首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
Abstract

This article proposes new models for estimating transport demand using a genetic algorithm (GA) approach. Based on population, gross national product and number of vehicles, four forms of the genetic algorithm transport planning (GATP) model are developed – one exponential and the others taking quadratic forms – and applied to Turkey. The best fit models in terms of minimum total average relative errors in the test period are selected for future estimation. Demand management strategies are proposed based on three scenarios: restricting private car use, restricting truck use and the simultaneous management of private car use and goods movement. Results show that the GATP model may be used to estimate transport demand in terms of passenger-kilometers traveled (pass-km), vehicle-kilometers traveled (veh-km) and ton-kilometers completed (ton-km). Results also show that the third scenario – simultaneous restrictions on private car use and goods movement – could reduce total veh-km by about 35% by 2025 in this study of Turkish rural roads.  相似文献   

2.

Transport accounts for about 25% of global CO 2 emissions. Transport activities are on the rise in the coming decades. Would associated CO 2 emissions move upwards as well, and at what rate? The present paper explores the future of these CO 2 emissions, starting from four scenarios for global transport. Considering fuel consumption, energy efficiencies in transport, occupancy rates of transport means, size of cars on the market, and possible environmental policies we find CO 2 emissions are persistently increasing, especially in the less wealthy areas of the world. In Europe, policies that attempt to control mobility and also limit CO 2 emissions may succeed in reducing emissions growth by about 30%. Efforts to increase energy efficiency of transport, in particular road transport, would contribute most to such reduction.  相似文献   

3.

This article presents a simulation of four quantitative scenarios using the applied general equilibrium model WorldScan . The scenarios are constructed to study the effects of globalization on transport and the environment. They contain different assumptions on the degree of globalization, technical progress, migration and energy policies. WorldScan focuses on long-term economic growth, trade and specialization patterns. It quantifies the economic content of the scenarios and the volume growth of energy and emissions between 1995 and 2050. The scenario outcomes show that emission growth quadruples with high economic growth without any energy-efficient technologies and environmental legislation. However, in an ecological scenario which combines energy-efficient technologies, environmental legislation and modest economic growth, global emissions hardly increase.  相似文献   

4.
Abstract

This paper examines 42 business‐as‐usual (BAU) scenarios for future transport and traffic development in the Netherlands from the period 1970 to 2000. An important aspect of these scenarios is that they indicate the potential future state of the transport system if the policies in place at the time continue unchanged, thus raising issues which may require a policy response. This paper shows that in most of the important BAU transport scenario results of the past in the Netherlands, such as future car use and transport emissions, the policy makers were not misled. The prognoses for traffic congestion are an important exception as they underestimated the congestion problems that would arise. This paper shows that, based on the research it examines, BAU transport forecasting is an inaccurate practice. It is recommended that the BAU scenario designer communicates this high inaccuracy, enabling the policy maker to include the inherent future uncertainty in their decision‐making.  相似文献   

5.

This paper presents an overview of some recent developments in and policy issues relating to integrated transport systems in the European Union (EU). Both goods and passenger transport systems are considered in the context of actions recently undertaken and supported by the EU. The paper considers the very general background of these systems at the EU scale and offers insights into some recent successful and promising policy, real-life, and research attainments. In addition, it attempts to identify some directions for future actions in fields such as transport policy, transport technology, transport economics and transport scenarios.  相似文献   

6.
Abstract

This paper presents a decision support methodology for long-range planning of transport systems that exhibits strategic flexibility and stochastic system parameters. Unlike one-off strategic decisions, flexible decisions should be dynamically reformulated with time. The proposed methodology is based on the construction of a tree structure of multiple interlinked tactical planning problems, each associated with a scenario in the tree, where problems under scenarios at intermediate dates incorporate in their formulation the solution of the corresponding problems associated with past (future) connected scenarios. The resulting tree structure of interconnected planning decisions becomes a strategic-tactical decision support system that allows managers to formulate suitable flexible strategic decisions that mitigate the consequences associated with downside scenarios while taking advantage of the upside opportunities. The methodology is applied to the planning of a fleet deployment through charter contracts where contract prices depend on both market behavior and the duration of the contract itself.  相似文献   

7.

To contribute to a sustainable society, considerable reduction in energy use and CO2 emissions should be achieved. This paper presents the results of calculations exploring the energy use reduction potential of passenger transport for Western Europe (OECD Europe minus Turkey). For these calculations, three types of options are defined emphasizing technological, infrastructural and behavioural change. By 2050, technological improvements may reduce energy use per passenger-km by - 30%. Adding infrastructural options, an energy reduction of > 50% by 2050 can be realised. To achieve further energy reductions, options with a large behavioural impact should also be implemented. This results in an 80% energy reduction potential in the transport sector by 2050. To calculate the reduction potential on OECD Europe level, one should factor in expectations concerning mobility growth. Two mobility development scenarios are used. Both scenarios foresee a net decrease in total energy use of 20% with the introduction of the technological and infrastructural improvement options. Adding options emphasizing behavioural change results in a net reduction potential of - 60% by 2050.  相似文献   

8.
Abstract

Part 1 elicited major research issues and opportunities in the transport sector in the EEC from an examination of a range of planning scenarios. This article relates those issues and opportunities to the needs of the EEC transport sector policy formation and derives a set of research recommendations. The respective roles of the EEC and other institutions in developing and meeting the research needs are then discussed, concluding with some institutional proposals for the strengthening of the organization of the strategic research effort of the EEC in the transport sector.  相似文献   

9.
For the UK to meet their national target of net zero emissions as part of the central Paris Agreement target, further emphasis needs to be placed on decarbonizing public transport and moving away from personal transport (conventionally fuelled vehicles (CFVs) and electric vehicles (EVs)). Electric buses (EBs) and hydrogen buses (HBs) have the potential to fulfil requirements if powered from low carbon renewable energy sources.A comparison of carbon dioxide (CO2) emissions produced from conventionally fuelled buses (CFB), EBs and HBs between 2017 and 2050 under four National Grid electricity scenarios was conducted. In addition, emissions per person at different vehicle capacity levels (100%, 75%, 50% and 25%) were projected for CFBs, HBs, EBs and personal transport assuming a maximum of 80 passengers per bus and four per personal vehicle.Results indicated that CFVs produced 30 gCO2 km−1 per person compared to 16.3 gCO2 km−1 per person by CFBs by 2050. At 100% capacity, under the two-degree scenario, CFB emissions were 36 times higher than EBs, 9 times higher than HBs and 12 times higher than EVs in 2050. Cumulative emissions under all electricity scenarios remained lower for EBs and HBs.Policy makers need to focus on encouraging a modal shift from personal transport towards sustainable public transport, primarily EBs as the lowest level emitting vehicle type. Simple electrification of personal vehicles will not meet the required targets. Simultaneously, CFBs need to be replaced with EBs and HBs if the UK is going to meet emission targets.  相似文献   

10.
Milan Janic 《运输评论》2013,33(1):81-104
Abstract

This paper presents a review of the research on the sustainability of transport systems carried out over the last 15 years for the European Union (EU), identifies some missing gaps and elaborates on the prospective future ideas. The general concept of sustainable development and definitions of sustainability of transport systems and their operationalization are discussed. These are followed by the general review of the research on the sustainable transport systems funded by the EU 4th, 5th and 6th Framework Programs. Consequently, refinement of existing and/or developing an innovative system for monitoring sustainability of transport systems in the EU based on the indicator system(s) of performances is suggested as a prospective research idea.  相似文献   

11.
ABSTRACT

Efficient planning for demand responsive transit (DRT) can contribute to fulfilling the first/last mile transport needs for users of a major transit line. With the advancement in communication technologies, the internet is expected to assist this growing need of providing first/last mile connectivity. This is proposed to be achieved through a network created by Internet of Things (IoT). This paper evaluates the effect of implementation of IoT on service quality (or disutility) of DRT for two scenarios – with enabled-IoT (e-IoT) and with disabled-IoT (d-IoT). Data from five different DRT-like systems known as Call-n-Ride (CnR) routes operating in Denver, Colorado, are used for evaluation purposes. These CnR routes are Meridian, Interlocken, South Inverness, Broomfield and Louisville. Results show that, in general, all CnR routes would experience more than a 58 percent decrease in disutility if their operations were based on ‘with e-IoT’ operations. Interlocken would record the largest percentage decrease (74 percent) in disutility if its route service switched from the ‘with d-IoT’ to the ‘with e-IoT’ scenario.  相似文献   

12.

Environmental charges are one of the economic instruments for controlling externalities. Their application to commercial flights has become a preferred method of encouraging the sustainable development of the air transport industry. Two kinds of externalities, aircraft noise and engine emissions, both generating profound impacts on human beings and on the environment, are considered here. The hedonic price method is applied to calculate the social cost of aircraft noise during the landing and take-off stages of the flight. The marginal impact of each flight with specific aircraft/engine combinations is derived for the allocation of aggregate noise social costs. In contrast, the dose - response method is applied to estimate the social cost of each engine exhaust pollutant during different flight modes. The combination of aircraft noise and engine emissions social costs is then evaluated on the basis of several environmental charge mechanism scenarios, using Amsterdam Airport Schiphol as a case study. It is shown that the current noise or engine emissions related charges at airports are lower than the actual social costs of their respective externalities. The implications of charge mechanism scenarios are subsequently discussed and evaluated in terms of their impacts on airline costs, airfares and passenger demand.  相似文献   

13.

A trio of closely related land‐use/transport interaction models was developed using Marcial Echenique & Partners’ software package MEPLAN. The models were for the cities of Bilbao, (Spain), Dortmund (West Germany) and Leeds (England). All were calibrated using data drawn from earlier studies. The three models were used to predict the effects (relative to a base case) of a common programme of land‐use and transport policies or scenarios. This paper explains briefly the theoretical basis of the MEPLAN package as applied to urban models such as these three; describes the types of policies that have been assessed; and presents some of the key results.  相似文献   

14.
Book review     
Werner Brög 《运输评论》2013,33(1):99-101
Abstract

In April 1983, the “Fourth World Conference on Transport Research” was held in Hamburg. For a period of four days, experts from all parts of the world discussed transport research and planning problems. The discussions were divided into eight so‐called ‘sub‐topics’. Fortunately, one of the sub‐topics, ‘Man and his Transport Behaviour’ (chaired by Moshe Ben‐Akiva, U.S.A. and Werner Brog, Federal Republic of Germany) dealt with the individual and his behaviour. This complemented the traditionally supply‐oriented thinking of the transport planners by introducing the demand component which had frequently been neglected in the past. Since the view has become increasingly widespread that transport is meant to serve people and thus that research should emphasize the (potential) users of the transport system, the number of papers submitted and presented on this sub‐topic was especially large.

However, the number of papers which could be included in the ‘Conference Proceedings’ was limited and this would have meant that a number of interesting documents could not be published. Therefore, papers on four special areas within this sub‐topic are to be published in four consecutive issues of Transport Reviews. The areas which will be dealt with are ‘Telecommunications’, ‘Non‐Motorised Transport’, ‘Special Problems in Third World Countries’ and ‘Fare Structures in Public Transport’. The papers were selected strictly according to their contents. A brief commentary in each issue explains in turn the reasons for choosing each of the four subject areas.  相似文献   

15.
ABSTRACT

The role of transport in providing access to employment has received considerable attention. Since transport policies may be motivated by assumed effects on employment probability outcomes, it is important to establish the nature of the relationship between transport and employment outcomes. While the majority of the empirical evidence suggests a positive association, it is not conclusive or consistent and often shows mixed results. To address this confusion, our study has systematically reviewed this evidence base and synthesised it through meta-analysis. We first identified 93 studies that quantitatively assessed the impact of transport on employment outcomes. By systematically merging the empirical evidence, this study establishes a positive association between transport and employment outcomes, with varying effects for four identified categories of transport measures (or combinations thereof): car ownership, public transport access, commute times, and job accessibility levels. This positive association persists in studies that control for endogeneity between transport and employment, but a larger evidence base is needed to establish a more robust relationship, in particular for cities and smaller (rural) areas outside the US-context and with regard to public transport. We then selected 20 methodologically comparable studies for inclusion in the meta-analysis. Our meta-regression models clearly demonstrate that car ownership significantly increases individual employment probabilities, in particular among welfare recipients. Young drivers benefit from access to household cars when these are not in use by their parents, and they are more sensitive to the time and cost implications of longer commutes. While our systematic review suggests that better access to public transport and higher levels of job accessibility increases employment probabilities, meta-regression analysis requires more consistent transport measures. The findings in this study are important for policymakers in that they imply that job seekers may benefit from public policies targeted at improving their access to public transport, in particular for people without access to cars and in areas with fewer job opportunities.  相似文献   

16.
Werner Brög 《运输评论》2013,33(4):359-365
Abstract

In April 1983, the “Fourth World Conference on Transport Research” was held in Hamburg. For a period of four days, experts from all parts of the world discussed transport research and planning problems. The discussions were divided into eight so‐called ‘sub‐topics’. Fortunately, one of the sub‐topics, ‘Man and his Transport Behaviour’ (chaired by Moshe Ben‐Akiva, U.S.A. and Werner Brög, Federal Republic of Germany) dealt with the individual and his behaviour. This complemented the traditionally supply‐oriented thinking of the transport planners by introducing the demand component which had frequently been neglected in the past. Since the view has become increasingly widespread that transport is meant to serve people, and thus, that research should emphasize the (potential) users of the transport system, the number of papers submitted and presented on this sub‐topic was especially large.

However, the number of papers which could be included in the ‘Conference Proceedings’ was limited and this would have meant that a number of interesting documents could not be published. Therefore, papers on four special areas within this sub‐topic are to be published in four consecutive issues of Transport Reviews. The areas which will be dealt with are ‘Telecommunications’, ‘Non‐Motorised Transport’, ‘Special Problems in Third World Countries’ and ‘Fare Structures in Public Transport’. The papers were selected strictly according to their contents. A brief commentary in each issue explains in turn the reasons for choosing each of the four subject areas.

Parts 1–3 appeared in Transport Reviews, 4, 99–113, 173–212, 273–298.  相似文献   

17.
Abstract

The expanding older population is increasingly diverse with regard to, for example, age, income, location, and health. Within transport research, this diversity has recently been addressed in studies that segment the older population into homogeneous groups based on combinations of various demographic, health-related, or transport-related factors. This paper reviews these studies and compares the segments of older people that different studies have identified. First, as a result of a systematic comparison, we identified four generic segments: (1) an active car-oriented segment; (2) a car-dependent segment, restricted in mobility; (3) a mobile multi-modal segment; (4) and a segment depending on public transport and other services. Second, we examined the single factors used in the reviewed segmentation studies, with focus on whether there is evidence in the literature for the factors’ effect on older people's travel behaviour. Based on this, we proposed a theoretical model on how the different determinants work together to form the four mobility patterns related to the identified segments. Finally, based on current trends and expectations, we assessed which segments are likely to increase or decrease in future generations of older people and what should be done to support the multi-optional and independent mobility of older people.  相似文献   

18.
Abstract

This paper presents a definition of sustainable urban freight transport (SUFT), based on the existing theories and concepts, and develops an indicator set that describes SUFT. The definition of SUFT makes a categorisation of actions possible which enables actors to select effective strategies towards SUFT. The indicator set consists of two levels: impact indicators – which describe how the urban freight transport violates the principles of sustainability; and performance indicators – which describe different categories determining the characteristics and performance of the urban transport system. A literature study analyses the characteristics determining the performance of actors in the urban freight transport chain. Knowing the current state and improvement potential of the urban freight transport system are prerequisites for defining successful strategies and implementing effective actions.  相似文献   

19.

Freight transfer operations are critical in combined transport networks. In this paper a simulation model and modelling approach to the transfer of cargo between trains at rail terminals is presented. The model is used to study the Port-Bou terminal, the main intermodal terminal at the Spanish-French frontier. Four different gantry crane operation modes to interchange containers between trains are evaluated. These operation rules are tested in several scenarios to examine the critical factors of the system and the best operation rule for each situation. Latest generation software is used to develop the model that incorporates modular programming and enhanced graphic systems for output representation. It allows a dynamic display of the simulated system and, likewise, the possibility of developing modules that can be reused in other studies. The research shows how simulation can be a useful planning tool in the rail transportation context.  相似文献   

20.

The paper summarizes the research results and implications from the DGVII-funded Fourth Framework research project Deployment of Interurban ATT Test Scenarios (DIATS). The objective of DIATS was to identify options available in the short and medium terms, for implementing advanced transport telematics (ATT) systems for motorway-type roads and to develop scenarios of 'highest potential impact' for each of the systems identified. Included are the results of a Delphi study into the most likely deployment scenarios for ATT technologies. The methodology developed to assess the organizational, social, environmental, efficiency, safety and legal concerns associated with new ATT systems is then described. This includes stated preference questionnaires, traffic simulation modelling, driver behaviour assessment using an instrumented vehicle, analysis of accident databases and literature reviews. A multicriteria analysis of the impacts of a range of ATT systems is then presented. In particular, the results discuss the potential impacts of new in-vehicle driver assistance devices such as adaptive cruise control on the operation and effectiveness of existing fixed-infrastructure systems. The paper concludes with a prioritized list of deployment strategies of maximum impact for all of the systems assessed. The research findings are already being applied nationally and a number of field trial assessments that will assist in this are also proposed.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号