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1.
This study evaluates an existing bus network from the perspectives of passengers, operators, and overall system efficiency using the output of a previously developed transportation network optimisation model. This model is formulated as a bi-level optimisation problem with a transit assignment model as the lower problem. The upper problem is also formulated as bi-level optimisation problem to minimise costs for both passengers and operators, making it possible to evaluate the effects of reducing operator cost against passenger cost. A case study based on demand data for Hiroshima City confirms that the current bus network is close to the Pareto front, if the total costs to both passengers and operators are adopted as objective functions. However, the sensitivity analysis with regard to the OD pattern fluctuation indicates that passenger and operator costs in the current network are not always close to the Pareto front. Finally, the results suggests that, regardless of OD pattern fluctuation, reducing operator costs will increase passenger cost and increase inequity in service levels among passengers.  相似文献   

2.
Safe and reliable coupling and decoupling of cars from a moving train is feasible with further developments in linear motor propulsion and control of transit vehicles. This allows the last car of a train to decouple and stop at a station for a relative long dwell time, before it accelerates and is coupled to a following train. Controlled doors in front and rear of the transit vehicle permit passengers to walk through the train to the car which stops at their destination. A proposed transit system using these features is described and compared to Bombardier's Advanced Rapid Transit. Potential advantages are high schedule speed, uncrowded trains, smaller and more stations, low energy requirements and a smaller vehicle fleet.  相似文献   

3.
4.
Conventionally, the objective of transit routing is often set either to minimize the total operational cost, subject to a given level of service quality, or to maximize the service quality at a given acceptable cost. In a deregulated, commercial‐based environment however, such as bus and railway operations in cities of the UK and Hong Kong where several private firms compete in route‐based or area‐based market, routing becomes one of the means for higher returns rather than just for cost saving. In such a case, how do the transit providers set up their routes for profit‐maximization? Will the routing based on the provider's objective meet the user's objective? How do government regulations and policies affect the choice of transit provider's routing strategy? To answer these questions, we first examine the relationship between the objectives of users and transit providers, set up criteria for transit routing quality, and then investigate the possible routing configurations/patterns for a hypothetical case. These criteria include (1) the load factor of transit, (2) the level of route directness, (3) the level of route overlapping, and (4) the total number of routes and (5) the average of route length. These measures are finally applied to a real case in Hong Kong to examine the route changes of Kowloon Motor Bus from 1975 to 1995. The result of the empirical case reveais how key measures such as load factor are controlled by the bus operator and affected by government policies and how the bus routing pattern was adjusted to meet users' need. Facing the dilemma as evident in Hong Kong between the route directness and the efficiency of road use, we suggest that a rational multi‐modal routing structure be put in place if an institutional solution is introduced so that bus and other transit modes can form a sharing program or an alliance.  相似文献   

5.
As the problem of full transit vehicles is encountered daily by passengers in most of the big cities, previous research evaluated the consequence of overcrowding in terms of on‐board crowding and passengers not being able to board with full vehicles. The impact of overcrowding in the real world is, however, not necessarily proportional to these numbers. This paper attempts to specify the critical lines and stations of a network by considering the number of passengers failing to board and attempting to evaluate its impact on service quality and safety risks. The hypothesis is that larger stations with wider platforms can often cope better with overcrowding than smaller stations. Therefore a station size dependent satisfaction function is proposed, which takes values from 0 to 1. The method is applied to London's underground network with a number of scenarios which show critical stations in the network if delays occur.  相似文献   

6.
This paper presents and tests a method to design high-performance transit networks. The method produces conceptual plans for geometric idealizations of a particular city that are later adapted to the real conditions. These conceptual plans are generalizations of the hybrid network concept proposed in Daganzo (2010). The best plan for a specific application is chosen via optimization. The objective function is composed of analytic formulae for a concept’s agency cost and user level of service. These formulae include as parameters key demand-side attributes of the city, assumed to be rectangular, and supply-side attributes of the transit technology. They also include as decision variables the system’s line and stop spacings, the degree to which it focuses passenger trips on the city center, and the service headway. These decision variables are sufficient to define an idealized geometric layout of the system and an operating plan. This layout-operating plan is then used as a design target when developing the real, detailed master plan. Ultimately, the latter is simulated to obtain more accurate cost and level of service estimates.This process has been applied to design a high performance bus (HPB) network for Barcelona (Spain). The idealized solution for Barcelona includes 182 km of one-way infrastructure, uses 250 vehicles and costs 42,489 €/h to build and run. These figures only amount to about one third of the agency resources and cost currently used to provide bus service. A detailed design that resembles this target and conforms to the peculiarities of the city is also presented and simulated. The agency cost and user level of service metrics of the simulated system differ from those of the idealized model by less than 10%. Although the designed and simulated HPB systems provide sub-optimal spatial coverage because Barcelona lacks suitable streets, the level of service is good. Simulations suggest that if the proposed system was implemented side-by-side with the current one, it would capture most of the demand.  相似文献   

7.
Zhu  Yi 《Transportation》2020,47(6):2703-2730
Transportation - Understanding individual daily activity patterns is essential for travel demand management and urban planning. This research introduces a new method to infer transit riders’...  相似文献   

8.
In this paper we examine the transit network design problem under the assumption of elastic demand, focusing on the problem of designing the frequencies of a regional metro. In this problem, investments in transit services have appreciable effects on modal split. Neglecting demand elasticity can lead to solutions that may not represent the actual objectives of the design. We propose four different objective functions that can be adopted to assume demand as elastic, considering the costs of all transportation systems (car, bus and rail) as well as the external costs, and we define the constraints of the problem. Heuristic and meta-heuristic solution algorithms are also proposed. The models and algorithms are tested on a small network and on a real-scale network.  相似文献   

9.
Mass transit projects are often a top contender of many cities to meet their increasing demand for travel. Despite the global trend of privatization, mass transit services, as public goods, remain largely being provided and operated by the public sector. Hong Kong is one of the few exceptions that all mass transit services are commercially operated. Both rail and bus services in Hong Kong are reputable for their quality and profitability, often serving as benchmarks for new projects. In this study, we investigate the factors contributing to this success. In particular, we ascertain the quality of transit service provision by the private sector over the past two decades. Then, we conduct an in-depth analysis of the account books of leading railway and bus operators in Hong Kong so as to shed light on their financial viability. Through this study, we hope to present crucial factors for providing financially viable private transit services.  相似文献   

10.
Traditionally, an assessment of transport network vulnerability is a computationally intensive operation. This article proposes a sensitivity analysis-based approach to improve computational efficiency and allow for large-scale applications of road network vulnerability analysis. Various vulnerability measures can be used with the proposed method. For illustrative purposes, this article adopts the relative accessibility index (AI), which follows the Hansen integral index, as the network vulnerability measure for evaluating the socio-economic effects of link (or road segment) capacity degradation or closure. Critical links are ranked according to the differences in the AIs between normal and degraded networks. The proposed method only requires a single computation of the network equilibrium problem. The proposed technique significantly reduces computational burden and memory storage requirements compared with the traditional approach. The road networks of the Sioux Falls city and the Bangkok metropolitan area are used to demonstrate the applicability and efficiency of the proposed method. Network manager(s) or transport planner(s) can use this approach as a decision support tool for identifying critical links in road networks. By improving these critical links or constructing new bypass roads (or parallel paths) to increase capacity redundancy, the overall vulnerability of the networks can be reduced.  相似文献   

11.
We present an approach to systematically analysing the vulnerability of road networks under disruptions covering extended areas. Since various kinds of events including floods, heavy snowfall, storms and wildfires can cause such spatially spread degradations, the analysis method is an important complement to the existing studies of single link failures. The methodology involves covering the study area with grids of uniformly shaped and sized cells, where each cell represents the extent of an event disrupting any intersecting links. We apply the approach to the Swedish road network using travel demand and network data from the Swedish national transport modelling system Sampers. The study shows that the impacts of area-covering disruptions are largely determined by the level of internal, outbound and inbound travel demand of the affected area itself. This is unlike single link failures, where the link flow and the redundancy in the surrounding network determine the impacts. As a result, the vulnerability to spatially spread events shows a markedly different geographical distribution. These findings, which should be universal for most road networks of similar scale, are important in the planning process of resource allocation for mitigation and recovery.  相似文献   

12.
Kim  Ikki  Kim  Hyoung-Chul  Seo  Dong-Jeong  Kim  Jung In 《Transportation》2020,47(5):2179-2202
Transportation - One of the major objectives of this study is to provide more realistic and accurate results related to transit passenger’s route choice behavior by using population data of...  相似文献   

13.
This research focuses on an efficient design of transit network in urban areas. The system developed is used to create, analyze and optimize routes and frequencies of transit system in the network level. The analysis is based on elastic demand, so the shift of demand between modes in network due to different service level is of prime consideration. The developed system creates all feasible routes connecting all pairs of terminals in the network. Out of this vast pool of routes, a set of optimal routes is generated for a certain predetermined number that maintains connectivity of significant demand. Based on these generated routes, the system fulfils transportation demand by assigning demand that considers path and route choices for non-transit users and transit users. Together with the assignment of demand, transit frequencies are optimized and the related fleet-size is calculated. Having an optimal setting of solution, the system is continued by reconnecting the routes to find some other better solutions in the periphery of the optimal setting. A set of mathematical programming modules is developed. Real data from Sioux Falls city network is used to evaluate the performance of the model and compare with other heuristic methods.  相似文献   

14.
To improve the efficiency of large-scale evacuations, a network aggregation method and a bi-level optimization control method are proposed in this paper. The network aggregation method indicates the uncertain evacuation demand on the arterial sub-network and balances accuracy and efficiency by refining local road sub-networks. The bi-level optimization control method is developed to reconfigure the aggregated network from both supply and demand sides with contraflow and conflict elimination. The main purpose of this control method is to make the arterial sub-network to be served without congestion and interruption. Then, a corresponding bi-objective network flow model is presented in a static manner for an oversaturated network, and a Genetic Algorithm-based solution method is used to solve the evacuation problem. The numerical results from optimizing a city-scale evacuation network for a super typhoon justify the validity and usefulness of the network aggregation and optimization control methods.  相似文献   

15.
Chan  Kevin  Farber  Steven 《Transportation》2020,47(5):2157-2178
Transportation - Encouraging the integration of active transportation with transit is increasingly being pursued as a strategy by transit agencies to boost alternative means to access transit...  相似文献   

16.
Zhang  Yixue  Farber  Steven  Young  Mischa 《Transportation》2022,49(5):1385-1408
Transportation - Demand-responsive technologies are rapidly changing the transportation landscape. The City of Belleville, Ontario has recently replaced its evening and nighttime fixed route bus...  相似文献   

17.
We evaluate the economic effects of investment in the road network on private regional activity. We employ provincial Spanish panel data from 1980 to 2007 to perform non-parametric frontier techniques based on Data Envelopment Analysis and to obtain the Malmquist productivity indexes, thus enabling us to examine the evaluation of the productivity growth via technological changes or efficiency gains. Additionally, we analyze the role of transport infrastructure on the evolution of Total Factor Productivity and its components through econometric techniques. Our results show important spillover effects. Moreover, our findings have significant implications for policy makers if we take into account the fact that the use of the road network in economic activity or in commercial relations greatly influences productivity growth.  相似文献   

18.
The trend toward public ownership, public regulation, and public subsidization of the U.S. transit industry has recently come under attack. Many argue that the result has been reduced productivity, increased costs, and very little real benefit. This article examines the impacts of subsidies and public ownership in four large transit systems that cover a range of transit system types and financing arrangements. Evidence from the case studies is compared to the results of both time-series and cross-section regression analysis of operating and financial statistics for large samples of bus systems. Although the case studies and the regressions rely on different datasets and different techniques, they support the same conclusions. Increased subsidies and public ownership have kept down fares and permitted service expansion, but have also encouraged wasteful cost escalation. Thus, transit riders unquestionably have benefited from public takeovers of transit systems and burgeoning subsidies, but not nearly as much as they would have benefited if costs had not skyrocketed at the same time.  相似文献   

19.
The paper presents a comprehensive investigation on household level commuting mode, car allocation and car ownership level choices of two-worker households in the City of Toronto. A joint econometric model and a household travel survey dataset are used for empirical investigations. Empirical models reveal that significant substitution patterns exist between auto driving and all other mode choices in two-worker households. It is revealed that, female commuters do not prefer auto driving, but in case of a one car (and two commuters with driving licenses) household, a female commuter gets more preference for auto driving option than the male commuter. Reverse commuting (commuting in opposite direction of home to central business district) plays a critical role on household level car allocation choices and in defining the stability of commuting behaviour of two-worker households. Two worker households in higher income zones and with longer commuting distances tend to have higher car ownership levels than others. However, higher transit accessibility to jobs reduces household car ownership levels. The study reveals that both increasing two worker households and reverse commuting would increase dependency on private car for commuting.  相似文献   

20.
Li  Jianling  Wachs  Martin 《Transportation》2004,31(1):43-67
In the United States, federal funding for public transit often accounts for a large proportion of a local agency's budget, especially for capital investments. For this reason, local governments can be expected to plan a portfolio of projects that maximize federal contributions. This study examines the financial effects of federal transit subsidy policy on local transit investment decisions. Data from a System Planning Study for the Geary Corridor in San Francisco are used as an illustration. It is found that federal transit subsidy policy provides financial incentives for local decision-makers to select capital-intensive investment options that may not be efficient or effective. While federal financial incentives are not the only factor influencing local investment decisions, some reform of the current subsidy policy may be necessary to reduce the incentive for ineffective use of public resources.  相似文献   

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