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1.
This paper defines the relationship between telecommunications and transportation, by expanding on linkages already identified in the literature, by identifying additional relationships, and by putting these relationships into a robust conceptual framework. There are conceptual, physical, analytical, and regulatory parallels between telecommunications and transportation. Telecommunications affects the demand for, and supply of, transportation — and vice versa. In the broadest sense, all communication requires transportation in order to occur: transportation either of people, of objects, or of electronic impulses. In other words, communication takes place via one or more of those three modes. It is suggested that “communication breeds communication.” That is, the easier it is to communicate (whether through travel or communications), or the more that one or another form of communication takes place, the more that communication as a whole is stimulated. The relative shares of each of the three modes of communication may vary as one mode partially substitutes for another, but the absolute amounts of communication via each mode are likely to increase. Two empirical studies are summarized, one illustrating that teleconferencing increased travel, the other illustrating that telecommuting decreased travel. Other implications for transportation planning are highlighted.  相似文献   

2.
Abstract

This study analyzes aggregate consumer expenditure data from the US between 1984 and 2002, to determine relationships between expenditures on transportation and communications. We first identified 15 categories of goods – nine for transportation, five for communications, and one for all others – and obtained prices for each category across time. Then, we applied the linear approximate almost ideal demand system (AIDS) method for estimating consumer demand functions, aggregating the categories to six (non-personal vehicle (PV), PV capital, PV operation, electronic communications media, print communications media, and all others) due to the small sample size. The results indicate that transportation and communications categories have both substitution and complementarity relationships. The existence of effects in both directions (substitution and complementarity) is testimony to the complexity of the relationships involved, with both generation and replacement possible and happening simultaneously. In addition, expenditures in the transportation categories are generally more income-elastic and price-elastic than those in communications, indicating that communications expenditures are more essential than those for travel. The transportation categories have both substitution and complementarity relationships with each other, while the two communications categories have a substitution relationship.  相似文献   

3.
M. R. Wigan 《Transportation》1987,14(4):395-417
Transport, communications and urban form cover an overlapping area of rising academic and practical concern. This paper traces several of the many themes brought together under different professional banners, and shows how a confluence of interest is emerging.The themes are the developments in urban planning analysis, transport and time use studies, telecommunications and industrial location, all of which contribute to the area of locational effects of improved telecommunications technology, and are affected by alterations in the nature of work and the uses made of time by individuals. The convergence of geographical, planning, transportation and communication developments now requires explicit investigation, as the timings of technological and theoretical developments appear to coincide with the emergence of a significant need to do so. Some of the gaps between present knowledge and expertise that need to be filled are specified.These include the investigation of the testing and use of current land use integrated analyses for road and development assessment, investigation of the nature and characteristics of work and education which are most affected by telecommunications and computer support, development of longitudinal monitoring methods for overall urban development leading indicators, exploitation of newly-available cross-sectional household and city data sets in conjunction with historical data for longitudinal investigations and forward projections, accounting for altered family structure and activity patterns and the anticipation and assessment of probable further technological change, which can and will undermine many current long term commitments.  相似文献   

4.
Using input–output (I–O) accounts provided by the U.S. Department of Commerce, this study investigates the aggregate relationships between the transportation and communications inputs demanded (directly and in total) by all industries in the U.S., and compares the results across time. We analyzed five pairs of Spearman correlations of transportation and communications demands (utilities, manufacturing, and overall) using the direct and total coefficient tables from the ten benchmark input–output years spanning 1947 to 1997. To correctly represent the overall economy-wide relationship, each industry (direct table) or commodity (total table) in the correlation was weighted proportionately to the monetary value of its contribution to the U.S. economy. In the analysis using direct I–O coefficients, we found a pattern of predominant complementarity between transportation and communications manufacturing, and substitution between transportation and communications utilities. There are intriguing indications, however, of a shift from substitution to complementarity in the latter case, beginning around 1987. In the analysis using total I–O coefficients, we found a pattern of complementarity for all years between transportation and communications manufacturing, and a pattern changing from substitution to complementarity for the remaining four pairs (transportation manufacturing and communications utilities; transportation utilities and communications manufacturing; the utilities pair; and the overall pair). Thus, from the industrial perspective (which constitutes a sizable proportion of the total demand for communications and transportation), it is not realistic in modern times to expect telecommunications to substitute for travel. Nevertheless, further research is needed into the specific causes of the observed shift from substitution to complementarity, and current trends should continue to be monitored for any changes.
Patricia L. Mokhtarian (Corresponding author)Email:

Taihyeong Lee   is a Ph.D. candidate in civil and environmental engineering and a graduate student researcher of the Institute of Transportation Studies at the University of California, Davis. His research focuses on the study of travel behavior, and on the impacts of structural changes in industry on relationships between transportation and communications. Patricia L. Mokhtarian   is a professor of civil and environmental engineering, associate director of the Institute of Transportation Studies, and chair of the interdisciplinary Transportation Technology and Policy MS/PhD program at the University of California, Davis. She specializes in the study of travel behavior, and of the impacts of information and communications technology on transportation.  相似文献   

5.
A conceptual analysis of the transportation impacts of B2C e-commerce   总被引:4,自引:1,他引:4  
This paper discusses, at a conceptual level, a number of issues related to the evaluation of the transportation and spatial impacts of e-shopping. We review the comparative advantages of store shopping and e-shopping, and conclude that neither type uniformly dominates the other. We identify the building blocks of the shopping process, and note that information and communications technologies are making possible the spatial and temporal fragmentation and recombination of those elements. We analyze future shopping-related changes in transportation as the net outcome of four different fundamental causes, that can be viewed hierarchically: (1) changes in shopping mode share (i.e. shifts in the proportion of shopping activities conducted through store shopping, e-shopping and other modes), keeping the volume of goods purchased and per capita consumption spending constant; (2) changes in the volume of goods purchased, keeping per capita consumption spending constant; (3) changes in per capita consumption spending, independent of demographic changes; and (4) demographic changes. Some factors result in reduced travel while others lead to increased travel. The combined outcome of all factors does not appear to support any hope that e-shopping will reduce travel on net; to the contrary there may be negative impacts due to increased travel, even if those impacts are likely to be localized and/or small in magnitude for the most part. Thus, on the whole, we are likely (with some exceptions) to see continued adoption of both store shopping and e-shopping. Consumers will blend both forms as they conduct a sequence of shopping activities, and retailers will blend both in marketing to and serving customers. Assessing the transportation impacts of e-shopping – even in the short term, let alone the long term – presents some formidable measurement challenges. Nevertheless, those challenges are worthy of our most creative efforts at solution.  相似文献   

6.
Jongho Rhee 《Transportation》1995,22(4):389-412
Eurasia is the place in which the political and social situations are changing rapidly. In particular, the recent changes in the Soviet Union, China and North Korea will bring about big changes in transportation network in Eurasia. The difficulties of the existing transportation network in this area are examined. Directions for developing transportation networks between Korea, China, Mongolia and Russia are suggested with a focus to the unified Korea. Access to the Middle East, India and Southeast Asia by rail would be possible by connecting the missing links, and its competitiveness could be increased. The establishment of direct air routes can also reduce air passenger-km and fuel consumption quite a lot.  相似文献   

7.
Expo 86, the World Exposition held last year in Vancouver, Canada, was the largest, special-category world's fair ever staged, with 54 international participants. Given the designated theme of transportation and communications, it is interesting to interpret the statements made by the participants in regard to particular sub-theme areas such as urban transit. This paper reviews the presentations (exhibits, demonstrations, conferences, and seminars) developed by all participants in Expo 86 in regard to urban transit technology, and assesses the significance and direction of technological developments in the areas of vehicle and terminal design, network and system operation and control, and planning and management systems.  相似文献   

8.
ABSTRACT

Based on the increasing demands of transportation development, the concept of an Intelligent Transportation System (ITS) has received increasing attention in both academic and industry arenas. It integrates information, communications, computers and other technologies, and applies them in the field of transportation to build an integrated system of people, roads and vehicles by utilizing advanced data communication technologies. It can establish a large, fully functioning, real-time, accurate and efficient transportation management system. Intelligent transportation systems shift the focus from road managers to road users. In order to achieve this purpose, intelligent transportation systems use advanced technology to provide drivers with convenient information to help reduce traffic congestion and to increase available road capacity. This special issue is dedicated to exploring the most recent advances in intelligent transportation systems and big data based on intelligent technology.  相似文献   

9.
Abstract

Effective management of interfaces between procurement, supply, production and distribution for higher efficiency in the supply chain is an important issue in global manufacturing, where the synchronization of production and transportation planning represents important savings in operational costs. This paper focuses on the synchronization of production planning and transportation planning in a production distribution network, where transportation is subcontracted to a professional transportation enterprise (PTE) for vehicle-hiring. Dynamic and flexible numbers of vehicles are used to cater for fast changing market demands. Thus, the number of vehicles to be hired is viewed from the planning point of view as an operational decision considered simultaneously with production and transportation planning. A mathematical model – SPTP/MTDS – for synchronized production and transportation planning under multiple times and direct shipping strategy (MTDS) is discussed, and a Lagrange relaxation decomposition-based two layer decision procedure (LRD-TLDP) is developed. By introducing artificial decision variables and Lagrange multipliers, SPTP/MTDS is decomposed into a production decision sub-problem (SPTP-PD), and a distribution decision sub-problem (SPTP-DD). A priority-based assignment heuristic and a partial chain-based genetic algorithm are developed to solve SPTP-PD and SPTP-DD, respectively. An illustration of the application of the model in an electronic appliance manufacturing enterprise in China is presented.  相似文献   

10.
Freight transport demand is a demand derived from all the activities needed to move goods between locations of production to locations of consumption, including trade, logistics and transportation. A good representation of logistics in freight transport demand models allows us to predict the effects of changes in logistics systems on future transport flows. As such it provides better estimations of the costs of interaction and allows to predict changes in spatial patterns of freight transport flows more accurately. In recent years, the attention for freight modelling has been growing and new research work has appeared aimed at incorporating logistics in freight models. In this paper we review the state of the art in the representation of logistics considerations in freight transport demand models. Our focus is on the service and cost drivers of changes in logistics networks and how these affect freight transport. Our review proceeds along a conceptual framework for modelling that goes beyond the conventional 4-step modelling approach. We identify promising areas for freight modelling that have an integrative function within this framework, such as spatial computable general equilibrium models, supply chain choice models and hypernetwork models.  相似文献   

11.
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   

12.
为降低西部原油管道管输能耗,通过计算管道在不同季节、不同流量下的摩阻损耗,结合管道参数和输油泵特性曲线,分析得出影响输油生产单位能耗的因素包括管输流量和输油温度。进一步计算得出了不同流量和不同季节对应的输油生产单耗。结果表明,流量对输油生产单耗影响较大,西部原油管道管输流量在1 000~1 400 m~3/h区间时生产单耗相对较低;流量大于1 600 m3/h时,生产单耗随流量上升接近线性增长。而输油温度对生产单耗的影响较小,同一流量下冬季生产单耗略高于夏季生产单耗。  相似文献   

13.
Globalization, greenhouse gas emissions and energy concerns, emerging vehicle technologies, and improved statistical modeling capabilities make the present moment an opportune time to revisit aggregate vehicle miles traveled (VMT), energy consumption, and greenhouse gas (GHG) emissions forecasting for passenger transportation. Using panel data for the 48 continental states during the period 1998-2008, the authors develop simultaneous equation models for predicting VMT on different road functional classes and examine how different technological solutions and changes in fuel prices can affect passenger VMT. Moreover, a random coefficient panel data model is developed to estimate the influence of various factors (such as demographics, socioeconomic variables, fuel tax, and capacity) on the total amount of passenger VMT in the United States. To assess the influence of each significant factor on VMT, elasticities are estimated. Further, the authors investigate the effect of different policies governing fuel tax and population density on future energy consumption and GHG emissions. The presented methodology and estimation results can assist transportation planners and policy-makers in determining future energy and transportation infrastructure investment needs.  相似文献   

14.
The logistics industry plays a critical role in boosting China’s economic development, although at significant externality costs. Using the 1980–2010 data, we examine the historical evolution of energy consumption in China’s logistics industry. The logarithmic mean Divisia index (LMDI) method was used to analyze the key factors that drove the chronicle changes in logistics energy consumption in China. Changes in energy consumption of China’s logistics industry are attributed to growth in logistics activity, modal shift in freight transportation, increases in transport intensity, and overall improvements in energy intensity: (1) China’s logistics industry enjoyed fast growth with an average annual growth rate of 9.65% from 1980 to 2010. Increase in logistics activity has been the major force driving up logistics energy consumption (accounting for 48.8% of logistics energy increase); (2) Logistics energy consumption increased by 22.91 times, averaging at 11.9% growth per year. Fuel consumption in highway transportation has become more dominant in logistics energy consumption; (3) While changes in logistics activities, transportation modes and transport intensity pushed up logistics energy consumptions, improvements in energy intensity helped significantly to curb the energy rise in China’s logistics industry.  相似文献   

15.
CO2 emissions are increasing because of the growth in the cross-border supply chain, which is leading the locations of assembly plants and suppliers to spread across a wider area. Given that one passenger vehicle needs more than 20,000 components and parts, the automobile industry exploits the cross-border supply chain. Recently, the free cross-border movement of people, goods, capital, and information has accelerated in Asia. Therefore, a sustainable cross-border supply chain is required to reduce both CO2 emissions and cost. This study estimates total CO2 emissions per vehicle including production and transportation processes in Thailand and neighboring countries and the change in CO2 emissions based on future policy scenarios that consider the automobile market and locational conditions in 2030. The results show that locating production close to the place of consumption and the electricity emissions factors in each country should be considered.  相似文献   

16.
The United States transportation sector consumes 5 billion barrels of petroleum annually to move people and freight around the country by car, truck, train, ship and aircraft, emitting significant greenhouse gases in the process. Making the transportation system more sustainable by reducing these emissions and increasing the efficiency of this multimodal system can be achieved through several vehicle-centric strategies. We focus here on one of these strategies – reducing vehicle mass – and on collecting and developing a set of physics-based expressions to describe the effect of vehicle mass reduction on fuel consumption across transportation modes in the U.S. These expressions allow analysts to estimate fuel savings resulting from vehicle mass reductions (termed fuel reduction value, FRV), across modes, without resorting to specialized software or extensive modeling efforts, and to evaluate greenhouse gas emission and cost implications of these fuel savings. We describe how FRV differs from fuel intensity (FI) and how to properly use both of these metrics, and we provide a method to adjust FI based on mass changes and FRV. Based on this work, we estimate that a 10% vehicle mass reduction (assuming constant payload mass) results in a 2% improvement in fuel consumption for trains and light, medium, and heavy trucks, 4% for buses, and 7% for aircraft. When a 10% vehicle mass reduction is offset by an increase in an equivalent mass of payload, fuel intensity (fuel used per unit mass of payload) increases from 6% to 23%, with the largest increase being for aircraft.  相似文献   

17.
This article reviews empirical studies of how employer-paid parking affects employees' travel choices. A strong effect is found: parking subsidies greatly increase solo driving. When employers reduce or remove parking subsidies, a significant number of solo drivers shift to carpools and/or transit. This conclusion is based on studies of parking subsidies in a variety of circumstances, including central city and suburban areas, private and public employers, and clerical and professional employees. Three measures are developed to compare changes in commute patterns: changes in the share of solo drivers. changes in the number of autos driven to work per 100 employees, and the parking price elasticity of demand for solo driving. The studies reviewed here show that 19 to 81 percent fewer employees drive to work alone when they pay for their own parking. Because 90 percent of American commuters who drive to work receive employer-paid parking, these findings are significant for designing transportation policies to reduce air pollution, traffic congestion, and energy consumption.  相似文献   

18.
Reducing energy consumption and controlling greenhouse gas emissions are key challenges for urban residents. Because urban areas are complex and dynamic, affected by many driving factors in terms of growth, development, and demographics, urban planners and policy makers need a sophisticated understanding of how residential lifestyle, transportation behavior, land-use changes, and land-use policies affect residential energy consumption and associated CO2 emissions. This study presents an approach to modeling and simulating future household energy consumption and CO2 emissions over a 30-year planning period, using an energy-consumption regression approach based on the UrbanSim model. Outputs from UrbanSim for a baseline scenario are compared with those from a no-transportation-demand model and an Atlanta BeltLine scenario. The results indicate that incorporation of a travel demand model can make the simulation more reasonable and that the BeltLine project holds potential for curbing energy consumption and CO2 emissions.  相似文献   

19.

Today, the extended transport infrastructure along with the communications and information technologies are to a large extent the generator of integration processes all over Europe. Novelties in this area have brought about important changes in the production conditions, distribution and consumption, which exert influence on the changing of economic structure, including similar changes in social, cultural and political relations. In the future, the social and economic development of Slovenia will depend on proportionate development of regions and on the embodiment of Slovenia in a wider European space. The transport infrastructure of Slovenia, along with its transport system, should be integrated in the European transport system in such a way that the developmental interest of Slovenia is fully highlighted and included to an optimum extent in the course of Slovenia's integration to the EU.  相似文献   

20.
Starkie  D. N. M. 《Transportation》1974,3(4):323-334
Evidence of the inability of transport models to elucidate policy is cited and reasons for this weakness are then suggested.Attention is drawn to the fundamental changes in both opinion and policy currently taking place. There is less concern with accessibility per se and rather more concern with the provision of adequate or minimum accessibility for certain social groups. More emphasis is placed also on the environmental aspects of transportation.The implications of these changes are outlined. It is not at all clear that the need to adapt and up-date models is appreciated widely enough. Finally, it is considered whether fundamental changes in methodology may help to make transport models more responsive to policy needs.  相似文献   

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