Journal of Transportation Systems Engineering and Information Technology

Energy Conservation and Emission Reduction of Integrated Transportation System

ZHANG Guo-wu

2010, 10(2): 2-11 .

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The 18th Conference of “Traffic and Transportation Forum 7+1” sets its theme as “energy conservation and emission reduction of integrated transportation system”. With the rapid development of economy, the contradiction between increasing transport capacity and limited energy resource appears to be more serious than ever. The energy consumption and emission is directly identified in the process of service production. While, its amount have strong relationship with the overall planning, layout, equipment, and structure of the integrated transportation system, instead of merely determined by the production process. The differences of the domestic and international statistical caliber are analyzed, and the energy consumption level in China is estimated with the international caliber. The results indicate that the transportation consumption level is underestimated in Chinese transport industry, especially the level of petroleum. The consumption factors of different transport mode are presented then. Moreover, the coming challenge, future direction, and relevant count measures are discussed for energy conservation and emission reduction of integrated transportation system.

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On Urban Rail Transit Development of China

WANG Qing-yun

2010, 10(2): 12-16 .

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With the recent development of Chinese cities and experiences from abroad megacities, the paper addresses the necessities and principles of urban rail transit development in China. Several major relationships are analyzed in terms of railway and urban traffic, public and non-public transport, as well as rail transit and bus. Thus, the potential advantages and future directions are illustrated for establishing the rail-oriented public transit system. The developing principles are proposed, which suggests a rail network suitable for the overall planning of one city. The appropriate mode and economic and structural factors should also be considered for rail transit development, and the over-advanced construction should be avoided. In the final section, the detailed measurements for developing rail transit are presented with illustration on the fund raising approach.

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Trend Analysis of 2009 Integrated Transport Systems of China

MAO Bao-hua,PENG Hong-qin,JIA Shun-ping

2010, 10(2): 17-22 .

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With the statistics of transport system development in 2009, the paper analyzes the impacts of global financial crisis on infrastructural construction. By comparing with several typical countries on their traffic volumes, economic data and also populations, the authors demonstrate the relationships among transportation and social economic indicators, and further advance a definition of the stages of transport and economic development process. It also points out that there is still big space for the construction of transport infrastructure in developing country as China. Considering the differences on regional characteristics in developmental environment, the authors systematically compare several indicators on transport and economic of six typical Provinces located in different parts of China. Based on the technical and economic characteristics of different transport modes, it gives four suggestions on how to work out the integrated transport plan under the socialist country such as China.

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Multilevel and Multimodal Comprehensive Transport Network Design

ZENG Ming-hua,LI Xia-miao

2010, 10(2): 23-29 .

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The paper investigates the sustainable network design for multilevel and multimode transport system. The hierarchical factor is defined by transport hierarchy, and the generalized path cost is formulated with traffic negative externalities involved. Nonlinear programming is then established for Logit-stochastic equilibrium model of multilevel and multimode comprehensive transport network. An algorithm for multilevel multimode transport network is proposed accordingly, and the numerical experiments of selected network are conducted. Hierarchy elasticity and demand elasticity of network total generalized cost are defined and focused on. The study also analyzes the impact of mode split parameter on the total generalized cost of networks with different hierarchical structure and demand elasticity of average generalized cost with different mode split parameter value. Results show that the designed comprehensive transport network with transport hierarchy is well adapted to the growth of traffic demands without network great performance deterioration and that hierarchical transport network is insensitive to the change of mode split parameter value.

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Policy Implications of Incorporating Hybrid Vehicles into High-Occupancy Vehicle Lanes

K S Nesamani,Lianyu Chu, Will Recker

2010, 10(2): 30-41 .

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High-occupancy vehicle (HOV) lanes have been regarded as a cost-effective and environmental friendly option to help move people along congested routes. In spite of wide adaptation of policies, the effectiveness of HOV systems has been criticized for its under-utilization. A California statewide policy that allows hybrid vehicles to use HOV lanes was adopted under the expectation that vehicular emissions would be reduced by encouraging drivers to use fuel efficient vehicles as well traffic congestion would be eased through the more efficient use of the reserved capacity on the HOV lanes. To test the validity of this expectation, the impacts of the policy on the freeway network in Orange County, California was investigated using a method that combines a traditional planning model for demand estimation and analysis with a calibrated microscopic simulation model for accurate measures of system performance. The policy was analyzed in terms of overall system performance, corridor level performance and air quality. The key findings from this study are that the policy can be expected to have significant negative impact on HOV lanes that do not have reserve capacity. The maximum number of hybrid vehicles that the Orange County HOV system can absorb without significant degradation is about 50,000, and within this limitation, the policy can be expected to be successful in reducing emissions by allowing hybrid vehicles into HOV lanes.

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A Ontology-based Semantic Fusion Model in Information Integration of Urban Transport

YANG Wang-dong, WU Hong-bin,HUANG Xue-hua, LI Chang-yun

2010, 10(2): 42-48 .

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Traffic information fusion technology receives increasing attention in intelligent transportation system study. It is rather important for the integrated management of urban transportation, traffic and emergency response plans, and the construction of digital cities. The fusion and unified representation of heterogeneous multi-source are deeply analyzed using ontology technology and methods of logic algebra semantics. To achieve the fusion of urban traffic information in the semantic completeness and consistency, it develops a semantic model of static and dynamic information through urban transportation ontology and defines the statute and the algebraic operations of semantic fusion in ontology level. With newly-added semantic fusion function, the method is capable of reducing the data amount and improving the efficiency and accuracy of the integration of traffic information query and analysis.

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BP Simulation Model and Sensitivity Analysis of Right-turn Vehicles’ Crossing Decisions at Signalized Intersection

LI Shan-shan,QIAN Da-lin,LI Nian-yuan

2010, 10(2): 49-56 .

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Inter-crossing behavior model of motor vehicles and bicycles is the key part of micro-simulation for mixed traffic at signalized intersection. The microscopic behaviors of the motor vehicles passing through the bicycle flow at a two phased signalized intersection were analyzed to reproduce the passing behavior of motor vehicles. A BP neural network model was proposed to describe the motor vehicles’ passing decision. Based on the field data at two typical intersections in Beijing, the model was validated and compared with the Logistic model. The results indicated that the BP model was more effective than the Logistic model and had high prediction accuracy. First derivative sensitivity matrix of the BP model was established. The sensitivity analysis showed that the most important factor impacting on the motor vehicles’ passing decision-making behavior is the gap allowing motor vehicles to pass through. The passing decision-making behavior is the most sensitive to the gap when it lies between 2.76 s and 2.96 s.

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ETC Data Based Traffic Information Mining Techniques

WENG Jian-cheng,LIU Li-li, DU Bo

2010, 10(2): 57-63 .

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The electronic toll collection (ETC) system is an importation subsystem in the intelligent transportation system (ITS). It can continuously record the time of vehicles entering or departuring from the certain toll station. Based on the charge transaction data of ETC system, this paper analyzed the original data and determined the data processing flow of ETC Data. Then, it proposed the travel speed calculation model of freeway, the traffic flow distribution analysis method, the information mining techniques of OD distribution, vehicle type proportion in different toll gate, and so on. The research finally took the ETC data of Beijing city in 2008 as an example, and carried a case analysis. The result indicated that the data processing and the index extraction techniques can accurately gain the information which is necessary in the freeway operation and management. These provide effective decision-making support for the freeway travelers’ information service and the highway traffic operation and the plan.

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Switch Curve Information Based Train Positioning Method

WANG Jian, LIU Jiang,SHANGGUAN Wei,CAI Bai-gen

2010, 10(2): 64-69 .

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The real-time positioning of train is an important part of modern safety-critical train control system. In traditional train positioning method using odometer, only mileage information can be provided, thus it is difficult to solve the problem of track occupied identification in station with several parallel tracks. According to the characteristic of train operation, the switch curve information based train positioning method is proposed in this paper, in which GPS receiver and inertial sensors are employed to obtain train’s operation state in switch, such as the train’s velocity, accelerator, and angular rate. The study calculates the difference of turning radius and rate of curvature and finds the running direction. Then the track occupied identification is realized accurately with the comparison to on-board track map database. It also analyzes the way of obtaining train’s operation state and the flow of the matching with curve information. Experimental results demonstrate that, under current conditions, the proposed method earns high ability for track occupied identification and could improve the positioning performance to some extent.

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Intelligent Vehicle’s Path Tracking Based on Fuzzy Control

XIONG Bo,QU Shi-ru

2010, 10(2): 70-75 .

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Autopilot vehicle is an important part of intelligent transportation systems. The objective is to develop the driver assistance systems on highway and urban road, to help or even to replace the driver, which may reduce traffic accidents and improve the efficiency of traffic system. A method based on machine vision and fuzzy control is proposed to realize intelligent vehicles’ autopilot. It uses the CMOS sensor as its path recognition device to draw its lane centerline through image analysis. Taking the feedback speed as the additional input, the study forms the closed-loop control and establishes one graduation fuzzy controller which controls vehicle direction with two fuzzy controller combinations and replaces traditional PID control vehicle speed by fuzzy control. Compare with the conventional PID algorithm and the fuzzy control algorithm, the improved fuzzy control algorithm ensures a high speed and steady running of intelligent vehicle with smaller over modulation in corner.

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Domestic Flight Schedule Simulation Using ServiceModel

HUANG Zi-jun,XU Li

2010, 10(2): 76-82 .

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Flight schedule simulation is an effective, low-cost, accurate, and dynamic estimating method. With the increasing transport volume and airlines of domestic air transport, a feasible and economical flight schedule is rather important. Based on the ServiceModel simulation software, this paper proposes a simulation model operated on airline network for domestic flight schedule. Through the imitation of aircraft turnarounding on airports and flying along airways (among 150 domestic airports), flight schedule simulation model collects various statistics, such as delay time, buffer time, block time, and aircraft usablity. The model not only evaluates the performance of a given flight schedule but measures the recovery results by generating stochastic flight delays for schedule recovery mechanism to handle disruptions.

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OD Matrix Estimation for Urban Expressway

WANG Yuan-qing,YANG Liu, GENG Yin, ZHENG Meng-meng

2010, 10(2): 83-87 .

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OD information of urban expressway is the basis of analyzing the traffic operation and performance. A proper OD estimation method is capable of reducing the traffic surveys pressure and avoid traffic jams during survey and unreal OD information. This paper proposed a systematic method of OD estimation including traffic zone division in the form of the entrance and exit ramps of one direction on expressway, and established the seed OD matrix of high quality using the Gravity and Frator method. It estimated the OD matrix in the OD estimation module in TransCAD software, which was applied in the Inner Ring Road in Guangzhou city. The results showed that the relative errors of the traffic volumes on the links and ramps, the average trip distance and the traffic mileage are small with the seed OD matrix calculation and OD matrix estimation, which manifests that the estimated OD matrix is accurate and reliable and the proposed method is appropriate for the urban expressway traffic analysis.

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On Forecasting of Residents Transit OD

ZHAO Shu-zhi,ZHU Yong-gang, ZHAO Bei

2010, 10(2): 88-92 .

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This paper introduces a method for traffic friction and transit trips forecasting between traffic zones to improve the accuracy of traditional 4-phase method. The traffic friction is defined by the shortest distance between the road’s nodes in each traffic zone. The method avoids the defects of traditional method for the traffic friction. Introducing the traffic friction into gravity model on trip distribution, the forecasting accuracy is improved. Based on the characteristics of present urban residents trip, total quantity of resident transit trips can be forecasted with the Markov chain method, and the residents transit trip proportion between every traffic zone can be forecasted with diversion curve of transit trip distance. The transit OD can be obtained on the basis of the total quantity of residents transit trips and transit trip proportion. The proposed quantitative method is more reasonable because the impact of the city’s landscaping planning and policy are taken into account.

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Optimization Study on Road Pricing with Variable Bus Frequency

YAO Jia-lin, HOU Chao-feng,YANG Zhao-xia, FU Cheng

2010, 10(2): 93-99 .

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The paper proposes the optimization problem of road pricing with variable bus frequency on the basis of the relations analysis of mutual constraints between road pricing and increasing bus frequency considering the interaction of different travel modes. A bi-level programming model is developed by estimating the generalized travel cost of bus and private car traveling. The upper objective of the model maximizes total consuming surplus of network, while the lower is the user equilibrium model with elastic demand of combined mode. The optimal algorithm is also designed based on the simulated annealing algorithm. A numerical example illustrates that the model and algorithm can effectively solve the problem of road congestion.

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Short-term Choice of Travelers with Effect of Traffic Information

WU Wen-jing, JUAN Zhi-cai, LUO Qing-yu

2010, 10(2): 100-105 .

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The travel information system strengths the relationship between travel and transportation system, which makes the activity-travel decision as a dynamic adjust process. After analyzing the travel demand change with the effect of information, the paper focuses on the short term choice of travelers. Based on the SP survey data of Jilin city, it discusses the interaction among depart time, travel mode, and route choice decision behavior. Considering the influence factors such as the of travelers attitudes, the study quantitatively analyzes the inner relationship of route choice behavior using Bivariate Probit model. The results show that the travel mode choice strongly influence the departure time or route choice, and the route choice is independent relatively. These fundamental works provide some knowledge to further process in the research of the traveler’s behavior and provide some valuable advises to transportation programming and management.

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Forecasting Short-time Traffic Flow for Beijing 2nd Ring Road Using Chaos Theory

GUO Min,LAN Jin-hui, XIAO Xiang,LU Hai-feng

2010, 10(2): 106-111 .

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With the ever-increasing motor vehicle population, traffic congestion is a severe problem of urban traffic. Traffic flow forecasting may help the traffic management branch to formulate relevant policies, optimize traffic management and solve the traffic problem, at last release the traffic pressure in a certain extent. It is one of the important issues of intelligent transportation systems. Short-time traffic flow forecasting is the main technology of traffic control and vehicle-based navigation. This paper points out that transportation system is a dissipative system and the chaos exists in traffic status. It restores dynamical systems with chaos and fractal theory and predicts the traffic flow using multivariate time series of local prediction method. The basic traffic data are collected to test the effectiveness of the model, and the evaluation index of different time interval of the traffic flow series is analyzed. The proposed method has high prediction accuracy within 2 or 5 minutes level.

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Traffic State Forecasting Towards Urban Freeway Based on the Maximum Entropy Model

DONG Hong-hui, JIA Li-min,SUN Xiao-liang, LI Chen-xi,QIN Yong, GUO Min

2010, 10(2): 112-116 .

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The traffic state forecasting is an important basis for the traffic-induced system and traffic information dissemination system. The paper proposes a new forecasting method based on the maximum entropy model towards the urban freeway. The maximum entropy model can get the weights for the different features by the data training, and predict the road traffic state level directly. This method can fuse the temporal and spatial features efficiently, regardless of the relativity between the different features, which make this model more adaptable. The experiment results show that this traffic state prediction method can achieve a high accuracy. The success of this model prove that the traffic state prediction problem can be resolved through the pattern classification method, which enhances the methods of traffic state forecasting.

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Relation Analysis for Road Traffic Flow Short-term Forecasting

YAO Zhi-sheng, XIONG Zhi-hua,SHAOChun-fu

2010, 10(2): 117-121 .

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The relation of traffic state data and detective devices exists objectively, but previous attempts to perform short-time forecast are lack of quantitative analysis. Multidimensional scaling from theory of multivariate statistical analysis is proposed to describe the relation for road traffic flow short-term forecast in this paper. It was used to associate the relevance of traffic flows data from road cross-sections with a two dimensional chart of derived stimulus configuration. According to the chart, the strong or weak of the relativity of each road cross-section can be obtained, which supplied research range, object, and base of data analysis to short-term traffic flow forecasting models and methods with consideration of the variety of time and space of traffic flow. The proposed method is verified to be reasonable and effective.

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Road Net Traffic Status Analysis under Traffic Accident Based on Improved BML Model

LIU Xiao-ming, LI Ying-hong, CHEN Yu-mian, ZHENG Shu-hui, LI Zheng-xi

2010, 10(2): 122-129 .

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With the defects of the Biham-Middleton-Levine (BML) model when analyzing the effect from traffic accident in the road network, an improved BML model is proposed. In which, the car driving behavior of changing direction under traffic accident is considered. With this, the car driving rule is more analogous to the actual car action. On the basis of the improved model, the effect of accident amount to average speed is analyzed when the density of traffic flow is given. Then, the effect of traffic flow density to average speed is analyzed when the amount of accident is determined. Furthermore, the effect of the turn probability of car before accident to average speed is estimated. Finally, the relationship between the turn probability distribution function and the average speed of traffic flow is investigated, and some conclusions are drawn with simulation.

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Algorithm and Implementation of Urban Rail Transit Network Based on Joint Operation

HUANG Rong,JIANG Yu-kun, LIU Zhi-li, YANG Yuan-zhou,JIANG Wen

2010, 10(2): 130-135 .

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Fare clearing of lines is a precondition for operating urban rail transit network. According to tickets information from automatic fare collection, an algorithm processes was designed to confirm the revenues that the companies has received from rail transit network, thus improved the operability of fare clearing. Based on the existing fare clearing algorithm under transfer conditions in urban rail transit network, this paper analyzed kinds of organization of urban railway joint operation and their payment, so as to clarify the accounting entities to propose the fare clearing algorithm under joint operation based on multi-path choice. By assuming a network example of three lines with two intervals and calculating its fare clearing, the effectiveness of the algorithm was proved.

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Forecasting Rail Transit Split with Disaggregated MNL Model

HE Ming,GUO Xiu-cheng, RAN Jiang-yu, WU Cai-rui,ZHU Wei, LIU Chao-ping

2010, 10(2): 136-142 .

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The paper focuses on the urban rail transit mode division, and studies the rail transit split forecasting by two stages. At the first stage, the transfer curve method is used to forecast the traffic composition without rail transit. At the second stage, selecting the time and cost as the characteristic variables of the utility function, the study estimates the diverting ratio from all traffic modes to rail and develops the disaggregate model based on revealed preference data and stated preference data survey. In the final section, the paper takes Suzhou city as example to calibrate the model parameters and forecasts rail transit split. The results indicate that the diverting ratio from conventional transit and bike to rail is high. The model improves the accuracy and practicality of the model with consideration of more factors affecting the resident travel mode choice.

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Average Waiting Time Model for Transfer from Rail Transit to Buses

GUO Shu-xia, CHEN Xu-mei, YU Lei,HU Dong-fang

2010, 10(2): 143-147 .

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The modeling of average waiting time for passengers has an important role in several fields of studies, such as the public transport network coordination optimization, the benefit analysis of the public transportation system, and so on. This paper first categorizes passengers transferring from rail transit to buses into two groups, namely, scheduled passengers and random passengers, and conducts the curve-fitting for the arrival time distribution accordingly. It is shown that the lognormal distribution has the best fitting performance for scheduled passengers, and the gamma distribution has the best performance for random passengers. Then, it develops a peak-hour average waiting time model for transferring passengers based on the passenger classification. Finally, it applies the proposed model to the bus line 519 at Longze station of Beijing to examine the accuracy of the model. The examination results demonstrate that the developed model can accurately estimate the peak-hour average waiting time of transferring passengers with a relative error less than 2.05％.

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Calculation of Time Value for Urban Public Travel with MNL model

FU Wei-wei, JIN Wen-zhou, LIN Fu-cheng

2010, 10(2): 148-152 .

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Travel time and costs should be considered in the sensitivity analysis of public transport transfer behavior and the formulation of public transport fares, while the value of travel time is the link of them. This paper first analyzes the multinomial Logit (MNL) model based on random utility maximization theory and quantifies the value of travel time with the simplified MNL model. Then, taking Beijing as an example, the paper estimates the travel time values for different income groups, with consideration of their travel time, travel costs, income, and other factors alike. In the final section, .the time value of urban public travel in Beijing is calculated with property analysis of public transport travelers and the average travel time weighting of different income groups. The result well matches the actual situation of Beijing.

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Multi-Ant Colony Algorithm for Optimal Stowage of Multi-Category Goods and Multi-Container

WANG Hai-xing,ZHANG Guo-wu,LI Zhen-jiang

2010, 10(2): 153-159 .

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Considering the optimal loading and volume, and the stowage with limitation, this paper analyzes several differences of the multi-ant colony algorithm for the current problem and TSP, namely, joint property, original note function, route construction rule, and formulation of feasible solution. Multi-Ant colony algorithm include three parts: ACA-INI, ACA-CONTAINER and ACA-VOTUME. Improvement on route construction rule and pheromone updating rule was adopted on the basis of former algorithm. An example was analyzed to demonstrate the correctness of the application of this model and algorithm. It is proved that multi-ant colony algorithm is efficient and feasible in solving optimal loading of multi-category goods and multi-container.

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Optimization Model and Algorithm for Bi-level Distribution Network of Ceramic Raw Materials in Ceramic Industrial Cluster Region

XIE Qing-chun,SHI Feng, QIN Jin

2010, 10(2): 160-166 .

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To meet the raw materials distribution demand of ceramic enterprises in the cluster region and improve the scale economic distribution service, the appropriate ceramic raw materials distribution network should be established. The bi-level distribution network in ceramic industrial cluster region is proposed in the paper. The service nodes in the first level are the large and professional distribution centrals, which satisfies the ceramic raw materials demands of the distribution centrals and some ceramic enterprises within theirs service range; The service nodes in second level is the distribution centrals established in some ceramic enterprises, and the ceramic raw materials demands of the itself and some other surround ceramic enterprises are satisfied. The optimization model for bi-level distribution network design is proposed in which the objective function is to minimize the location costs and transportation cost and inventory cost, the service quality is considered at the same time. A solution approach based on the simulated annealing algorithm is developed. Practical application denoted the optimization method operated rapidly and the result is rational. It provides a perfect decision-making support method for the design of ceramic raw materials distribution network in the ceramic industrial cluster region.

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Decision Making in Transportation Service Supply Chain under Two Different Commitment Times

NIU Lin-wei, WANG Chuan-xu

2010, 10(2): 167-173 .

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The supplier’s commitment time always influence the decision of the transportation service supply chain when the actual demand is unknown. Considering a delayed commitment and an early commitment, this paper presents decision models to determine the carrier’s transport price and the shipper’s transportation quantity under exogenous price and carrier pricing. The optimal results are compared between the overall decision-making and individual decision-making, delayed commitment and early commitment. It provides references for transportation service supply chain decision-making. It is shown that the profits of the transportation service supply chain under overall decision-making are larger than that under individual decision-making. It also finds that the carrier’s transport price affects the supplier’s commitment time, and the superiority is different between a delayed commitment and an early commitment under different transportation price.

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Emergency Materials Classification Method Based on Posterior Probability Support Vector Machine

XIA Ping,LIU Kai

2010, 10(2): 174-177 .

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Once emergency happened,the requirements for materials are numerous and complicated, the requirements are urgent and variational as well in. To impove the efficiency of emergency logistics,the rescuer need to classify the emergency materials. A novel method for emergency materials classification based on posterior probability support vector machine is proposed. The classification model for emergency materials is presented via PPSVM. This article took the materials importance;urgency and scarcity as the classified criterion, put the velues after being fuzzed as the input of PPSVM, selected the classification which is corresponding with the Max Posterior Probability as the output , the results of the classification are obtained finally .Experimental results demonstrate that the proposed method is feasible, it can solve the problem of emergency materials classification effectively.

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Coupling Passive GPS Tracking and Web-based Travel Surveys

DENG Zhong-wei,JI Min-he, CHEN Wen,SHI Bao-hong,ZHANG Zhi-hua, ZHANG Bo, WU Yi-min

2010, 10(2): 178-183 .

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In household travel surveys, one effective way to improve the }response rate and accuracy is reducing the respondents’ burden. This paper proposes a GPS and internet based survey method. The GPS data loggers are used to collect vehicle track data for accurate trip, route identification, and trip purpose, while the web-based surveys collect the personal／household information from the survey respondents. Because of the high spatiotemporal accuracy of GPS travel data, the requirement of exact travel time can be decreased, and the respondents’ pressure reduction can be achieved. Moreover, the respondents are allowed to choose their appreciate time for the online survey. All these decrease the negative effects from undesirable factors or conditions. A case study is conducted among the faculty of East China Normal University to test the proposed approach. Results indicate that the passive GPS and web-based survey techniques could significantly improve the accuracy and efficiency of travel data collection and drastically reduce respondents’ burden and survey costs. This approach has potential advantages for the application on HTS.

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Principal Components Analysis Based Evaluation on Level of Service for Urban Freeway Basic Sections

ZHENG Li, SONG Rui, LIU Jie

2010, 10(2): 184-189 .

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Level of service (LOS) of the urban freeway basic section determines the smoothness of the whole urban traffic system. To estimate the LOS of urban freeway more accurately, the paper first analyzes the traffic running characteristics, traffic composition structure, and alignment geometrical characteristics of urban freeway basic sections, and then establishes the evaluation system. LOS of the urban freeway basic section is calculated by principal components analysis via SPSS. Taking Lianhuachi west road as an example, the LOS of each basic section and the daily average LOS clustering results are obtained, as well as the integrated evaluation scores. The results show that the proposed method improves the traditional method on LOS determination of freeway basic section, and the clustering analysis classifies the LOS of each basic section more .

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Analysis for Train Control System of Qinghai-Tibet Railway Based on GPS and GSM-R

TANG Jian-guo

2010, 10(2): 190-194 .

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ITCS, which has been successfully applied in China Qinghai-Tibet railway, is one of the modern advanced wireless train control system. In this paper, the system function and structure of on-board control device are introduced. Based on the general procedures of FTA for reliability assessment, with the typical configuration and practical operation process, the fault mode of ITCS are defined and the fault tree is built accordingly, then based on the features of Markov process, the reliability derivation of and gate and or gate are realized for the quantitative calculation of the entire system. Finally, combined with the project implementation, the emergency response policies under certain fault state are detailed analyzed.

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