What cognitive mechanisms predict travel mode choice? A systematic review with meta-analysis

Reduced private car use can limit greenhouse gas emissions and improve public health. It is unclear, however, how promotion of alternative transport choices can be optimised. A systematic review and meta-analysis was conducted to identify potentially modifiable cognitive mechanisms that have been related to car use and use of alternative transport modes. A qualitative synthesis of measures of potentially modifiable mechanisms based on 43 studies yielded 26 conceptually distinct mechanism categories. Meta-analyses of associations between these mechanisms and car use/non-use generated 205 effects sizes (Pearson’s r) from 35 studies. The strongest correlates of car use were intentions, perceived behavioural control, attitudes and habit. The strongest correlates of alternative transportation choices were intentions, perceived behavioural control and attitudes. Implications for researchers and policy implementation are discussed.     

青藏铁路格拉段扩能改造方案比选

青藏线格拉段是西藏自治区对外铁路货物运输的主通道,目前,青藏线格拉段扩能改造工程已经完工,线路输送能力可适应至2025年.随着西藏自治区同内地之间的物资交流和人员往来迅猛增长,格拉段运输能力难以满足未来西藏自治区的发展需求,需提高其线路运输能力.结合既有铁路的运营现状及近、远期预测客货运量,对青藏铁路格拉段扩能改造方案...     

哈大客运专线信号系统工程设计探讨

本文简要介绍了哈尔滨至大连铁路客运专线信号系统设计方案,并对一些关键技术问题进行了探讨。     

基于文件内外访问倾向性的流调度策略

提出了一种网上教学平台上基于文件内外访问倾向性的视频流调度策略.描述了系统架构、存储策略、调度策略与算法.通过对现有流调度算法的研究,结合视频文件内外访问倾向性,提出了一种新的流调度算法.理论分析和仿真实验表明:该算法可有效提高系统吞吐量和热门影片的命中率,降低系统平均等待时间.     

Assessing the energy and greenhouse gas emissions mitigation effectiveness of potential US modal freight policies

This paper estimates the total embodied energy and emissions modal freight requirements across the supply chain for each of over 400 sectors using Bureau of Transportation Statistics Commodity Flow Survey data and Bureau of Economic Analysis economic input-output tables for 2002. Across all sectors, direct domestic truck and rail transportation are similar in magnitude for embodied freight transportation of goods and services in terms of ton-km. However, the sectors differ significantly in energy consumption, greenhouse gas emissions, and costs per ton-km. Recent pressure to reduce energy consumption and emissions has motivated a search for more efficient freight mode choices. One solution would be to shift freight transportation away from modes that require more energy and emit more (e.g., truck) to modes that consume and emit less (e.g., rail and water).Our results show there are no individual sectors for which targeting changes would significantly decrease the total freight transportation energy and emissions, therefore we have also looked at the prospect of policies encouraging many sectors to shift modes. There are four scenarios analyzed: (1) shifting all truck to rail, shifting top 20% sector mode choice, (2) based on their emissions, (3) based on a multi-attribute analysis, and (4) increasing truck efficiency (e.g., mpg). Increasing truck efficiency by 10% results in similar energy and emissions reductions (approximately 7% for energy and 6% for emissions) as targeting the top 20% of sectors when selected based on emissions, whereas selecting the top 20% based on availability to shift from truck results in slightly less reductions of energy and emissions. Implementing policies to encourage higher efficiency in freight trucks may be a sufficient short term goal while efforts to reduce truck freight transportation through sectoral policies are implemented in the long term.     

A structural analysis of vehicle design responses to Corporate Average Fuel Economy policy

The US Corporate Average Fuel Economy (CAFE) regulations are intended to influence automaker vehicle design and pricing choices. CAFE policy has been in effect for the past three decades, and new legislation has raised standards significantly. We present a structural analysis of automaker responses to generic CAFE policies. We depart from prior CAFE analyses by focusing on vehicle design responses in long-run oligopolistic equilibrium, and we view vehicles as differentiated products, taking demand as a general function of price and product attributes. We find that under general cost, demand, and performance functions, single-product profit maximizing firm responses to CAFE standards follow a distinct pattern: firms ignore CAFE when the standard is low, treat CAFE as a vehicle design constraint for moderate standards, and violate CAFE when the standard is high. Further, the point and extent of first violation depends upon the penalty for violation, and the corresponding vehicle design is independent of further standard increases. Thus, increasing CAFE standards will eventually have no further impact on vehicle design if the penalty for violation is also not increased. We implement a case study by incorporating vehicle physics simulation, vehicle manufacturing and technology cost models, and a mixed logit demand model to examine equilibrium powertrain design and price decisions for a fixed vehicle body. Results indicate that equilibrium vehicle design is not bound by current CAFE standards, and vehicle design decisions are directly determined by market competition and consumer preferences. We find that with increased fuel economy standards, a higher violation penalty than the current stagnant penalty is needed to cause firms to increase their design fuel economy at equilibrium. However, the maximum attainable improvement can be modest even if the penalty is doubled. We also find that firms’ design responses are more sensitive to variation in fuel prices than to CAFE standards, within the examined ranges.     

Impacts of Kra Canal and its toll structures on tanker traffic

This article discusses the proposed Kra Canal and its impacts on the tanker market from an economic perspective. We forecast tanker size distributions and further analyze the impacts of toll structures on tanker traffic. The forecast for tanker size distributions is based on distance savings for tankers as potential users of the Kra Canal. The database covers 105 busiest oil transport routes through the Strait of Malacca for the three-year period 2013–2015. Forecasts for individual routes are achieved using an autoregressive model. Two toll polices, namely the willingness-to-pay policy and the differential-pricing policy, are analyzed in order to maximize the annual toll income of the Kra Canal. The findings for the proposed Kra Canal will attract large vessels from the Strait of Malacca. An interesting finding is that the Kra Canal becomes more profitable during an unfavorable tanker market situation when the time-charter rate is low and fuel price is high. The article concludes with a policy that satisfies the goals of canal operator and government.     

Port competition in Latin America and the Caribbean: the role of concessions and competition policy

Appropriate port regulation and competitive forces tend to be related to higher levels of operational and economic performance of ports. From a policy-making perspective, pursuing efficiency and securing competition in ports to reach a level playing field is a two-step process requiring (1) ex-ante regulations to set the rules that maximize the competition for the market, especially when the policy objective is to attract private operations to ports on competitive concession processes and (2) ex-post competition policy to monitor and preserve competition in the market. This paper studies port regulation in Latin America and the Caribbean (LAC) from a competition perspective, analyzing both ex-ante and ex-post policies implemented in the region. The analysis reveals that the competitive environment in LAC is low, giving room for possible anticompetitive practices in the LAC port sector. Since the end of the 1990s, approximately 80% of container terminals in the region were granted to only five companies. Chile and Mexico have been found to be the best practices in the region, with better conditions assuring robust competition in the market. The main policy implication from this analysis is the need for a stronger involvement of antitrust agencies throughout the port concession processes.     

Governance of Shipping Emission of SOx in China's Coastal Waters: The SECA Policy,Challenges, and Directions

Emission governance of air pollutants from ships is a common challenge for the world's shipping industry. Under the framework of the International Maritime Organization (IMO), Europe, North America, and other developed regions and countries have established strict ship Emission Control Areas (ECAs). With some of the largest ports in the world, China suffers severe air pollution from ships, posing a threat to the air quality and public health of the coastal cities. To strengthen the control and supervision over air pollutants, such as ship-emitted sulfur oxides (SO_x) in coastal areas, China issued a Sulfur Emission Control Area (SECA) policy for ships in January 2016. However, the new SECA policy lags far behind IMO's existing ECA policies, and continues to face many challenges during implementation. This paper outlines the main framework of China's ship SECA policy, analyzes the legal governance basis, discusses major potential challenges for implementing the policy, and puts forward suggestions for future governance. This research aims to promote the effectiveness of China's sulfur emission-reducing SECA policy by putting forth novel ideas for policymakers and stakeholders.     

Evolution of green shipping research: themes and methods

Over the past 30 years, there have been growing concerns on the environmental impacts of maritime transportation, which have attracted great attention from both academia and practitioners. Understanding developments in this area can help guide future research. We conducted a comprehensive review of green shipping research, comprising 213 papers published in transportation journals in SSCI of 2017 over the period 1988–2017. We find that research on green shipping has increased greatly since 2012, accounting for 77.5% of the reviewed papers. The main focus today on green shipping was on air pollution, and the classification of green shipping practice, such as technical measures, operational options, market-based measures, and recycling and reusing, is becoming clear. According to the existing studies, future research on green shipping must strengthen technology research to not only solve practical problems, but also to establish a theoretical green shipping system. Moreover, researchers from different countries could cooperate with each other to give effective suggestions on setting standards and laws of green shipping. Finally, we identify the future research themes will focus on setting up green shipping system and legislation and policy.