The time-dependent O-D demands are critical to the success of Dynamic Traffic Assignment (DTA) in Advanced Traffic Management Systems (ATMS). This study aims at constructing an assignment-based dynamic O-D estimation and predictions model and examining the process through the empirical data. Based on Ashoks idea, the implemented model takes the deviations of O-D flows from historical averages instead of O-D flows as the state vector to increase the accuracy of estimations. Several unique features proposed in this research include: (1) implementation of MySQL database, and (2) the time-dependent assignment matrix is obtained through a simulation-assignment model, DynaTAWIAN. The numerical experiments are based on a real Kaoshung City network. The results show high agreements between actual flows from vehicle detectors and simulated flows from DynaTAWIAN.

抄録全体を表示

This paper applies the concept of price of anarchy to define a new index namely traffic incident management ratio (TIMR). The TIMR is defined as the ratio between the expected total travel cost of the degradable transport network without traffic incident management program (TIMP) and with TIMP. The paper assumes the user equilibrium (UE) to represent the degradable network condition without TIMP whereas the social optimum (SO) is used to characterize the degradable network condition with TIMP. The critical link capacity degradation evaluation model is then proposed based on the maximum value of TIMR. Traffic incident impact factors including traffic disruption and accident severity are also considered in the model. The model can quantify a critical level of link capacity degradation and identify the critical links for appropriate resource allocation for long-term TIMP. The model and algorithm are tested with a hypothetical network to illustrate the application of the model.

抄録全体を表示

Japan has more than 6,000 small islands, and it is often the case that these islands do not have the needed industrial resource. So, tourism business is important for most of these islands. However at present, the decreasing number of tourist is causing problems to the tourism business of the island which is often used for recreation. It is necessary to formulate the measures for the promotion tourist demand. For this, the purpose of this study is to propose the strategies for the promotion of Sado Island, which is used as the case study. In order to objectively propose strategies, analysis of tourist activities and preference was done using the tourist survey data. In this paper; we tried to analyze the transportation mode choice behavior by discrete choice model and visitors preference by factor analysis and discriminant analysis.

抄録全体を表示

The recent literature indicates a growing adoption of Artificial Neural Network (NN) in travel demand modelling, and this study is one of them, focusing on passenger trip distribution, especially work trips. Various models of NN were developed with the variables of learning rates (LR), hidden layer node numbers (HLNN), and percentages of dataset for training, validation and testing. Comparisons with the Doubly Constrained Gravity model (DCGM) were used to measure the performance of NN models. The results suggested that the validated NN model with learning rate 0.1 can almost reach the same performance of DGCM model. Further, the statistical test results shows that the NN models are unable to reach the same performance as DGCM although the NN model was trained, validated and tested using the same data.

抄録全体を表示

Focusing on the household behavior of vehicle holding duration and annual traveling distance, this study attempts to propose a Copula-based Multivariate Survival (CMS) model to capture the interdependence between these two behaviors. The copulas can be applied to the multivariate models to accommodate various correlation structures. This study applies the widely-used copulas in other research fields, including Normal, Gumbel, Clayton, and Frank copulas, and explores how these copulas could fit the data in this study. An empirical analysis is carried out based on web-survey data obtained in the Chugoku region of Japan in 2006. Model estimation results confirm the effectiveness of the suggested CMS model form both model performance and applicability. Comparative analyses of the different types of copulas support the use of Clayton copula, and the relevant CMS estimates that vehicle holding duration and vehicle use are significantly correlated with each other.

抄録全体を表示

This study aims to suggest reasonable method of analyzing automobile users empirical cognition on travel mode choice. This study defines the concept of Automobile User Value(AUV), as, the ratio of transportation service that automobile users acquire to cost that they pay. The analysis frame is developed by considering Customer Value and Service Quality(SERVQUAL) model. AUV is divided into expected value and perceived value, and evaluated by SERVQUAL model. The analysis of AUV indicates that the AUV score is 4.6 times higher in automobile than transit. Path analysis shows that the effectiveness of automobile's motive to transit's motive was low. Various policy alternatives for modal shift have been made to relieve transportation problems. But the auto mode share has increased mainly due to ignorance in policies about AUV. In order to improve transportation systems, it is strongly recommended that AUV should be surveyed and analyzed.

抄録全体を表示

Synthetic baseline population data is one of the most important data required for the activity based travel demand model. The conventional approach to create this baseline population mainly relies on the Iterative Proportional Fitting (IPF) procedure. However, the traditional IPF procedure assumes the known input data from both the observed cell counts and their marginal counts. This paper presents the application of least square procedure for estimating baseline population distribution in the area where only partial marginal distribution data are available. The method concentrates on optimizing the least squares of the errors between the estimated conditional probability and the target conditional probability, given the constraints of underlying population information in the study area (such as total population, total population by gender, and total population by age etc.). Numerical examples and the case study of Phitsanulok city in Thailand are also presented.

抄録全体を表示

Inferring trip origin-destination (O-D) matrix in a vehicular network using partial link flow information is a critical issue for transportation planning and traffic management. However, due to a budgetary constraint, the minimum subset of links to be equipped with vehicle detectors (VDs) and their installation locations need to be determined to provide a desirable O-D matrix estimate. In the present research, a linear algebra-based method was developed to deal with the network location problem. Given a network structure represented by its link-path incidence matrix, some crucial links were strategically identified by a basis link model (Hu et al., 2009a, b) and the collected link flow information were further incorporated into an O-D matrix estimation model based on link flow conservation rule without any unreasonable assumptions, such as known prior O-D information and/or users route choice probability. Numerical results based on a simplified real highway network indicated that the O-D matrix estimates given by the basis link model combining with the proposed O-D estimation model are generally satisfactory.

抄録全体を表示

The purpose of this study is to explore relationships between actual amount of information and communications technology (ICT) use and travel by developing trip generation models considering ICT use variables. The data for this study come from an ICT use and activity diary survey of 269 households (860 individuals) in Seoul Metropolitan Area in 2006. We developed regression models of number of trips by mode considering socio-demographic variables as well as ICT use variables. It turned out that ICT use variables have statistically significant positive effects on travel. Furthermore, assuming that interrelations between ICT and travel exist, structural equation models were developed taking them as endogenous variables. The model results strongly suggest that ICT use positively affects travel indicating complementary effects.

抄録全体を表示

Bus service supply has diminished and finally abolished in an underpopulated region where public transport demand is in an extreme low density. Its mobility is very low as well as restrictive for elderly people and disadvantaged people who have no private means. The paper analyzes travel behavior by car passengers and community buses in a mountainous under-populated region, Yamakoshi in the city of Nagaoka, Niigata in Japan and estimates travel mode choice models using travel diary data to reveal the constraint factors of mobility for elderly people. Finally, the paper clarifies an important factor of walking distance from home to a bus stop to shift travel mode from car passengers into an exclusive club bus system for elderly people.

抄録全体を表示

The shift of travel demand policies, from the conventional supply oriented to the management oriented policies, has made the effectiveness of conventional models questionable. However, the new generation travel demand models have so far failed to fully engage practitioners, despite their appealing backgrounds. The requirements and the complexity of the new generation models have contributed to the wide gap between the research and the practice. This paper suggests a way to incorporate the features of new generation models using ordinary resources (person-trip data), to narrow the gap. We propose a relatively simpler model that takes incremental improvement approach rather than pursuing a swift full-fledged shift, which many of recent innovative new models are characterized with. We also illustrate the practical advantages of the new generation models, comparing with conventional models, in evaluating policies by an empirical case

抄録全体を表示

The first step to study trip distribution is to divide physical space under investigation into mutually exclusive zones or locations. Calibration of the gravity model involves adjusting the friction factor with Newton-Raphson Method. An important consideration in developing the gravity model is "balancing" productions and attractions. Balancing means that the total productions and attractions for a study area are equal. The objective of this paper is to present the pattern of balancing factor in Gravity to achieve convergence with any beta values as input, using Matlab program. It is shown, by way of exponential as friction factor and using Double Constraint Gravity as balancing factor, we could see that the bigger beta value as input, the longer iteration to achieve convergence.

抄録全体を表示

In developing countries, the inclusion of social factors to travel in transportation research has not yet been well explored. The objective of the study is to explore the effects of social factors to travel in the context of university workers in Metro Manila. Social factors include social interaction, social activities and social network. Structural equation model analysis was used to analyze the causal relationship between social factors and travel. The estimation results indicate that there exists a positive and significant effect of social interaction on social network and on social activities. Social interaction also has an indirect positive and significant effect to social activities via social network. Furthermore, social activities portray a strong and significant positive effect on the degree of travel. In general, these findings imply that social factors play an essential role in the study of travel behavior in developing countries.

抄録全体を表示

There are land uses, that are substantial trip attractors during the morning commuting peak hour. However universities are unique in the existence of several additional traffic peaks during the day. A model for student commuter behavior based on parking congestion cost and arrival (departure) time is proposed and validated. The model is theoretically formulated considering the equilibrium conditions and numerically validated using a bidirectional, real dataset collected and classified on the road connecting the Kawauchi and Aobayama Campuses of Tohoku University, Sendai, Japan. This model captures the effect of congestion such as the presented on the parking lots; and also, the effect of the queue in terms of psychological discomfort.

抄録全体を表示

The formulations of the user-optimal dynamic traffic assignment (UODTA)-based network design problem (NDP), signal setting design problem (SSD), and the integrated NDP and SSD problem (NDP-SSD) for the deterministic (DET), stochastic (SP) and robust (RO) optimizations are reviewed. The modifications of the simulated annealing (SA), genetic algorithm (GA) and reactive tabu search (RTS) for the nine problems (DET/SP/RO of NDP/SSD/NDP-SSD) are discussed. In the experiment, SA, GA and RTS are compared for the nine problems to identify best algorithms. The best algorithm for each problem is employed to find a best solution, which is then evaluated under stochastic condition. We find that the RO solutions yield the best robustness and lowest risk, whereas the DET solutions perform worst. The integrated robust approach is the most desirable, and the next best approach is the sequential robust approach. The deterministic approach can yield worse solutions than the do-nothing case.

抄録全体を表示

In the calibration of the mode choice model, the observed disaggregated data, such as the personal survey data, are theoretically more desirable than the aggregated data, such as the zonal based average or total data. Zonal based aggregate data, however, are commonly used to calibrate a mode choice model because of a lack of observed information on the values of the attributes of a specific traveler in the disaggregated data. Especially, there are usually no observed data on the service attributes of unchosen alternative transportation modes for individual passengers in household travel survey data. This study suggested a method of estimating the values of unobserved attributes of alternative transportation modes using the observed statistical distribution of the attribute's values such as the travel time for each transportation mode for each zone pair. The study also showed a sample application of the method in calibrating the mode choice model using household survey data.

抄録全体を表示

The Tsukuba Express line commenced operations in August 2005, connecting Tsukuba city and Tokyo metropolitan, Japan. Based on the Tsukuba Express Railway Project, the transportation system includes road network and local bus network which had greatly restructured Tsukuba City and its surrounding area. The objective of this paper is to understand the impact of Tsukuba Express Railway Project on the actual travel pattern and behavior of the residents of the surrounding areas of Tsukuba Express. The study conducted panel data survey before and after Tsukuba Express operation. Results indicated that residents patterns and modal choices have changed significantly.

抄録全体を表示

This paper proposes a method for sequential updating of the short-run and long-run price elasticities of traffic demand incorporating regional differences based on hierarchical Bayesian approach. The elasticities are treated as uncertain elements and updated to make an adjustment of our expectations/beliefs in the behavioral responses. As an empirical analysis, the updating is demonstrated from January through August in 2008 by using monthly traffic volume data on 54 expressway routes in Japan, which include two notable periods: the outdated temporary tariff rate (during April 2008) and the rapid increase of gasoline price (until August 2008). The results show that, even within a year, the short-run and long-run elasticities are quite unstable across space and over time, and underscore that we should make a continued observation of both short-run and long-run elasticities in order to monitor the change of behavioral responses to gasoline price fluctuations.

抄録全体を表示

Travel behavior changes over time and such changes might be not the same across individuals, either. In the context of stated choices, such behavioral dynamics might become more complicated. This paper proposes a new DGEV (Dynamic Generalized Extreme Value) model with the observed heterogeneity for not only SP data, but also the combined SP/RP data to further improve the predictability of the stated preference (SP) data. The DGEV model is used to simultaneously capture initial conditions, state dependence, and future expectation as well as time-varying tastes. Heterogeneity is measured with respect to the observed individual tastes to levels of travel services. An empirical analysis is conducted using a 4-wave panel data of travel mode choice collected in Hiroshima City in 1987, 1990, 1993 and 1994, where a new transit system was targeted. It is confirmed that the proposed models are effective to capture heterogeneous dynamic in travel mode choice behavior.

抄録全体を表示

The sources of errors in travel demand model output are not only from a lack of information related to the parameters that the model tries to estimate but also due to the absence of sharply defined criteria of class membership that can play important roles in human thinking, for which qualitative variables may be better representations. Fuzzy Set Theory (FST) is suggested as an approach to tackle the computation of such variables. Combined with other approaches, in this case Artificial Neural Network (NN) and Doubly Constrained Gravity (DCG), the FST is used to model intra city work trip distribution with trip length addressed as a fuzzy attribute. However, the fuzzy model tends to perform with the same level of accuracy as un-combined models. In some cases, the hybrid models have a slightly lower performance than NN and DCG. Findings from this study suggest that FST may be suitable for inter city trip, but not short trip distribution model.

抄録全体を表示

Influence area means the spatial range that the change of traffic flow pattern is remarkable after the construction of highway facilities. The influence area would be a significant criterion for economic analysis because it has an effect on the benefit estimation. However existing methods for establishing influence area (such as the O/D method, the method using variation of traffic volume and the method using variation rate of traffic volume) have no standard criteria. In this paper, problems which existing methods have are analyzed and a new method using select link analysis is proposed. Influence area could be established as the set of zones having 70 percentile cumulative trips out of OD pairs using selected link. In addition, the value of standard criteria for establishing influence area is suggested and it is validated via case study.

抄録全体を表示

This paper presents an empirical analysis of weekday and weekend joint travel tours, made by two or more members of the same household, especially focusing on weekday travel data and comparing the results of a large-scale household travel survey and an activity diary survey conducted in Jakarta, Indonesia. Comparison of weekday travel data from the two surveys suggests that the number of persons per joint tour as well as the joint tour ratio itself is larger in the activity diary dataset. In addition, unlike observations in developed countries, Jakarta dataset has a considerable number of joint tours of which activities are categorized as mandatory (work/school). Moreover, international comparison between the US and Jakarta cases revealed some distinguishable characteristics mainly caused by differences in mode shares and household characteristics. The result of this study was one of the important bases for developing a comprehensive activity-based travel demand model for Jakarta.

抄録全体を表示

The gravity model is the representative approach of trip distribution drawn between the spatial interaction of trip making and travel costs. However, the standard gravity model shows the modeling limitation due to distance-based distribution in cases of polycentric city structure. Many transportation researchers insist that the gravity model should be improved by concerning new variables of areal characteristics or interzonal relative attractiveness. This research develops an estimation procedure for interzonal relative attractiveness as a new variable for explaining zonal spatial properties and interzonal spatial association using 1996 and 2002 interzonal commuting trips of the SM city. The research is extended to develop an improved trip distribution model containing the counterpropagation neural network with three hidden layers. The applicability of the improved model is evaluated by four criteria.

抄録全体を表示

The main purpose of this paper is to evaluate the future trip generation in the Jurong Lake district using GIS based modeling. To facilitate, data collection method was conducted by using geospatial data which obtained from the Singapore Raster Image Data of Singapore Land Authority. With detail zoning, therefore the zones within study area are classified by the land use category (residential, commercial, industrial, recreational and institutional). The Gross Floor Area (GFA) of each building in the zones boundary is measured by computing of plot area ratio or building heights with ground floor area with more extensive use of ArcGIS 9.2 Software. Then the proposed of trip production and attraction was derived by multiplying Gross Floor Area (GFA) and ITE Trip Generation Handbook for respective buildings and land uses with assuming that the trip generation rates for conditions found in the United States is applicable. This paper also discussed some recommendations and measures to improve trip generation rates by using geospatial data.

抄録全体を表示

The activity duration study in activity-based approach typically has analyzed by the regression models that manifest the relationship between socio-economic variables for independent variables and activity duration for dependent variable. Among various approach, the most frequently adopted model is the hazard-based model, which is a parametric model because it assumes the probability distribution of the dependent variable prior to model estimation. Especially, when the true distribution has a unique pattern, we have difficulty in choosing the relevant probability distribution functions. This study aims to develop the activity duration models using kernel density estimator. KDE is a type of nonparametric estimation methods and can construct the probability distribution including some special features, which parametric methods hardly describe. In addition, relationships between travel time and activity duration are also investigated using the bivariate KDE using travel diary survey data.

抄録全体を表示

The development of integrated transport supply and demand management (TS-DM) strategies is crucial for ensuring sustainable urban development. Any TS-DM strategy will not only affect the transport system performance, but also result in changes of the land use pattern. Moreover, implementing TS-DM strategies normally involves a progressively phased long-term schedule; one must take into account the total accruing costs and effects over time so as to optimize the system performance. This paper develops a mathematic optimization program with equilibrium constraints (MPEC) to study the impact of TS-DM strategies on transport system performance and activity location costs expressed as land value. Specifically, a bid-rent mechanism via the random utility approach is developed to model residential location choices. Finally, a numerical example is provided to compare among different strategies. Through this study, we hope to introduce promising planning perspectives to create win-win scenarios for both users and transport system managers.

抄録全体を表示

ThThis paper examines the characteristics of the choice behavior of urban rail users in the Tokyo Metropolitan Area and proposes heuristic rules for generating an individual's choice set by eliminating the options by his/her aspects. Then, this paper empirically applies the proposed rules to the simultaneous choice analysis of the access travel mode, rail station of origin, and rail route using multinomial logit models. The results show that the choice set generation rule with two-step elimination according to the access distance to the rail station of origin and the total travel time, including access travel time and rail-ride travel time, exhibits the best fitness in the parameter estimation.

抄録全体を表示

This paper attempts to propose departure time choice model of travelers for going to city centre based on disutility that derived from three processes of going to a place for an activity. The first is leaving home process: process from leaving home or origin to arrival at the place or destination in city centre. The second is staying at the activity place: process from arrival at the destination to the leaving the place to return home. The third is returning home: process from leaving destination to arrival at home. The model was applied to the people who went to a city centre for daily shopping. By a goodness of fit test, it was revealed the proposed model was acceptable. The model is to be applied to develop a mode choice model in further studies.

抄録全体を表示

Existing studies have shown that decision of activity participation and time allocation behaviors are interdependent. This study reconfirms this finding using a Japanese national time use data collected in 2001 by developing a joint discrete-continuous time allocation model to represent the interactions between activity participation and time use behaviors over the course of a day. A binary logit model is adopted to describe activity participation behavior, while a utility-maximizing time allocation model is established to calculate the time allocated to each activity. The estimation results show that personal attributes, household attributes, and external environment attributes have a significant impact on activity decision. The negative parameter for the above interaction suggests that competition of time allocation occurs across activities. Furthermore, it is also confirmed that individuals try to allocate available time on different activities equally in order to increase his/her utility.

抄録全体を表示

Illegal parking is one of the factors to cause traffic congestion and traffic accidents. Therefore, it causes tremendous social cost such as time-loss due to the traffic congestion and loss of human recourses due to traffic accidents. In Japan, to decrease the occurrence of illegal parking, Road Traffic Law (RTL) was amended in June, 2006. The main purpose of the amendment is that to check illegally parked vehicles and put parking tickets on the vehicles are consigned to private sectors. The National Police Agency of Japan reported that the number of illegally parked vehicles has been decreasing, and that the use of the parking lot has been increasing. In order to continue these effects, we have to investigate the change in driver's consciousness before and after the amendment of RTL. Then, this research estimated parking place choice model using SP survey data, and clarified that the driver's consciousness had changed.

抄録全体を表示

West Java Province has great potential in produce vegetables, fresh fish, fruits, cutting flowers etc as commodities for air cargo, even though until now only 1,29% has exported. By LQ analysis and simple regression can be forecast for year 2013 for 10% production scenario to export, it need support by 788 aircraft movement (2 aircraft/day) of Boeing 747-400 air cargo carrier and 10.910 (30 aircraft/day) of Boeing 737-700 air cargo carrier, and this demand trend to increase. Base on the air cargo demand consideration, the limmited development of Husen Sastranegara airport and the barrier access to Soekarno-Hatta airport, so the special airport for cargo has to build as soon in order as export gate of West Java and Indonesia.

抄録全体を表示

Simultaneously owning different types of vehicle including car, motorcycle and bicycle is addressed in this study by using ramdom utility models. The empirical analysis uses large scale person trip survey data for the two biggest Metropolitans in Vietnam and adopts multinomial logit (MNL) models and nested logit (NL) models as approaches to describe vehicle ownership at household level. The results indicate that income is a dorminant factor for vehicle ownership of any type and its effects are larger on car and motorcycle ownership than on bicycle ownership. Motorcycle is used as a substitute for bicycle in Hochiminh metropolitan (HCM) while the reverse thing holds true for Hanoi area.

抄録全体を表示

Wide range of transport policies and public transport systems has to be necessarily evaluated before implementation to assess the benefits and impacts on travel demands. In order to achieve this it is very important to analyze trip maker behaviour especially in choosing mode as it plays pivotal role in estimation of trips based on mode. In this paper, an attempt was made to model the choice behavior of commuters presently using public transport in the city of Ludhiana, India based on Logit and Fuzzy Logic techniques. The choice data was collected through commuter interview survey and results from the developed models are encouraging and show good statistical validity. The study highlighted merits and demerits of each of these choice models. Through this study, the superiority of an intelligent technique like fuzzy logic in developing mode choice model over logit model was demonstrated.

抄録全体を表示

When transport systems get overloaded due to escalation in travel demand, it becomes poor in quality as well as quantity of service. Therefore the existing transport system needs to be expanded with introduction of new modes of mass transportation. This can be done by studying the travel behavior and choices of commuters, which is known as mode choice modeling. In this paper the mode choice behavior of the commuters having a personalized mode for different journeys in the second order metropolitan cities of India (population range of 1-2.5 millions) was modeled. The mode choice models based on Logit and Artificial Neural Networks (ANN) for work, education and others trips are validated and compared. The choice behavior data for this exercise was collected in the cities of Visakhapatnam and Nagpur. Further, the results have shown that commuters are placing more weight on travel time than travel cost.

抄録全体を表示

During the ongoing development of transport models in Thailand, the regional city of Phitsanulok was chosen as the first case for the development of an Activity Based Transport Model for the Kingdom. The city is situated in the Nan Basin, which is part of the Chao Phraya Watershed and is some 377 km north of the Thailand capital, Bangkok. This new model will include a full activity based model incorporating a population synthesizer. The heart of the model is the Geodatabase. This model includes many of the recent development tools in Land Use Modeling and Dynamic Assignment Procedures. An enhancement of this model can link the strategic model to Micro Simulation/Animation. By design, it is multimodal model in nature incorporating person movement modes of car, bus and walk whilst for cargo transport it incorporates the modes of road, rail and inland water transport.

抄録全体を表示

Walking is human's fundamental means of transport, and primary means to connect between transportations. Even though there are increased studies on pedestrians and the requirement for pedestrian demand analysis, there are few studies on pedestrian assignment. The object of this study is to develop pedestrian assignment algorithm applicable to a mega-building and general sidewalk, and investigate the applicable possibility. This paper consists of literature reviews regarding vehicle and pedestrian assignment, methodology on pedestrian assignment, experiment and analysis, conclusion and future study.

抄録全体を表示

Special traffic measures refer to traffic solutions implemented in order to effectively respond to national traffic management due to rapid increases in transportation demand during special periods such as the Seol or Chuseok holidays. The need has developed for modifications in training to faithfully enact the special traffic measures contents and reflect changes caused by the traffic system efficiency law amendment. To analyze the summer vacation special traffic measures period, transit records for the relevant period will be collected and organized into daily average transit records, and the basis of a daily fluctuation factor will be used to examine concentration levels of transportation demand, thereby analyzing the appropriateness of the measures period. According to comprehensive analysis, it appears that the summer vacation special traffic solution period should be designated from July 25th through August 10th. This is about 10 days shorter than the original solution period.

抄録全体を表示

This paper firstly analyzes the structure of the existing container shipping network, which covers several areas located respectively in two counties, and develops a new kind of shipping network that consists of trunk and feeder lines. Secondly, the paper constructs a bi-level programming model that can be used to optimize the container shipping network with the aim to minimize the generalized transport costs. Then the model is tested with container O-D data between the ports in the Surrounding Bohai area in China and two ports in the West of the USA. Through the test calculation, a feasible optimized shipping network consisting of trunk and feeder lines is founded for the case study area.

抄録全体を表示

This paper explains the analysis to calculate road pavement distress loss cost resulted from overloading and therefore the amount of loss cost the overload car users shall bear can be determined. Overloading heavy vehicle causes road pavement structural distress and service lifetime decreasing during design lifetime. The presence of overloading is indicated by the width area of rutting which is more than 60% of total road structural distress per km and by real maximum axle load (MAL) of the heavy vehicle which is larger than its standard MAL. The loss cost of road pavement distress due to overloading is calculated based on damage factor (DF) and deficit design life (DDL). The loss cost the overload car user shall bear is 60% of total DFC (damage factor cost) and DDLC (deficit design life cost), considering that not all pavement structural distresses are absolutely caused by overloading freight transport.

抄録全体を表示

Efficient sea transportation is heavily dependent on the smooth operation of modal interchange, meaning that intermodal transfer is a key element in successful shipping operations with massive transshipment in major seaports. This paper discusses the development strategies of container ports towards the intermodal freight transport systems, examining real world decision problems. Having obtained a good understanding of the data acquired, shippers' perceptions of container transportation and port service were analyzed. The cross tabulations together with the statistical techniques of factor analysis and ANOVA analysis were applied in order to analyze data comparisons and the relationship between the service purchase behavior and the degree of satisfaction for development strategies.

抄録全体を表示

The freight shipping industry has become an important part of logistics services. Many companies view business customers as major sources of revenue. Under fierce market competition, managers of freight shipping company must find ways to maintain customers through continuous cooperation and enhance customer loyalty and satisfaction. This study explores the effects of service quality and relational performance on customer satisfaction and loyalty in a business-to-business context. This study adopted business customers of freight shipping companies in Taiwan as its sample and collected data via a self-administered questionnaire. After applying structural equation modeling to test the theoretical model, analytical results show that customer loyalty was influenced by the level of satisfaction. Additionally, the relational performance and service quality significantly affected satisfaction. Finally, this study discusses managerial implications and offers suggestions for future research.

抄録全体を表示

This paper outlines a research on the analytical model of multi-mode multi-commodity freight transportation in Indonesia. The model is intended to evaluate strategic plan of inter island freight transportation. The demand for inter island freight transportation is estimated by econometric demand models taking into account socio-economic characteristics of the regions and types of commodities. Supply side concerns with the network, including land access connecting to transfer points, especially with respects to modeling links, transfer points, and generalized cost function. System optimization is obtained by minimizing total cost consisting of link and transfer cost. The model is applied to evaluate impacts of policy scenarios contributing to improvement of inter island freight transportation network and has shown its capability of estimating system costs that can be utilized to assess policy implications.

抄録全体を表示

This paper discusses the theoretical framework for considering network design and choice of aircraft size in order to understand the hub dominance in the air cargo transport markets. The model is a bi-level market model that is constructed by freight carriers' behavior as leader, and shippers' behavior as follower. We assume the duopoly market in which freight carriers aim to maximize their profit by designing shipping network. Shippers aim to reduce their generalized shipping cost which consists of shipping time, waiting time, tariff and congestion. We assume that the equilibrium flow of commodities is given as stochastic user equilibrium flow. Computation results suggest that the carrier which holds the dominant hub airport rules the market but the hub dominance is unstable. Hub dominance heavily depends on the balance between runway capacity and local cargo flows.

抄録全体を表示

The vehicle routing problem (VRP) is an important problem in the field of logistics management. As an NP-hard problem, the VRP real world sized instances cannot be solved to optimality within reasonable times. This research aims to develop a two-stage ant colony optimization (TACO) algorithm, which possesses a two-stage solution construction rule, to solve the large scale vehicle routing problem (LSVRP). In the first stage of the solution construction rule, the VRP is decomposed into several sub-problems (traveling salesman problem). Then each sub-problem is solved by an improved ant colony system (ACS) in the second stage of the construction rule. The performance of TACO is tested by 14 VRP and 20 LSVRP benchmark instances and compared with other meta-heuristic approaches in the literature. The computational results show that our TACO can obtain good solutions for large scale VRP instances and its performance is competitive with other well-known meta-heuristic algorithms.

抄録全体を表示

This study examines the determinants of location decisions on domestic shippers. To do this, this study identifies with the aid of the location choice model. We have used Korea commodity flow survey collected by the inter-regional shippers and socio-economical indicators. The results suggest that the location of shippers depend on agglomeration economies, market size, as well as logistics activities. The influential factors of location choice are as follows. Firstly, the influence of transportation time should be accounted for. The suggested models show a large volume of transportation for a short transportation time and a small volume for a long transportation time

抄録全体を表示

Unlike widely available literatures in hazardous material (HAZMAT) transportation that basically aim at finding non dominated paths for a given origin-destination pair, our main focus in this study is on vehicle routing problem with time window (VRPTW) aspect of HAZMAT transportation problem that has received very less attention in literatures. We present a new multi-objective optimization model and its meta-heuristic solution technique using Ant Colony System for HAZMAT routing. In contrast to existing local routing models, we consider minimization of risk and transportation cost in both route choice and routing phases of transportation process. Moreover, route choice and routing have been carried out as a single step process. Lastly, the proposed algorithm has been tested for normal VRPTW by testing on Solomon benchmark instances and the results obtained show that the proposed algorithm outperforms while maintaining realistic computation time.

抄録全体を表示

This research attempted empirical analysis of trucking industry in Korea through the estimation of cost function, and for the empirical analysis the data were established based on new method. In the establishment of data which was the constraint of research, analysis was performed using the estimated data instead of using the existing surveyed data. In the comparison of analysis results, this study case and other cost function analysis was compared with the economy of scale, the sign and sequence of elasticity and the result showed similarity between them while showing accord with other researches in considerable portion

抄録全体を表示

This research discusses on study undertaken for improving the distribution chains of export-import commodities in Jakarta. Two possibilities stand for such capacity improvement are to develop other port at different point or to develop dry-port away but closer to industrial estate as focal point.

抄録全体を表示

Hub facilities serve as transshipment and switching points in transportation and telecommunication networks. This paper deals with the uncapacitated single allocation p-hub median problem (USApHMP), which is a well known NP-hard problem. Few studies applied simulated annealing (SA), tabu search (TS), and genetic algorithm (GA) to solve the problem in the past decades. A threshold accepting (TA) algorithm is proposed for solving the USApHMP. The numerical experiments were carried out on two sets of benchmark instances, CAB and AP, from the literature. The results show that our TA algorithm is efficient and competitive with other approaches. TA can obtain all the optimal solutions in the CAB data set and update two best-known solutions of large instances in the AP data set.

抄録全体を表示

The Air Force temporarily stores its domestic and imported military supplies in one central depot after purchasing them from many suppliers. Then it tries to efficiently distribute the needed supplies from its central depot to air bases. In addition to such strategy, the Air Force also has an optional strategy of minimizing damages at its central depot due to enemy attacks. This optional strategy provides for two extra depots as supplementary distribution centers to maintain a proper supply system even in such emergency situations. During normal periods, such role is insignificant, however, from the perspective of the entire supply system. The manner of better utilizing these supplementary depots is still under consideration and in the development stage. This study focused on utilizing these two supplementary distribution centers to devise a more flexible supply distribution system for the Air Force and optimally assign air cargos and their paths so as to minimize the total distance.

抄録全体を表示