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25 June 2013, Volume 13 Issue 3 Previous Issue    Next Issue
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Forum about Comprehensive Transportation System
Systems Engineering Theory and Methods
Intelligent Transportation System and Information Technology
Systems Engineering Theory and Methods
Cases Analysis


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Forum about Comprehensive Transportation System

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Energy Consumption Driving Factors and Measuring Models of Regional Integrated Transport System SUN Qi-peng, JI Jiao, XU Cheng 2013, 13(3): 1-9.  Abstract ( )   PDF (814KB) ( )   To identify the energy consumption driving factors and measure their corresponding contributions in energy consumption, the paper classifies the factors into scale effect, structure effect and technique effect according the driving mechanism. It then analyzes the correlations between these factors by ASIF data structural principles and the time series regression. The contributions of these factors are measured via the expanded LMDI decomposition model based on the LMDI method. The result indicate that: (1) the impacts from scale effect and technique effect are weakening, while that from structure effect is increasing; (2) the transport supply structure needs to be further optimized, and there exists plenty of space for reducing the impact on energy consumption; (3) the energy efficiency has increased a lot in recent years, but its contribution to energy consumption is shrinking. Improving the transport intensity exerts significant effect on saving energy. The reliability of the models and its conclusions is proved by empirical studies, which provides scientific supports for the policy making of regional lowcarbon integrated transport. References | Related Articles | Metrics

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A Quantitative Analysis of Carbon Emissions Reduction Ability of Transportation Structure Optimization in China WEI Qing-qi, ZHAO Song-zheng, XIAO Wei 2013, 13(3): 10-17.  Abstract ( )   PDF (548KB) ( )   In order to develop a lowcarbon emissions transportation system, it is important to study the carbon emissions reduction ability of transportation structure optimization. Based on analysis of the impact of transportation structure on carbon emissions, this paper employed a quantitative approach and time series data (1989-2009) to analyze the effect of transportation structure on carbon emissions in China. In this study, a quantitative approach of the decomposition analysis and the impulse response function were combined. Measurements of the quantity change in carbon emissions caused by the transportation structure factor were obtained along with the responses of the carbon emissions to the impulse of the transportation structure optimization. The relationship between transportation structure and carbon emissions was discussed based on empirical results, including: (1) shortand longterm influence of transportation structure on carbon emissions; (2) comparative analysis of transportation structure and other principal factors; (3) the dynamic interaction mechanism between transportation structure and carbon emissions. The outcome of this study proved to be valuable for researchers and decision makers in this field. References | Related Articles | Metrics

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Self organization Evolution of Comprehensive Passenger Transportation System SONG Cheng-ju, ZHANG Ya-ping, WU Biao 2013, 13(3): 18-24.  Abstract ( )   PDF (1360KB) ( )   Comprehensive passenger transportation system is an open but complex system. Therefore, it is hard to understand the evolution process for the system. This paper uses the selforganization theory to analyze the evolution mechanism of comprehensive passenger transportation system. It elaborates the applicability of selforganization theory to the comprehensive passenger transportation system with consideration of the passenger turnover as the system variables. The logistic model is used to establish selforganization evolution model, and the simulation analysis is conducted. Results show that comprehensive passenger transportation system is able to achieve balance status through selforganizing. The time to be balanced is associated to the initial state, and it has a positive relationship with the intrinsic growth rate. The balanced state has positive relationship with its own system capacity, and there exists close relationship between the balance and the influencing coefficient of transport modes. Therefore, comprehensive passenger transportation system qualifies with the characteristics of selforganization. References | Related Articles | Metrics

Systems Engineering Theory and Methods

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A Meta-synthesis Method for Transportation Demand Forecasts ZHU Wei, HAN Bin 2013, 13(3): 25-32.  Abstract ( )   PDF (735KB) ( )   Nowadays, it is necessary to improve theory and methods for transport demand forecasting in China since the country is now different from many developed countries—in its stage of rapid urbanization. To forecast the transport demands more appropriately and consequently comprehend the transport demands more deeply, a metasynthesis based method and corresponding work procedure for transport demand forecasting is proposed in this paper. The method is from the aspect that a transport system is categorized into an open complex giant system and the transport demand forecasting is considered as a complex problem. The feasibility of the method is proved in its application to a passenger flow forecasting for intercity railways system in Zhejiang province of China. The practice shows that the method could result in more accurate and reliable results as well as a good performance for use. References | Related Articles | Metrics

Intelligent Transportation System and Information Technology

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Traffic Flow Forecasting Based on Growing Self-organized Neural Network Group LV Jin, ZHAO Xiang-mo, FAN Hai-wei, WONHAM W M 2013, 13(3): 33-39.  Abstract ( )   PDF (2304KB) ( )   To enhance the capacity of dynamic study and realtime forecasting on urban traffic flow, this paper proposes a type of growing selforganized neural network group (GSNNG). A complex artificial neural network (ANN) is introduced into some easytrained ANNgroups, and the dynamicgrowing selforganized algorithm is adopted to avoid the ANN damages to the acquired knowledge when it learns some new ones. The algorithm is able to maintain the stability of the whole ANNgroups, as well as the efficiency and a reasonable scaleconfined. The GSNNG solves the ANN’s problem that new knowledge affects on the old ones, which had more dynamic knowledgeincreasable, errorsselfrepairing and adapting capacity. Simulation results show that the GSNNG produces higher forecasting precision and stronger dynamic performance in systemidentification and traffic flow forecasting. The method is fit to the complex systems which need continual dynamicstudy. References | Related Articles | Metrics

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An Optimization Method of Traffic Signal Control Based on Cooperative Vehicle Infrastructure System ZHANG Cun-bao, RAN Bin, MEI Zhao-hui, ZHANG Pei-ling 2013, 13(3): 40-45.  Abstract ( )   PDF (601KB) ( )   The cooperative vehicle infrastructure system (CVIS) is used to monitor individual vehicles realtime status, which provides new data source and technical supports for traffic signal control. The shortcomings of the existing traffic signal control methods are analyzed, and an improved optimization procedure for road intersection signal control is presented based on the CVIS using the rolling timewindow forecasting. The saturation degree is selected to be the indicator of signaling control effect, and the optimizing method and models for signal control are developed, considering the influence of speed guidance to individual vehicles. Simulation experiments are conducted using VISSIM. The results indicate that the proposed method is more effective than the induced control method. The average delay and stops decrease are significant under both low and high traffic demands. References | Related Articles | Metrics

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Estimating Traffic Flow Models for Urban Expressway Based on Measurement Data 2013, 13(3): 46-52.  Abstract ( )   PDF (1471KB) ( )   The existing traffic flow models, including fundamental diagram and threephase traffic theory, are conducted based on the highway traffic flow data. Because there exist significant differences between the highway and urban expressway traffic characteristics, the traffic flow models which developed based on highway traffic flow data, are not always suitable for the traffic flow conditions of the urban expressway. The measurement data of the urban expressway is used in this paper to develop the traffic flow models. The traffic flow models of speedoccupancy, traffic flowoccupancy, and speedtraffic flow are proposed using the linear regression analysis. The least square method is adopted to estimate the model parameters, and the significance of model fitting and parameters is tested by Fand Ttest. Some key issues are investigated, such as the traffic states splitting and impacts between traffic flow parameters. The results demonstrate that the developed traffic flow models are feasible for the shortterm traffic flow prediction and the traffic flow identification. References | Related Articles | Metrics

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Research on the Time Characteristics of Drivers’Emergency Response Operation under Urban Road Environment WANG Chang, FU Rui, YU Peng-cheng 2013, 13(3): 53-59.  Abstract ( )   PDF (783KB) ( )   Aiming at the driver’s stress operation time under urban road environment, test platform based on virtual reality technology is established, and 28 driver’s stress operation time in different scene is analyzed. The result shows that unskilled driver’s stress operation time is less than the skilled driver drivers, and whose operation time is stable. The young driver’s operation time is least, which is the most stable one. Besides, with the increasing vehicle speed, diver’s stress operation time shows downward trend, and the best fitting function relationship is the logarithm. The logarithm forecasting model is formulated considering driver’s experience, age and vehicle speed, which can realize an accurate prediction for driver’s stress operation time, and the predicting accurate rate is calculated to be 98.37%. References | Related Articles | Metrics

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Empirical Study and Modeling of Variable Message Signs on Route Choice Behavior WANG Wei-wei, ZHAO Xiao-mei, LI Xin-gang, XIE Dong-fan 2013, 13(3): 60-64.  Abstract ( )   PDF (456KB) ( )   Variable message signs (VMS) frequently influence driver’s route choice behavior through providing instantaneous traffic information. It is one of the most important components of intelligent transportation system (ITS), and an efficient method to release traffic congestion. To quantitatively analyze the effects of VMS on drivers’ route choice, this study makes the SP survey on drivers that have more than one year driving experience. Then, the data are analyzed by SPSS20.0, and the ordinal classification Logit models are used to reflect the route choice behavior. Finally, the conclusion is presented: route choice behavior according to VMS is highly related to driving style, travel time and accuracy of VMS. References | Related Articles | Metrics

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Consistent Fusion of Traffic State Decision Information Based on IFS YIN Jun-song, YAN Qi-peng, LIU Lan, MA Ya-feng 2013, 13(3): 71-77.  Abstract ( )   PDF (421KB) ( )   Considering the multisource traffic information with fuzziness and timevarying characteristics, this paper introduces the intuitionistic fuzzy set theory (IFS) to establish consistency fusion algorithm of multisource traffic information. It integrates sensor detection information and artificial information to recognize on realtime traffic status. To solve the problem, it is difficult to determine in the nonmembership function of the IFS. The construction method of the membership function is introduced, and the dual membership function is used to construct the intuitionistic fuzzy numbers. The support degree function is established using the membership degree and the nonmembership degree, to quantify the degree of consistency in decisionmaking information. The higher the support degree of decisionmaking information is, the greater is the weight degree of integration. The weight is dynamically updated with the changes in the decisionmaking information. Finally, the steps is given for the traffic state decisionmaking information fusion algorithm, and an example is used to illustrate the effectiveness of the algorithm. References | Related Articles | Metrics

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Queue Length Estimation Based on Floating Car Data ZHUANG Li-jian, HE Zhao-cheng, YE Wei-jia,CHU Jun-fei, DENG Ling-li 2013, 13(3): 78-84.  Abstract ( )   PDF (852KB) ( )   Queue length is an important index to evaluate the operation efficiency of signalized intersections and reflect the traffic status of intersections. Conventional queue length estimation models are mainly based on loop detectors and idealistic assumptions. This paper proposes an online queue length estimation method at signalized intersections with lowsamplingrate floating car data. The core of the method is estimating the maximum queue length considering the position of the last floating car. Using fixed time intervals, the method is datadriven and consists of map matching, lowspeed point statistics, determination of the last floating car and queuing correction. The ground test shows the precision of the method is closely related to the floating car rate. At trunk road intersections with high floating car rates, the expected accuracy can be obtained. For peak hours, the mean absolute error (MAE) within 30 meter is acceptable and of great value. References | Related Articles | Metrics

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Face Verification Algorithm Using the Bag of Visual Words Model LIU Shuo-yan, WANG Xiao-dong, WANG Bing, LV Xiao-jun 2013, 13(3): 85-90.  Abstract ( )   PDF (673KB) ( )   With the development of train ticket realname system, manual identity verification method no longer meets the actual demand. Therefore, this paper proposes a face verification method based on the bagofvisual words model. This approach aims to automatically identity the verification based on face matching. First, the scale invariant feature transform (SIFT) feature is extracted for each image. Then, the bagofvisual words model is used to construct the face typical feature. The study also trains the SVM classifier, which models the similarity between two images of an individual and the difference between two individuals. Finally, the passenger image and his ID card image are classified to determine whether they are belonging to the same person or not. The experimental result indicates that the proposed algorithm is able to effectively accomplish face verification, especially perform well in the circumstance with low image quality, and uncontrollable light and bright. References | Related Articles | Metrics

Systems Engineering Theory and Methods

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Time Gap Modeling Using Mixture Distributions under Mixed Traffic Conditions DUBEY Subodh Kant，PONNU Balaji，ARKATKAR Shriniwas S 2013, 13(3): 91-98.  Abstract ( )   PDF (787KB) ( )   The timegap data have been modeled through noncomposite distribution up to a flow level of 1 800 vph. It has been found that these models are not capable of modeling time gap data at higher flow levels. Some composite distributions have been proposed to overcome this problem. But, due to the fact that the calibration of model parameters used in composite distributions is tedious, there use may be relatively limited. In this paper, five mixture models namely Exponential+Extreme-value (EEV), Lognormal+Extreme-value (LEV), Weibull +Extreme-value (WEV), Weibull+Lognormal (WLN) and Exponential+ Lognormal (ELN) have been used to model time gap data for flows ranging from 1 900 vph to 4 100 vph. Two types of goodnessoffit tests namely cumulative distribution function (CDF) based and twosample (Cramervon Mises test) & Ksample (AndersonDarling test) based tests were performed. Among all the five models, Weibull+ Extreme Value was found to be the best mixture model for modeling time gap data as it performed consistently well in Cramervon Mises test and Ksample AndersonDarling test. References | Related Articles | Metrics

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A Calculation Method and Its Application of Bus Isochrones HU Ji-hua,CHENG Zhi-feng,ZHONG Guang-peng,HUANG Ze 2013, 13(3): 99-104.  Abstract ( )   PDF (2054KB) ( )   Bus isochrones indicate the maximum scale of bus system can extend during one time interval. A calculation method of isochrones is proposed in this paper and it can be applied to the analysis of public transport accessibility. The travel process by bus is analyzed and divided into five parts: walking to the bus stop from departure, waiting for buses, boarding buses, transfer and walking to the destination. Specific calculation methods of time cost are proposed for each part, respectively. Then, the isochrones are obtained by the grid method and the inverse distance weighting method. The bus GPS data of Guangzhou, China is used to draw the isochrones maps and to demonstrate the Tee mall. Furthermore, the spacetime accessibility is measured in the covering area of a unit time isochrones and the accessibility differences of different directions are then analyzed through profiles. References | Related Articles | Metrics

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Intercity Rail Transport Pricing Strategy Based on Efficacy Coefficient Method WU Ke-qi, MAO Bao-hua, WANG Yong-liang, SUN Quan-xin 2013, 13(3): 105-110.  Abstract ( )   PDF (904KB) ( )   By utilizing the efficacy coefficient method, this study proposes a multicriteria modeling approach for the reasonable pricing decision of intercity rail passenger transport. The proposed model aims at minimizing the average travel time and energy consumption per passengertrip for an intercity rail passenger transport system. It is empirically confirmed that the variation of the ticket price imposes significant influence upon the transport ratios of different travel modes. It is proved that the average travel time per passengertrip and the system energy consumption declines with the reduced fare. As for the operation of rail passenger transport system mentioned in the case study, if its fare is adjusted to 55.8 yuan/passengertrip, the average travel time and energy consumption per passengertrip decrease by 7.8% and 2.1%, respectively. This study is able to assist the sensible decisionmaking of ticket price, which can also effectively promote the operation efficiency and sustainability of an intercity rail transport system. References | Related Articles | Metrics

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Competition Model of Container Road Transportation Market DONG Gang 2013, 13(3): 111-114.  Abstract ( )   PDF (358KB) ( )   Considering two major factors of truck transportation service and freight forwarding quote to the sensitive shipper, this study proposes a market competition model of container road transportation. The model involves more competitive truck operators and one freight forwarder and solves the game equilibrium through backward induction. The results indicate that with the application of valueadded service, truck operator receives lower profit due to burden cost of the upgrading service. However, the demand satisfaction of truck transportation market significantly increased, and the overall profit of truck operator and freight forwarder witnessed an increasing trend. Therefore, to motivate valueadded service of truck operator, the reasonable benefit distribution mechanism needs to be established between truck operator and freight forwarder, which provides benefits for the healthy development of truck operator and container transportation chain. References | Related Articles | Metrics

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A Pricing Method for Smallsize Cargo Express Service in Long Distance Highway Transportation SUN Xi-an, LI Xue-fei, CHENG Hua 2013, 13(3): 115-120.  Abstract ( )   PDF (432KB) ( )   After a survey of 10 longdistance highway passenger transportation stations in Beijing, we found that 50% of the stations do not provide express services for smallsize cargos. Passenger stations that provide such services have a low profit.The main reason is that there is no effective pricing method for smallsize cargos. To address this critical need, we first look at the operating costs of all the parties involved with smallsize cargo express services. According to the customers’ freight transport demand function, we propose a model for determining the price for smallsize cargo express services with an objective function of maximizing the station’s revenue. Based on the model, the necessary conditions are specified in order for passenger stations and companies to operate such businesses. Furthermore, a method of fitting the transportation demand function is provided based on the actual operations and services. Finally, a numerical example is given to illustrate the application of the proposed pricing method for smallsize cargo express services. References | Related Articles | Metrics

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Traffic Flow Forecasting Based on Large Scale Traffic Flow Data SUN Zhan-quan, LIU Wei, ZHU Xiao-min 2013, 13(3): 121-125.  Abstract ( )   PDF (367KB) ( )   With the development of traffic informatization, increasing amount of traffic data can be collected. How to make most of the traffic data to forecast traffic flow is a crucial work of the intelligent transportation systems (ITS). To resolve this problem, this paper proposes a sampling method based on the combination of stratified sampling method and kmeans clustering. The support vector machine (SVM) based on sequence optimization method is used to forecast traffic flow parameters. The analysis results show that the sampling quality based on the proposed sampling method is reformed. The forecasting precision based on the SVM also gets improved. It proves that the method is efficient to solve largescale traffic forecasting problems. References | Related Articles | Metrics

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Freight Station Location of Inland Port Semi-Trailer Swap Transport Organization ZHONG Hui-ling, WU Cong, ZHANG Guan-xiang, CAI Wen-xue 2013, 13(3): 126-131.  Abstract ( )   PDF (758KB) ( )   Semi-trailer swap transport is an advanced way to organize road transport, because of the advantages of intensive, high efficient and low carbon consumption. This paper proposes the semitrailer swap transport model for inland ports. The selection steps are determined and the mathematical model of the freight station location is developed for the inland port semitrailer swap transport organization. The solution algorithm is then proposed based on the genetic algorithm. Then, a simulation model is formulated base on Arena to evaluate the location program. Finally, the paper takes one port of Guangdong province, China as a case study. The semitrailer swap transport model is used to locate the freight station. The comparison between the proposed model and the traditional container transport model is conducted using simulation software. References | Related Articles | Metrics

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Arriving Passengers’ Offsite Mode Choice Model of Railway Passenger Transport Hub YUN Liang, JIANG Yang-sheng, XIE Han 2013, 13(3): 132-137.  Abstract ( )   PDF (462KB) ( )   Passenger’s offsite mode choice behavior is one of the key issues related to the rational traffic resource allocation. The existing mode choice models consider less on the level of service factors. To solve this problem, this paper first analyzes the offsite mode choosing mechanism of arriving passengers, and defines the service level expectations as service level factor variables. Then, it introduces the service level expectations variables into the utility function and formulates the improved offsite mode choice NL model. Finally, the model is validated with the survey data which is obtained in Chengdu East Railway Station, China by programming. The results prove the good accuracy of the improved mode choice model. However, the fitted value of public transport is slightly lower than the survey value. This is possibly because the mathematical expectation is used as the service level expectations values. Therefore, there are still some areas for improvement in the service level expectations index value selection. References | Related Articles | Metrics

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Long term Forecasting Model of Railway Container Freight Volume YAN Wei, ZHU Xiao-ning, WANG Li 2013, 13(3): 138-143.  Abstract ( )   PDF (536KB) ( )   A railway container freight volume forecasting model is proposed in this paper based on econometric techniques, which can accommodate multiinfluencing factors. Some influencing factors are considered in this forecasting model, such as longterm trends of the national economy, industrial structure, layout of production, railway transport structure, level of the consumption, etc. All these factors are respectively set to be endogenous variable, exogenous variable or prior endogenous variables that based on characteristics of different factors. Then the equations formation of the forecasting model is present. In the last section, the paper estimates and testes (including global and final tests) the proposed model. Test results show the error rate of the model is small, and has high precision. Thus the model can be used for forecasting of railway container freight volume, and it also provides basic data for planning and development of railway container transportation. References | Related Articles | Metrics

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Design and Organization of Differentiation Transport Product of Railway WANG Bo, HE Shi-wei, WANG Bao-hua 2013, 13(3): 144-150.  Abstract ( )   PDF (534KB) ( )   With the diversification of logistics service development and the intensification of competition, the railway needs to implement differentiation strategy to improve its competitiveness. The optimization in the process of traffic organization is an important link to ensure the differentiation. Under the restriction of different service levels, this paper proposes the optimization model of the design and organization of differentiated transportation products of railway, with the object function of minimum total operation cost. Taking the number of optional route for each traffic flow into consideration, this study gets the optional route set for all the flows at first, and then selects a suitable route for each traffic flow. According to the characteristics of the model, this paper designs a kind of twostage heuristic algorithm to solve it. Finally, this paper devises a numerical example to test and verify the model and algorithm. The results shows that the optimization ideas and methods proposed have a certain referential significance to the railway transportation organization. References | Related Articles | Metrics

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Simulation Evaluation Model on Driving Risk of Expressway Work Zone WU Biao, XU Hong-guo, DAI Tong-yan, SONG Cheng-ju 2013, 13(3): 151-156.  Abstract ( )   PDF (569KB) ( )   Based on the integration of single vehicle risk model and macro traffic flow parameters, this paper proposes an evaluation model on driving risk of expressway work zone. Considering the vehicle driving characteristics, the evaluation model is developed based on selection of the risk measurement index of vehicle deceleration and macro traffic flow parameters including average speed, mean occupancy ratio and speed variation. The method of traffic simulation is adopted to simulate traffic flow in expressway work zone, and the test data is collected from simulation. The multiple linear regression model is developed to describe the relationships between the average driving risk level and macro traffic flow parameters. It shows that the coefficient of variability of speed significantly impact the level of average driving risk. References | Related Articles | Metrics

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Pedestrian Physical Consumption Quantitative Method and Applications JIN Guang-hao, LIU Xiao-ming, BIAN Yang 2013, 13(3): 157-162.  Abstract ( )   PDF (600KB) ( )   Physical consumption and pedestrian flow rate are the leading influence factors in reflecting the level of service of pedestrian interchange crossing facilities. Aiming at the physical consumption of walking up and down the stairs, this paper obtains pedestrian oxygen consumption with the oxygen consumption model. It converts physical consumption into walking distance equivalently according to the equivalent relationship between the oxygen consumption. The equivalent walking distance and pedestrian flow rate threshold corresponded to each pedestrian feeling level is confirmed by twostepcluster method combined with actual survey. Then, based on the threshold and combined with the level of service polymerization model, the evaluation on the level of service of pedestrian interchange crossing facilities can be accomplished. As the result of this study, the following conclusions are drawn: the equivalent walking distance of the same distance up and down stairs and the actual detouring distance can make the same perception on pedestrian. The equivalent walking distance can well reflect the actual feeling of pedestrian physical consumption. The pedestrian perception from using footbridge and subway are respectively equivalent to 50 m and 35 m. References | Related Articles | Metrics

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Calculation Model for Passenger Assembling on OneplatformtransferStation Based on Timetable Coordination WANG Fei, SUN Quan-xin, MAO Bao-hua, FENG Xu-jie 2013, 13(3): 163-169.  Abstract ( )   PDF (1269KB) ( )   With full consideration of the timetable coordination, this paper calculates the assembling passengers at a oneplatformtransfer metro station with varied intervals of trains’arrivals. The Anylogic software is used to simulate the actual transferring behavior of passenger and the results of the maximum number of assembling passengers is close to the model calculated results, which proves the validity of the calculation model. The numerical example shows that the maximum number of assembling passengers decreases with the growth of trains’ arrival intervals from two different lines which have the same departure frequencies. The maximum number of assembling passengers reaches the maximum when the trains arrive at the same time. Hence the maximum number of assembling passengers decreases when the arrival intervals increases by 30 seconds. The maximum number of assembling passengers decreases to the lowest when the arrival interval expands to 150 seconds. References | Related Articles | Metrics

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Models and Calculation Methods for Expected Traffic Delays at Signalized Intersections CHEN He-ming, LI Shuo, GAO Yan, LI Wei-rao 2013, 13(3): 170-177.  Abstract ( )   PDF (542KB) ( )   Previous traffic delay models at signal control intersections are usually formulated according to a single approach. This paper presents the delay analysis methods for vehicles at signal control intersections which are referred to all the approaches in the same signal cycle. Under the nonsaturated traffic conditions of intersection approaches, the microscopic traffic delay model are proposed and deduced. It shows the dynamic relationship between the expected signal intersection delay and the parameters of signal control, vehicle arrival rate and the queue length. The Changsha Jiefang west Rd/ Jianxiang Rd intersection is taken as an example to calculate the intersection delay by the model. The results are compared with the calculation results of HCM2000 and spot sample method, which show that the deduced model can be used as an effective way to analyze and evaluate the traffic delay at the signalized intersection. References | Related Articles | Metrics

Cases Analysis

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Freeway Traffic IceDetecting and Warning Method in Cold Region ZHOU Fang-ming, WANG Gang, WANG Lin, LIU Dong-mei, YI Qian 2013, 13(3): 178-182.  Abstract ( )   PDF (1017KB) ( )   Ice and snow impose harmful effects on freeway traffic in cold regions, which significantly affects road traffic safety. This paper introduces the ice and snow detecting and warning method. An ice and snow formation model is established based on the hierarchical highway thermal conductivity theory. The study collects the road physical attributions (such as longitude, latitude, thermal conductivity, etc.) and meteorological data (including air temperature, precipitation, dew temperature, etc). The automatically running modal is developed, which forecasts road surface state by three or six hours in ahead. It supports the traffic regulation, deicing machinery redeployment and the delimiting of working area. The Saiguo highway of Xinjiang Province of China is taken as an example. The results indicate that the number of traffic accidents is lower than the predicted value from traffic safety evaluation report issued two years ago. The number of death is also much lower than the prediction value. References | Related Articles | Metrics

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Catchment Area Analysis of Beijing Transit Stations WANG Shu-wei, SUN Li-shan, RONG Jian 2013, 13(3): 183-188.  Abstract ( )   PDF (560KB) ( )   Reasonable setting of transit station catchment areas lays the foundation for predicting the transit station travel demand and designing feeder measure layout. The paper aims to overcome some shortcomings in previous researches such as seldom considering the characteristics of local road networks, as well as the problems of catchment area coincidence and potential catchment areas determination. Based on an passenger investigation, the paper presents a method to determine the catchment area with consideration of the grid type road network characteristics. With the introduction of the Thiessen polygon, it solves the coincidence problem of catchment areas, and then presents a delineating method for potential catchment area. Finally, the Geographic information system is used to establish the catchment area of Beijing Transit stations. Several feeder measure layout schemes are also generated for each station considering its catchment area characteristics. Research findings provide a theoretical basis for the future work of transit station catchment area such as land use, travel demand forecasting and feeder measure layout. It may also assist to enhance the operation efficiency of urban public transportation system in the long run. References | Related Articles | Metrics

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Evaluation on Highway Networks in China’s Key Areas LIU Dong, JIN Feng-jun 2013, 13(3): 189-195.  Abstract ( )   PDF (837KB) ( )   Some key areas in China are highly urbanized, economically developed and population concentrated regions which also generate huge highway transportation demand. Because of the unbalanced regional development, there exist huge differences among distinct key areas’ highway networks. According to the regional planning published by the central government, this study takes 27 typical key areas in China as the objectives and selects nine indicators reflecting the scale, quality, accessibility and traffic volume of highway networks. It finally develops an integrated evaluation model. The 27 key areas’ highway networks are evaluated and divided into three classes of area. In the last section, this study selects some underdeveloped areas as examples by five typical indicators: the density of highway network, average technical level, average pavement level, connectivity of countylevel node, and the percentage of villages connected by asphalt or cement road. It then provides a basis for optimization and upgrading of the highway networks in these underdeveloped areas. References | Related Articles | Metrics