Waiting Time Cost Research Articles

Shuttle Planning for Link Closures in Urban Public Transport Networks

Urban public transport systems must periodically close certain links for maintenance, which can have significant effects on the service provided to passengers. In practice, the effects of closures are mitigated by replacing the closed links with a simple shuttle service. However, alternative shuttle services could reduce inconvenience at a lower operating cost. This paper proposes a model to select shuttle lines and frequencies under budget constraints. We propose a new formulation that allows a minimal frequency restriction on any line that is operated and minimizes passenger inconvenience cost, which includes transfers and frequency-dependent waiting time costs. This model is applied to a shuttle design problem based on a real-world case study of the Massachusetts Bay Transportation Authority network of Boston, Massachusetts. The results show that additional shuttle routes can reduce passenger delay compared to the standard industry practice, while also distributing delay more equally over passengers, at the same operating budget. The results are robust under different assumptions about passenger route choice behavior. Computational experiments show that the proposed formulation, coupled with a preprocessing step, can be solved faster than prior formulations.

The Optimization Model and Algorithm for Train Connection at Transfer Stations in Urban Rail Transit Network

In urban rail transit network, the passenger transfer time depends on the train connection states in transfer sta- tions, so the optimization of the connection relations of arrival and departure time among trains is significant to improve the level of transfer service. Here, with the psychology of waiting passengers taken into consideration, the cost function of transfer waiting times has been established. On this basis, an optimization model for train connections at transfer stations was constructed, and a genetic algorithm was designed to solve this model. A computer program implementing this ge- netic algorithm was written in Microsoft VB.NET. And the program is used to optimize the train operation plans of a sim- ple network which consists of four urban rail lines in Beijing. The results show that the proposed method can effectively reduce the total waiting time cost of all transfer passengers in the network.

Traditional vs. non-traditional healing for minor and major morbidities in India: uses, cost and quality comparisons.

To examine the uses, cost and quality of care of traditional healing for short-term morbidities and major morbidities in India and to compare them with the non-traditional healing. We used data from a nationally representative survey, the India Human Development Survey (2004-2005) and descriptive as well as bivariate analyses for the examination. Use of traditional healing is much less common than use of non-traditional healing in both rural and urban areas and across all socio-economic and demographic characteristics; it is slightly more common in rural than urban areas for short-term morbidities. Use of traditional healing is relatively more frequent for cataract (especially in rural areas), leprosy, asthma, polio, paralysis, epilepsy and mental illnesses; its total cost of care and mean waiting time (in the health facility) are substantially lower than for non-traditional healing. Among patients who use both traditional and non-traditional healing, a relatively higher proportion use traditional healing complemented by non-traditional healing for short-term illnesses, but vice versa for major morbidities. This is the first study which has investigated at the national level the uses, complementarities, cost and quality aspects of traditional and non-traditional healing in India. Traditional healing is more affordable and pro-poor. Relatively higher use of traditional healing in patients from poorly educated as well as poor households and suffering from diseases, such as, epilepsy and mental illnesses; and higher demand for traditional healing for the above diseases highlight the need for research/policy reorientation in India.

A stochastic optimization model for transit network timetable design to mitigate the randomness of traveling time by adding slack time

Transit network timetabling aims at determining the departure time of each trip of all lines in order to facilitate passengers transferring either to or from a bus. In this paper, we consider a bus timetabling problem with stochastic travel times (BTP-STT). Slack time is added into timetable to mitigate the randomness in bus travel times. We then develop a stochastic integer programming model for the BTP-STT to minimize the total waiting time cost for three types of passengers (i.e., transferring passengers, boarding passengers and through passengers). The mathematical properties of the model are characterized. Due to its computational complexity, a genetic algorithm with local search (GALS) is designed to solve our proposed model (OPM). The numerical results based on a small bus network show that the timetable obtained from OPM reduces the total waiting time cost by an average of 9.5%, when it is tested in different scenarios. OPM is relatively effective if the ratio of the number of through passengers to the number of transferring passengers is not larger than a threshold (e.g., 10 in our case). In addition, we test different scale instances randomly generated in a practical setting to further verify the effectiveness of OPM and GALS. We also find that adding slack time into timetable greatly benefits transferring passengers by reducing the rate of transferring failure.

교통카드 데이터를 이용한 버스 승객 대기시간 최소화 알고리즘 개발

Bus headway plays an important role not only in determining the passenger waiting time and bus service quality, but also in influencing the bus operation cost and passenger demand. Previous research on headway control has considered only an hourly difference in the distribution of ridership between peak and non-peak hours. However, this approach is too simple to help manage ridership demand fluctuations in a short time scale; thus passengers’ waiting cost will be generated when ridership demand exceeds the supply of bus services. Moreover, bus ridership demand varies by station location and traffic situation. To address this concern, we propose a headway control algorithm for minimizing the waiting time cost by using Smart Card data. We also provide proof of the convergence of the algorithm to the desired headway allocation using a set of preconditions of political waiting time guarantees and available fleet constraints. For model verification, the data from the No. 143 bus line in Seoul were used. The results show that the total savings in cost totaled approximately 600,000 won per day when we apply the time-value cost of waiting time. Thus, we can expect that cost savings will be more pronounced when the algorithm is applied to larger systems.

A two level metaheuristic for the operating room scheduling and assignment problem

Given a surgery department comprising several specialties that share a fixed number of operating rooms and post-surgery beds, we study the joint operating room (OR) planning and advanced scheduling problem. More specifically, we consider the problem of determining, over a one week planning horizon, the allocation of OR time blocks to specialties together with the subsets of patients to be scheduled within each time block. The aim of this paper is to extend and generalize existing approaches for the joint OR planning and scheduling problem. First, by allowing schedules that include patients requiring weekend stay beds which was not the case previously. Second, by tackling simultaneously both the OR planning and patient scheduling decision levels, instead of taking them into account in successive phases. To achieve this, we exploit the inherent hierarchy between the two decision levels, i.e.,the fact that the assignment decisions of OR time blocks to surgical specialties directly affect those regarding the scheduling of patients, but not the reverse. The objective function used in this study is an extension of an existing one. It seeks to optimize both patient utility (by reducing waiting time costs) and hospital utility (by reducing production costs measured in terms of the number of weekend stay beds required by the surgery planning). 0–1 linear programming formulations exploiting the stated hierarchy are proposed and used to derive a formal proof that the problem is NP-hard. A two level metaheuristic is then developed for solving the problem and its effectiveness is demonstrated through extensive numerical experiments carried out on a large set of instances based on real data.

Partially entangled states bridge in quantum teleportation

The traditional method for information transfer in a quantum communication system using partially entangled state resource is quantum distillation or direct teleportation. In order to reduce the waiting time cost in hop-by-hop transmission and execute independently in each node, we propose a quantum bridging method with partially entangled states to teleport quantum states from source node to destination node. We also prove that the designed specific quantum bridging circuit is feasible for partially entangled states teleportation across multiple intermediate nodes. Compared to two traditional ways, our partially entanglement quantum bridging method uses simpler logic gates, has better security, and can be used in less quantum resource situation.

Optimization Model for Headway of a Suburban Bus Route

Due to relatively low passenger demand, headways of suburban bus route are usually longer than those of urban bus route. Actually it is also difficult to balance the benefits between passengers and operators, subject to the service standards from the government. Hence the headway of a suburban bus route is usually determined on the empirical experience of transport planners. To cope with this problem, this paper proposes an optimization model for designing the headways of suburban bus routes by minimizing the operating and user costs. The user costs take into account both the waiting time cost and the crowding cost. The feasibility and validity of the proposed model are shown by applying it to the Route 206 in Jiangning district, Nanjing city of China. Weightages of passengers’ cost and operating cost are further discussed, considering different passenger flows. It is found that the headway and objective function are affected by the weightages largely.

Superando el síndrome del "enemigo externo" en una firma autopartista a través del kaizen

Dos problemas de una firma autopartista, con causas atribuidas inicialmente a factores externos no controlables (síndrome del "enemigo externo"), motivan el uso del kaizen, incorporando concepciones filosóficas y metodológicas. La metodología propuesta consta de tres etapas; la primera, iniciar, pretende conducir hacia el compromiso, la participación y el desarrollo de habilidades iniciales de los empleados; luego sigue desarrollar, que ejecuta el análisis y la solución del problema; se culmina con sostener, para mantener las contramedidas, evitar la recurrencia del problema e incentivar a los participantes. Al desplegar la metodología en los dos casos objeto de estudio (1. Muda de espera por falta de suministro y 2. Muda de defectos de hojas impresas), se identificó que las causas de dichos muda se debieron a factores internos a la empresa y no a las creencias iniciales de la firma sobre aspectos externos, no controlables. La causa del muda de espera estuvo relacionada con la cantidad de personal programado en la línea de ensamble; las impresiones defectuosas se asociaron a la política de almacenaje y protección de las hojas, así como a las instrucciones de impresión. El impacto del despliegue en la empresa se dedujo satisfactorio, ya que mediante la implantación de contramedidas basadas en creatividad, sentido común, consenso y participación de los empleados, se favorecen indicadores asociados a los problemas precisos, entre ellos, costos anuales de los muda (reducción: 87% en costos del muda de espera y 60,5% en costos de hojas defectuosas). Este trabajo provee elementos teóricos y metodológicos, que posibilitan la adaptación a otros contextos, exigiendo: compromiso directivo, justificación del cambio, entrenamiento de empleados, incentivos, comunicación y estrategias de aprendizaje, entre otros, para solucionar problemas y sostener los eventos kaizen.

Expected value model for optimizing the multiple bus headways

This paper studies the optimal multiple headways determination for a single bus route with a stochastic expected value model. The stochastic events from the model consist of random passenger arrivals, random boarding/alighting as well as random bus travel time. The expected value model employs two objective functions to maximize the bus company profit and to minimize the passengers waiting time cost respectively. The model is solved by a hybrid intelligent algorithm in which stochastic simulation and genetic algorithm are used to treat with the uncertain function. The algorithm efficiency is tested by a numerical experiment and concerned conclusions are drawn.

Delay Adjustment Method at Transfer Station of High-Speed Railway

Passenger transfer is one of the important research contents after the network operation of high-speed railway. Due to the high operation speed and high frequency, delays at transfer stations may occur frequently, leading to some potential safety problems. Main influence factors such as schedule time, transfer buffer time, waiting time, and delay time of delay and passengers classification during transfer were analyzed. A delay adjustment model of passengers at a transfer station was presented with minimal delay cost, waiting time cost, and adjustment cost as the optimization goal. Two adjustment strategies were proposed, including transfer passengers departure time adjustment and connecting trains departure time adjustment. And a delay adjustment algorithm at transfer station was designed for the optimal adjustment scheme. A case study proves the effectiveness of the method on optimal scheme design for passengers transferbased on the lowest delay cost of all passengers.

Analysis of Light Rail Access to Airports for the Effective Ground Transportation

This paper discusses the attractiveness the cost-effectiveness of the light rail service connecting the airport and the main destinations in a city compared with other modes of ground transportation. A mathematical model is developed and the optimal frequency of light rail service is decided based on the minimization of the total cost including waiting time cost of travelers at the airport and operating cost of the light rail. Sensitivity analysis is made to show the effect of such parameters as passenger flow, unit time cost, unit operating time cost and etc. on the optimal frequency of the light rail service to provide the convenient, cost-effectiveness, and advanced accessible ground transportation service at the airport.

Simulation model to determine frequency of a single bus route with single and multiple headways

Determination of frequency is one of the important elements of bus transit system design. In the past, the researchers have used the average passenger demand and average travel time (deterministic data) as input in their models to find the frequency of buses in a selected route. In practice, the arrival of passengers at the stages and travelling time between stages is stochastic in nature. So, the frequency determination under deterministic conditions may not yield good results. In this paper, the stochastic nature of passenger arrival at the stages and travelling time between stages is considered. A simulation model is built using ARENA version 12, a discrete simulation software package to arrive at the solution. The best frequency is determined for the selected route so as to minimise the total cost comprising the waiting time cost of the passengers and operating cost of the buses with single and multiple headways. The model has been applied to one of the bus routes in Chennai City (a metropolitan city ...

Analysis of Light Rail Access to Airports for the Effective Ground Transportation

This paper discusses the attractiveness the cost-effectiveness of the light rail service connecting the airport and the main destinations in a city compared with other modes of ground transportation. A mathematical model is developed and the optimal frequency of light rail service is decided based on the minimization of the total cost including waiting time cost of travelers at the airport and operating cost of the light rail. Sensitivity analysis is made to show the effect of such parameters as passenger flow, unit time cost, unit operating time cost and etc. on the optimal frequency of the light rail service to provide the convenient, cost-effectiveness, and advanced accessible ground transportation service at the airport.Request access from your librarian to read this article's full text.

An integrated approach for optimal rail transit corridor identification and scheduling using geographical information system

In this work an integrated approach has been proposed to identify and schedule a rail transit corridor in a city which has a potential demand for a new rail based mass transit system besides the street transit system and existing rail-based system (if any). The motivation for the present study comes from the present Indian context where, because of recent initiatives of Central Urban Development Ministry, many Urban Local Bodies (ULBs) and transit agencies need to master plan new rail based systems in an optimum way and at the same time attempting to integrate them with other existing public transport (PT) modes. While aligning the new rail transit system, the primary focus of the integrated approach is to optimize the origin–destination (O–D) travel time of the user and at the same time attempting to minimize the operators’ cost. The proposed rail corridor identification model consists of three stages: public transport demand forecasting, creation of corridor link set, and optimization of rail corridor using Geographical Information System (GIS). The objective function for train scheduling model is fixed as minimization of sum of operating cost of trains (operator cost) and total waiting time cost of passengers boarding the train (user costs) subject to load factor and waiting time constraints. The dwell time of train at stations, which is usually considered constant, has been taken as a variable which depends on the actual number of passengers boarding and alighting the train. The model is applied on Thane municipal corporation (TMC) area, a major urban center of the Mumbai metropolitan region (MMR), India. The maximum peak hour ridership obtained on the identified corridor was found to be ideal for recommending light-rail transit system (LRT). The successful application of the model shows the capability of proposed model for a typical Indian city, which has potential demand for a new rail system.

Equilibria of bilateral taxi–customer searching and meeting on networks

This paper proposes an equilibrium model to characterize the bilateral searching and meeting between customers and taxis on road networks. A taxi driver searches or waits for a customer by considering both the expected searching or waiting time cost and ride revenue, and a customer seeks a taxi ride to minimize full trip price. We suppose that the bilateral taxi–customer searching and meeting occurs anywhere in residential and commercial zones or at prescribed taxi stands, such as an airport or a railway station. We propose a meeting function to spell out the search and meeting frictions that arise endogenously as a result of the distinct spatial feature of the area and the taxi–customer moving decisions. With the proposed meeting function and the assumptions underlying taxi–customer search behaviors, the stationary competitive equilibrium achieved at fixed fare prices is determined when the demand of the customers matches the supply of taxis or there is market clearing at the prevailing searching and waiting times in every meeting location. We establish the existence of such an equilibrium by virtue of Brouwer’s fixed-point theorem and demonstrate its principal operational characteristics with a numerical example.

Comparing operator and users costs of light rail, heavy rail and bus rapid transit over a radial public transport network

A model to compare three alternative forms of public transport – light rail, heavy rail and bus rapid transit - is developed for an urban network with radial lines emanating from the borders to the city centre. The theoretical framework assumes an operation aimed at minimising the total cost associated with public transport service provision, which encompasses both operator and users costs. The decision variables are the number of lines (network density) and the frequency per period for each mode. This approach has no prejudices a priori in respect of whether a specified delivery scenario is aligned with existing modal reputation. Rather, we establish the conditions under which a specific transit mode should be preferred to another in terms of the operator (supply) and user (demand) side offerings. The model is applied using data from Australian cities, suggesting that in most of the scenarios analysed a high standard bus service is the most cost-effective mode, because it provides lower operator costs (infrastructure, rolling stock and operating cost), access time costs (due to a larger number of lines) and waiting time cost (due to larger frequencies of operation). A rail mode, such as light rail or heavy rail, may have a lower total cost only if it is able to run faster than bus rapid transit, and the difference in speed is enough to outweigh the bus advantage on operator cost and access and waiting times.

Models and internals of the IANOS resource broker

We present the Intelligent Application Oriented System (IANOS) resource broker models and internals. The aim of IANOS is to provide an understanding of and a solution to the problem of how to find the best resource for a given submitted application in order to optimally use a set of HPC resources (an HPCN Grid). Best in the sense “at a given moment and for the requirements of that specific application”. The heart of IANOS is a cost model that minimizes the overall submission cost such as execution time cost, waiting time cost, licenses cost, energy cost, etc. To estimate the execution time cost, a model predicting the performance of an application on a resource where INAOS is installed is provided. This model is based on a parameterization of the application and the resources. IANOS has been deployed and tested successfully on an international testbed across Switzerland and Germany.

The marginal social cost of headway for a scheduled service

This brief paper derives the marginal social cost of headway for a scheduled service, i.e. the cost for users of marginal increases to the time interval between departures. In brief we may call it the value of headway in analogy with the value of travel time and the value of reliability. Users have waiting time costs as well as schedule delay costs measured relative to their desired time of arrival at the destination. They may either arrive at the station to choose just the next departure or they may plan for a specific departure in which case they incur also a planning cost. Then planning for a specific departure is costly but becomes more attractive at longer headways. Simple expressions for the user cost result. In particular, the marginal cost of headway is large at short headways and smaller at long headways. The difference in marginal costs is the value of time multiplied by half the headway.

Third degree waiting time discrimination: optimal allocation of a public sector healthcare treatment under rationing by waiting

In many public healthcare systems treatments are rationed by waiting time. We examine the optimal allocation of a fixed supply of a given treatment between different groups of patients. Even in the absence of any distributional aims, welfare is increased by third degree waiting time discrimination: setting different waiting times for different groups waiting for the same treatment. Because waiting time imposes dead weight losses on patients, lower waiting times should be offered to groups with higher marginal waiting time costs and with less elastic demand for the treatment.