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1.
The energy crisis and various urban problems stemming from auto congestion, pollution, and the cost of providing public highways have created enormous interest in revitalizing our urban mass transit systems. Currently much is being said and written regarding the efficacy of granting federal, state and/or local operating subsidies. In this article, the author reviews the transit industry's peak capacity problem, and questions the economic wisdom of providing operating subsidies, as some are now being provided, and how most will probably be administered in the near future. An alternative plan suggests the manner in which subsidies can eventually help the transit industry. The article concludes with an analysis of what research efforts are needed in many urban transit systems and how subsidies can be used to support such research.  相似文献   

2.
Jakobsson  Cecilia  Fujii  Satoshi  Gärling  Tommy 《Transportation》2002,29(4):349-370
A field experiment was conducted to investigate the effects of economic disincentives on private car use. Eighty two-adult households who were owners of at least one car were randomly assigned to three experimental groups and one control group. Both experimental and control groups logged their car trips during one week before, one week during, and one week after treatment. The treatment consisted of charging two of the experimental groups approximately 100% of normal cost per kilometer of driving during 2 weeks, and charging the third experimental group this amount per kilometer of driving during 4 weeks. With the purpose of investigating whether deliberate planning increases the effect of economic disincentives, the households in one of the former and in the latter group were asked to fill out a prospective car log for the following week. The control group was not charged or requested to fill out a prospective car log but was in other respects treated in the same way. Analyses of the car logs and odometer readings during and at the end of treatment showed a weak reduction of car use due to the economic disincentives that however were almost completely dependent on planning.  相似文献   

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5.
The propensity to travel by rail, and not, for example by car, can be considered to be a factor of the rail service offered, the access to it and the characteristics of the population served. Efforts to increase rail use usually focus on the rail service itself while the accessibility of the rail network receives less attention. In this context, the paper has two broad aims. First, to evaluate how important the ‘access-to-the-station’ part of a rail journey is to passengers in their overall satisfaction with the rail journey and second, to investigate the balance between characteristics of the service, the access to it and the population served in determining rail use in different parts of the rail network. The analysis is carried out for the Netherlands. To achieve the first aim, we use the Dutch Railways customer satisfaction survey and apply principal component analysis and derived importance techniques to assess the relative importance of accessibility in determining the overall satisfaction with the rail journey. For the second aim, we use regression analysis to explain, at the Dutch postcode level, the propensity to use rail. We find that satisfaction with the level and quality of the access to the station is an important dimension of the rail journey which influences the overall satisfaction from that journey and that the quality and level of accessibility is an important element in explaining rail use. The conclusion reached is that in many parts of the rail network improving and expanding access services to the railway station can substitute for improving and expanding the services provided on the rail network and that it is probably more cost efficient when the aim is to increase rail use. These parts of the network are mainly in the periphery where the current level of rail service is relatively low.  相似文献   

6.
Cities promote strong bicycle networks to support and encourage bicycle commuting. However, the application of network science to bicycle facilities is not very well studied. Previous work has found relationships between the amount of bicycle infrastructure in a city and aggregate bicycle ridership, and between microscopic network structure and individual tripmaking patterns. This study fills the missing link between these two bodies of literature by developing a standard methodology for measuring bicycle facility network quality at the macroscopic level and testing its association with bicycle commuting. Bicycle infrastructure maps were collected for 74 Unites States cities and systematically analyzed to evaluate their network structure. Linear regression models revealed that connectivity and directness are important factors in predicting bicycle commuting after controlling for demographic variables and the size of the city. These findings provide a framework for transportation planners and policymakers to evaluate their local bicycle facility networks and set regional priorities that support nonmotorized travel behavior, and for continued research on the structure and quality of bicycle infrastructure and behavior.  相似文献   

7.
Unlimited Access   总被引:1,自引:0,他引:1  
Brown  Jeffrey  Hess  Daniel Baldwin  Shoup  Donald 《Transportation》2001,28(3):233-267
Universities and public transit agencies have together invented an arrangement – called Unlimited Access – that provides fare-free transit service for over 825,000 people. The university typically pays the transit agency an annual lump sum based on expected student ridership, and students simply show their university identification to board the bus. This paper reports the results of a survey of Unlimited Access programs at 35 universities. University officials report that Unlimited Access reduces parking demand, increases students' access to the campus, helps to recruit and retain students, and reduces the cost of attending college. Transit agencies report that Unlimited Access increases ridership, fills empty seats, improves transit service, and reduces the operating cost per rider. Increases in student transit ridership ranged from 71 percent to 200 percent during the first year of Unlimited Access, and growth in subsequent years ranged from 2 percent to 10 percent per year. The universities' average cost for Unlimited Access is $30 per student per year.  相似文献   

8.

Most airlines across Asia are struggling to cope with an unprecedented economic crisis which they have very little control over, and the survival of some remains in doubt. The continuing uncertainty generated by the crisis has accelerated the process of change in the aviation industry and has highlighted the need for adaptability, and its effects have been deeper and longer lasting than previously anticipated. After a year-long slump in the Asian travel market, airlines are now considering a range of options and rehabilitation programmes including a series of cost-cutting measures. There appears to be a trend towards the extension and consolidation of strategic alliances, structural and operational reorganization, and the application of new technologies. The success of these measures will become apparent over time, but action is necessary to minimize the adverse consequences of the crisis which has dominated the region since 1997.  相似文献   

9.
Realistic predictions of the likely safety performance of advanced transport systems will need to draw on the knowledge accumulated from a large number of safety evaluations which have already been undertaken for existing transport systems. In particular, safety evaluations of future technologies must avoid the methodological pitfalls experienced in extensively researched areas, such as road safety, if such evaluations are to be meaningful. This paper reviews the use of exposure for a broad range of road safety studies, and concludes that unsatisfactory treatment of exposure is a common failing in past evaluations of the effectiveness of road accident countermeasures. Whilst a broad range of safety analyses is discussed, the use of exposure in site safety studies is emphasized. A follow-up paper will extend the discussion to other aspects of accident exposure including exposure measures for large groups of transport system users.  相似文献   

10.
The rediscovery of the bicycle by the public, by politicians and by professional urban transportation planners as a mode of transport which is perfectly in harmony with the goals of environmental protection, energy saving and personal fitness has stimulated this empirical study on the actual use of the bicycle by various population groups for obligatory and discretionary trip purposes. The influence on bicycle usage of such factors as age, education, car availability, residential density and town size, topography and time of year is analysed in this paper for selected population groups. For housewives from motorized households logit‐models were designed and calibrated to model their modal choice for shopping trips with special references to the bicycle. From the empirical results, the groups with the largest potentials for cycling are identified and the extent to which the potentials could be activated by specific policies is discussed. The research is based on a large sample held to be representative for the Federal Republic of Germany in 1976 and is supplemented by more recent surveys in selected German cities conducted by SOCIALDATA Munich.  相似文献   

11.
In the research area of dynamic traffic assignment, link travel times can be derived from link cumulative inflow and outflow curves which are generated by dynamic network loading. In this paper, the profiles of cumulative flows are piecewise linearized. Both the step function (SF) and linear interpolation (LI) are used to approximate cumulative flows over time. New formulations of the SF-type and LI-type link travel time models are developed. We prove that these two types of link travel time models ensure first-in-first-out (FIFO) and continuity of travel times with respect to flows, and have other desirable properties. Since the LI-type link travel time model does not satisfy the causality property, a modified LI-type (MLI-type) link travel time model is proposed in this paper. We prove that the MLI-type link travel time model ensures causality, strong FIFO and travel time continuity, and that the MLI-type link travel time function is strictly monotone under the condition that the travel time of each vehicle on a link is greater than the free flow travel time on that link. Numerical examples are set up to illustrate the properties and accuracy of the three models.  相似文献   

12.
We present a dynamic network loading model that yields queue length distributions, accounts for spillbacks, and maintains a differentiable mapping from the dynamic demand on the dynamic queue lengths. The model also captures the spatial correlation of all queues adjacent to a node, and derives their joint distribution. The approach builds upon an existing stationary queueing network model that is based on finite capacity queueing theory. The original model is specified in terms of a set of differentiable equations, which in the new model are carried over to a set of equally smooth difference equations. The physical correctness of the new model is experimentally confirmed in several congestion regimes. A comparison with results predicted by the kinematic wave model (KWM) shows that the new model correctly represents the dynamic build-up, spillback and dissipation of queues. It goes beyond the KWM in that it captures queue lengths and spillbacks probabilistically, which allows for a richer analysis than the deterministic predictions of the KWM. The new model also generates a plausible fundamental diagram, which demonstrates that it captures well the stationary flow/density relationships in both congested and uncongested conditions.  相似文献   

13.
《现代隧道技术》2004,(Z1):12-15
目前正在澳大利亚的悉尼修建一条耗资B.8亿澳元(6.92亿美元)、长12.5km、连接查兹伍德和埃平的地下铁路线,这是新南威尔士历史上最大的市政工程项目之一.就地下施工而言,该工程不仅因规模浩大(25km的区间隧道大直径的TBM开挖)令人难忘,而且隧道的掘进速度也令人注目.目前,两台直径为7.2m的罗宾斯TBM中的一台正以每周高达200m的速度穿入隧道定线所处的Hawkesbury砂岩地层!  相似文献   

14.
Transport infrastructure and regional economic growth: evidence from China   总被引:1,自引:0,他引:1  
This article develops a multi-dimensions measurement of transport infrastructure and examines the linkage between transport infrastructure and regional economic growth. A panel data model is estimated using data from a sample of 31 Chinese provinces from 1998 to 2007. The results provide strong evidence that transport infrastructure plays an important role in economic growth. Both land transport and water transport infrastructure have strong and significant impacts, while the contribution of airway transport infrastructure is weak. Furthermore, land transport infrastructure contributes more to economic growth in locations with poor land transport infrastructure, while the investment in water transport infrastructure contribute positively to economic growth only after the investment scale exceeds a threshold level. These results are robust to a variety of alternative methods, the exclusion of possible outliers, and consideration of endogeneity. A retrospective analysis shows that uneven distribution of transport infrastructure is an important reason behind economic disparities across Chinese regions.  相似文献   

15.
Breaking car use habits: The effectiveness of a free one-month travelcard   总被引:1,自引:0,他引:1  
Based on calls for innovative ways of reducing car traffic and research indicating that car driving is often the result of habitual decision-making and choice processes, this paper reports on a field experiment designed to test a tool aimed to entice drivers to skip the habitual choice of the car and consider using—or at least trying—public transport instead. About 1,000 car drivers participated in the experiment either as experimental subjects, receiving a free one-month travelcard, or as control subjects. As predicted, the intervention had a significant impact on drivers’ use of public transport and it also neutralized the impact of car driving habits on mode choice. However, in the longer run (i.e., four months after the experiment) experimental subjects did not use public transport more than control subjects. Hence, it seems that although many car drivers choose travel mode habitually, their final choice is consistent with their informed preferences, given the current price–quality relationships of the various options.  相似文献   

16.
经济运距是从道路、车辆和组织管理等方面综合反映运输能力的技术经济指标,是适宜道路客运车辆的最佳运行效益和最佳运行状态.  相似文献   

17.
The end of the cold war and confrontational politics of the eastern and western worlds have raised the possibility that resources formerly targeted toward military systems and options may be turned towards global lifestyle improvements [OTA, 1993]. Transportation has been one of the fields proposed as a likely candidate for both improvements and jobs. It is not possible to address economic development in the context of all transportation in one essay. For this reason I am only addressing the issues of economic development associated with mass transportation characteristic of urban and interurban environments. Realigning former defense resources to mass transit requires careful consideration of market conditions. According to economic survey data published by the Economic Roundtable in Los Angeles, there are currently less than 40,000 manufacturing jobs in the U.S. rail transportation industry [Drayse, 1993]. The same survey pointed out a severe mismatch between the skill base required by the rail industry and available defense technology resources. There exists no large base of unsatisfied demand in the rail market, therefore development of a large number of jobs is not likely if the approach is simply to introduce additional competing resources into a traditional market [Monitor, 1993].  相似文献   

18.
Passing from path flows to link flows requires non-linear and complex flow propagation models known as network loading models. In specific technical literature, different approaches have been used to study Dynamic Network Loading models, depending on whether the link performances are expressed in an aggregate or disaggregate way, and how vehicles are traced. When vehicle movements are traced implicitly and link performances are expressed in an aggregate way, the approach is macroscopic. When vehicle movements are traced explicitly, two cases are possible, depending on whether link performances are expressed in a disaggregate or aggregate way. In the first case, the approach is microscopic, otherwise it is mesoscopic.In this paper, a mesoscopic Dynamic Network Loading model is considered, based on discrete packets and taking into account the vehicle acceleration and deceleration. A simulation was carried out, first using theoretical input data to simulate over-saturation condition, and then real data to validate the model. The results show that the model appears realistic in the representation of outflow dynamics and is quite easy to calculate. It is worth noting that network loading models are usually used downstream of the assignment models from which they take path flows to calculate link flows. In the above mentioned simulation, we assumed that a generic assignment model provides sinusoidal path flow.  相似文献   

19.
An access control policy that eliminates all queues beyond the entry points to a network has obvious benefits, which include smooth travel and predictable travel times inside the network. Yet it has never been proven, to the best of our knowledge, whether excluding inside queues yields sub-optimal network performance or, in other words, allowing inside queues can actually further reduce the system travel cost. Moreover, it is not clear whether an optimal control policy derived from efficiency considerations can also be a fair policy to all road users. This paper provide answers to these questions in the context of a monocentric network. By analyzing the structure of the access control problem considering all feasible policies (with/without inside queues), we show that the minimal system cost realizable by access control can be obtained without directly solving a non-convex optimization program, and can indeed always be achieved by a control policy excluding all of the inside queues. These optimal policies are defined by a polyhedral set and a Finite Generation Algorithm can be applied to derive the analytical form of this set. The optimal policies are not unique in general, thus making it possible to achieve both minimal system cost and fairness simultaneously.  相似文献   

20.
Robust public transport networks are important, since disruptions decrease the public transport accessibility of areas. Despite this importance, the full passenger impacts of public transport network vulnerability have not yet been considered in science and practice. We have developed a methodology to identify the most vulnerable links in the total, multi-level public transport network and to quantify the societal costs of link vulnerability for these identified links. Contrary to traditional single-level network approaches, we consider the integrated, total multi-level PT network in the identification and quantification of link vulnerability, including PT services on other network levels which remain available once a disturbance occurs. We also incorporate both exposure to large, non-recurrent disturbances and the impacts of these disturbances explicitly when identifying and quantifying link vulnerability. This results in complete and realistic insights into the negative accessibility impacts of disturbances. Our methodology is applied to a case study in the Netherlands, using a dataset containing 2.5 years of disturbance information. Our results show that especially crowded links of the light rail/metro network are vulnerable, due to the combination of relatively high disruption exposure and relatively high passenger flows. The proposed methodology allows quantification of robustness benefits of measures, in addition to the costs of these measures. Showing the value of robustness, our work can support and rationalize the decision-making process of public transport operators and authorities regarding the implementation of robustness measures.  相似文献   

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