmental Science and Policy at University of Illinois at Chicago. Her current research is focused on transportation sustainability through holistic modeling of energy consumption and emissions associated with private, freight, and public transportation activities. Dr. Cynthia Chen is an assistant professor in the civil engineering department at City College of New York. Her research expertise and interests cover travel behavior analysis, land use and transportation, transportation safety, and environmental analysis. Dr. Deb Niemeier is a professor at UC Davis and her current research focus is on the nexus between transportation, land use and climate change, particularly how land use and transportation decisions affect energy consumption and contribute to climate change. She is considered an expert on transportation-air quality modeling and policy and sustainability. 相似文献
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时速200 km动车组通过隧道时空气动力学效应现场试验与研究 总被引:2,自引:1,他引:1
与常规铁路隧道不同,客运专线铁路隧道设计除了要考虑满足围岩稳定性、建筑限界等外,还必须考虑高速列车在隧道中运行时所诱发的空气动力学效应的影响。文章通过遂渝线200km/h提速综合试验中的隧道气动力及结构动力学试验,对200 km/h动车组通过隧道内和列车上瞬变压力、空气动力荷载、列车风、微气压波等进行分析与研究,从而为时速200 km/h客运专线隧道的设计提供依据。 相似文献
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This study provide a straightforward way of examining the rebound effects of switching to more fuel efficient technologies, as well as determining the distribution of the effects in the household sector, including both the residential and transport sectors. A SP-off-RP survey conducted in Japan in 2012 asked people to state their preference for the reallocation behaviors after informing them of their annual operating cost saving resulting from the vehicle efficiency improvement. Coupled who save money from relocation are more likely to spend this either on housing features or transport; supporting the idea of rebound effects, although not only limited to within the transport sector. Regarding the distribution of rebound effects, domestic appliances are more likely to be affected than vehicles. 相似文献
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Discrete choice modeling is experiencing a reemergence of research interest in the inclusion of latent variables as explanatory variables of consumer behavior. There are several reasons that motivate the integration of latent attributes, including better-informed modeling of random consumer heterogeneity and treatment of endogeneity. However, current work still is at an early stage and multiple simplifying assumptions are usually imposed. For instance, most previous applications assume all of the following: independence of taste shocks and of latent attributes, exclusion restrictions, linearity of the effect of the latent attributes on the utility function, continuous manifest variables, and an a priori bound for the number of latent constructs. We derive and apply a structural choice model with a multinomial probit kernel and discrete effect indicators to analyze continuous latent segments of travel behavior, including inference on the energy paradox. Our estimator allows for interaction and simultaneity among the latent attributes, residual correlation, nonlinear effects on the utility function, flexible substitution patterns, and temporal correlation within responses of the same individual. Statistical properties of the Bayes estimator that we propose are exact and are not affected by the number of latent attributes. 相似文献
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The 1990 Clean Air Act Amendments (CAAA) and the Intermodal Surface Transportation Efficiency Act of 1991 (ISTEA) have defined a set of transportation control measures to counter the increase in the vehicle emissions and energy consumption due to increased travel. The value of these TCM strategies is unknown as there is limited data available to measure the travel effects of individual TCM strategies and the models are inadequate in forecasting changes in travel behavior resulting from these strategies. The work described in this paper begins to provide an operational methodology to overcome these difficulties so that the impacts of the policy mandates of both CAAA and ISTEA can be assessed. Although the framework, as currently developed, falls well short of actually forecasting changes in traveler behavior relative to policy options designed to encourage emissions reduction, the approach can be useful in estimating upper bounds of certain policy alternatives in reducing vehicle emissions. Subject to this important limitation, the potential of transportation policy options to alleviate vehicle emissions is examined in a comprehensive activity-based approach. Conclusions are drawn relative to the potential emissions savings that can be expected from efficient trip chaining behavior, ridesharing among household members, as well as from technological advances in vehicle emissions control devices represented by replacing all of the vehicles in the fleet by vehicles conforming to present-day emissions technology. 相似文献
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Many emission models have been developed for estimating the impact of transport policies on vehicle emissions. Macroscopic models, such as MOBILE and COPERT, are used for area analysis, while microscopic models, such as CMEM, are applied for corridor analysis. It is well known that driving dynamics are critical for estimating vehicle emissions. MOVES can be used for both macroscopic and microscopic emission analysis, and its advantage lies in the consideration of driving dynamics. Using a bottom-up approach, we study the impact of license plate restriction policy on vehicle emission reduction by localizing the emission rates in MOVES according to the vehicle emission standards in China. We implement the approach to evaluate the impact on the total vehicle emissions in Hangzhou, China before and after the implementation of license plate restriction policy. In the restricted region, the reductions of total Vehicle Kilometer Traveled (VKT) and total emissions are 9.6% and 6.9%, respectively. The result shows that the license plate restriction policy is effective in achieving the targeted emission reduction. 相似文献
15.
To accurately estimate real-world vehicle emission at 1 Hz the road grade for each second of data must be quantified. Failure to incorporate road grade can result in over or underestimation of a vehicle’s power output and hence cause inaccuracy in the instantaneous emission estimate. This study proposes a simple LiDAR (Light Detection And Ranging) – GIS (Geographic Information System) road grade estimation methodology, using GIS software to interpolate the elevation for each second of data from a Digital Terrain Map (DTM). On-road carbon dioxide (CO2) emissions from a passenger car were recorded by Portable Emission Measurement System (PEMS) over 48 test laps through an urban-traffic network. The test lap was divided into 8 sections for micro-scale analysis. The PHEM instantaneous emission model (Hausberger, 2003) was employed to estimate the total CO2 emission through each lap and section. The addition of the LiDAR-GIS road grade to the PHEM modelling improved the accuracy of the CO2 emission predictions. The average PHEM estimate (with road grade) of the PEMS measured section total CO2 emission (n = 288) was 93%, with 90% of the PHEM estimates between 80% and 110% of the PEMS recorded value. The research suggests that instantaneous emission modelling with LiDAR-GIS calculated road grade is a viable method for generating accurate real-world micro-scale CO2 emission estimates. The sensitivity of the CO2 emission predictions to road grade was also tested by lessening and exaggerating the gradient profiles, and demonstrates that assuming a flat profile could cause considerable error in real-world CO2 emission estimation. 相似文献
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Nature of influence of out‐of‐vehicle time‐related attributes on transit attractiveness: a random parameters logit model analysis 下载免费PDF全文
This paper describes the nature of the impacts of walking distances and waiting time on transit use. The relative trade‐offs of walking and transfer components with other transit service attributes are also discussed. A total of 449 completed stated‐preference interviews were collected; with six observations from each respondent, the total number of observations was 2694. This data set was used to estimate the coefficients in different utility functions using a random parameters logit model. The results demonstrated that walking distances to and from transit stops have important and significant nonlinear negative influences on the attractiveness of transit. Transfer waiting time was also shown to have a significant nonlinear negative impact on transit attractiveness. The random parameters logit model had a better model fit than the standard logit model. Some of the findings obtained here are novel, while others are consistent with previous works. These findings have implications for both theory and practice. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献