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Journal of Transportation Systems Engineering and Information Technology

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    25 December 2019, Volume 19 Issue 6 Previous Issue    Next Issue
    Decision-making Forum
    Forum about Comprehensive Transportation System
    Intelligent Transportation System and Information Technology
    Systems Engineering Theory and Methods
    Cases Analysis
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    Decision-making Forum
    Judgement on New Technologies with Contents in Transportation Development
    WANG Qing-yun
    2019, 19(6): 1-5. 
    Abstract ( )   PDF (292KB) ( )  

    Transportation and its technologies are key issues of systems engineering that need to be deeply investigated. Firstly, this paper analyzes the relationship between the application of new technologies and the development of transportation based on the correlation between technology and economic development. Then this paper systematically proposes the concepts of new transportation technologies, technology contents, and the evaluation methods of the application of these technologies, and concludes that the application of new technology should aim at improving transportation efficiency and quality. From the point of view of system engineering, it is concluded that the key technologies of transportation systems are mainly embodied and concretized in five aspects: transportation infrastructures, means of transport, loading equipment, transportation organization and management, and service level. Finally, the application of several new technologies in the field of transportation is introduced.

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    Benefits of Common Distribution to Urban Freight Transportation System
    LU Hua, YUAN Min, LIU Yu-xia, DU Zhi-ping
    2019, 19(6): 6-12. 
    Abstract ( )   PDF (543KB) ( )  

    Based on the six factors of urban GDP, transport infrastructure, freight volume, freight vehicle scheduling, energy and environment, the dynamic model of urban freight transportation system is constructed, which compares changes on the congestion, transportation costs, energy saving and emissions reductions of freight transportation system before and after the implementation of common distribution. Taking Jinan City as an example, and the results show that with the increase of loading occupancy and average transportation distance, the marginal revenue of implementing common distribution is decreasing, and the peak-to-night adjustment of delivery time also has a significant impact. The overall efficiency of the joint distribution is optimal under the load-carrying rate of [70%, 80%], the average shipping distance of [70, 80] km, and the distribution day- to- night ratio of [6∶4 , 7∶3] . However, energy saving and emission reduction benefits can be further improved by increasing the proportion of new energy trucks, the result shows that every 20% increase of using new energy trucks will bring about an average reduction of 30% in energy saving and emission reduction of freight transportation systems.

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    Evaluation on Subsidy Policy of Public Transport Ticket Considering Elderly Travel Behavior
    YAO En-jian, YAN Zheng, HUAN Ning
    2019, 19(6): 13-19. 
    Abstract ( )   PDF (405KB) ( )  

    The current free public transportation policy for the elderly in Beijing guarantees their daily trips, which has induced problems of unnecessary travel, peak travel, and impersonated travel. Given the differences of travel purposes and distance and the characteristics of travel behaviors of the elderly, we construct a multinomial Logit (MNL) model of travel mode and tests the precision of the MNL model based on the data of the fifth comprehensive traffic survey in Beijing. We analyze the impact of two subsidies on the sharing rate of different modes of travel by using MNL model, and evaluate the effects from the utilization rate of public transport capacity, government subsidies and public transport expenditure of the elderly. The result shows that, compared with the current policies, both policies can effectively regulate the travel behavior of the elderly. Meanwhile, the peak subsidy policy can alleviate the pressure of government financial subsidy and increase the public transport expenditure of the elderly, and stepped subsidy policy can improve the social welfare of the elderly, but it may result in a substantial increase in government financial subsidy expenditure.

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    Forum about Comprehensive Transportation System
    Meso-level Vehicle Emission Model Based on Road Section Characteristics
    WU Ke-han, ZHAO Yi-xin, TANG Xi-ru
    2019, 19(6): 20-25. 
    Abstract ( )   PDF (327KB) ( )  

    The accurate calculation of vehicle emissions is the prime behind developing the controlling methods of vehicles pollution. In order to improve the accuracy of the emissions model, the paper proposed a concept of low speed percentage. A new meso-level vehicle emissions model based on normal VSP model was built in this paper. More influence factors of road characters were introduced into the model, including vehicle average speed, road length, road level and the low speed percentage. The model was built with multiple regression analysis. The comparison results show the proposed model has a higher precision than the normal VSP model. In consideration of the new factors included in the proposed model were easily to access, the model could be used in the large-scale estimation of urban vehicle emissions. The proposed model is meaningful for improving the accuracy of vehicle emissions model and developing the controlling methods of vehicle pollution.

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    Effectiveness of Floating Parking Price Based on Multi-agent Simulation
    QIN Huan-mei, ZHENG Fei, LIU Zhuo, LIU Shu-li
    2019, 19(6): 26-31. 
    Abstract ( )   PDF (365KB) ( )  

    With the rapid growth of urban motor vehicle ownership, formulating reasonable parking price to alleviate the parking problem is increasingly important. Based on parking survey data in urban business district, the multi- agent modeling method is adopted to build a simulation environment. Then behavior decision-making rules for the travelers’parking process are built through programming, and the simulation platform for curb parking under time-varying parking price is established. Finally, the implementation effect of time-varying parking price is analyzed. The findings show that the implementation of the time-varying parking price not only makes the utilization of parking resources more balanced and reduces the cruising time for parking, but also increases the vehicles speed on surrounding roads. The study can provide decision-making suggestions for improving parking efficiency and alleviating regional traffic congestion.

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    Intensive Parking Lot Scheduling Strategy Based on Time and Energy Consumption Weights
    RANWen-xue, YANG Li-fan,WANG Yan, LIU Sen
    2019, 19(6): 32-37. 
    Abstract ( )   PDF (399KB) ( )  

    Planar-dense parking is a brand-new parking scheme, which uses four-way shifting equipment with parking pallet to realize dense parking function. In order to research its scheduling problem, an improved shortest path algorithm is used to find out the shortest comprehensive path for the vehicle scheduling of any parking place in a planar-dense parking lot. In particular, time weight and energy consumption weight are introduced as different customers have different preferences for time and cost, and the actual situation that the energy consumption is different when the motor is no-load and full-load will lead to different dispatching costs. Based on this, a mathematical model is established. The experimental results verify the feasibility of the model through simulation. The simulation results show that the vehicle dispatching model can be used in the outbound dispatching of dense parking lots, which can save energy consumption and reduce costs on the basis of ensuring reasonable outbound time with the goal of economic and environmental protection. This study will contribute to the popularization and application of plane-dense parking lot.

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    Intelligent Transportation System and Information Technology
    Model of Acceptance of Unmanned Buses Based on UTAUT
    CHEN Jian, LI Rui, FU Zhi-yan
    2019, 19(6): 38-44. 
    Abstract ( )   PDF (398KB) ( )  

    There is a lack of quantitative description on the acceptance of unmanned buses. Aiming at this problem, based on the integrated technology acceptance model, this paper explores the acceptance of passengers from both intentions and behaviors. The acceptance model of unmanned bus passengers is constructed. Using the estimation of SEM to analyze the quantitative relationship among the influencing factors, and the effect of each factor on the intention and behavior of using unmanned buses. Finally, the model is applied to the case of Chongqing bus travelers. The results show that perceived risk (-0.89***) and individual innovation (0.72***) are most significant for unmanned bus use intentions. The intention of using unmanned buses plays a decisive role in the actual behavior of using unmanned buses (0.98***). The significant differences in the regulation of age, gender, and education level on various influencing factors were analyzed.

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    Morphous Detection and Deep Learning Based Approach of Vehicle Recognition in Aerial Videos
    PENG Bo, CAI Xiao-yu, TANG Ju, XIE Ji-ming, ZHANG Yuan-yuan
    2019, 19(6): 45-51. 
    Abstract ( )   PDF (551KB) ( )  

    In order to extract traffic information accurately from a regional perspective, a vehicle locating and classifying method for UAV videos was proposed combining morphous detection and deep convolutional networks. Firstly, target candidate extraction algorithm was designed based on morphous detection, thus a benchmark image library for deep learning was constructed containing 244 520 vehicle samples from UAV videos. Then, AlexNet was rebuilt by adding convolutional and pooling layers and adjusting network parameters, etc., thus a modified model AlexNet* was put forward. At last, vehicle recognition method fusing candidate extraction and AlexNet* was established. Validation analysis indicate that AlexNet* achieves an average F1 score of 85.51% in terms of image classification, outperforming AlexNet (82.54%), LeNet (63.88%), CaffeNet (46.64%), VGG16 (16.67%) and GoogLeNet (14.38%), and the proposed vehicle recognition method averagely obtains accuracy of 94.63%, repeated detection rate of 6.87% and missing detection rate of 4.40% for car and bus detection, which can effectively identify UAV objects.

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    Redesign and Experimental Evaluation of Cooperative Adaptive Cruise Control System
    HUA Xue-dong YANG Jian-qiang,WANGWei
    2019, 19(6): 52-60. 
    Abstract ( )   PDF (604KB) ( )  

    The primary objective of this paper is to improve the traffic mobility and stability by modified the CACC system design. An extension of Newell’s car-following model with consideration of CACC is developed. The dynamics of the proposed CACC car- following model is then analyzed, and the string stability condition is obtained. Various connectivity structures in heterogeneous platoons comprised of CACC and non-CACC vehicles are considered and compared as well. Numerical experiment is demonstrated to further study the in fluence of CACC vehicles on traffic dynamics during starting, braking and traffic incident. The results reveal that with appropriately designed model parameters, CACC can improve the string stability of traffic on one hand. On the other hand, the introduction of CACC vehicles makes travelling safer and more comfortable. Moreover, as the connectivity structures of CACC vehicles in heterogeneous platoons can affect the performance of traffic mobility, CACC vehicles should use information from selective preceding vehicles.

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    Analytical Relationship Between CACC Headway and Stability of Mixed Traffic Flow
    QIN Yan-yan, HU Xing-hua, HE Zhao-yi, RAN Bin
    2019, 19(6): 61-67. 
    Abstract ( )   PDF (441KB) ( )  

    This paper studies influence of cooperative adaptive cruise control (CACC) headway on stability of mixed traffic flow with different CACC proportions. Then it can provide reference for design of CACC headway. The optimal velocity model (OVM) was used for the car- following model of manual vehicles, while the model calibrated by PATH' s experiments was employed for CACC vehicles. Based on transfer function theory, stability criterion of the mixed traffic flow was derived. Then stability charts with respect to CACC proportions and equilibrium speeds were calculated. The variable design strategy for CACC headway was proposed by analyzing the analytical relationship between CACC headway and critical CACC proportion that will maintain stable mixed flow under any speed. The numerical simulations were also performed to validate correctness of the proposed variable strategy for CACC headway. The results show that the designed values of CACC headway decrease with the increase of CACC proportions under the proposed variable strategy. This avoids impacts of larger values of CACC headway on capacity improvement of the mixed traffic flow. Moreover, the mixed traffic flow can be stable for any speed when the CACC proportion is more than 35%. This paper contributes to the reference for theoretical design of large-scale real CACC implements.

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    Optimal Layout of Subway Station Information Query Platform Considering Passenger Flow and Node Importance
    XU Hui-zhi, ZHAO Xiao-hong, WU Teng-fei
    2019, 19(6): 68-76. 
    Abstract ( )   PDF (490KB) ( )  

    Metro stations are mostly underground space and have complex structures. Induction facilities should provide more convenient and efficient services for passengers. Based on the existing passenger flow model, considering the importance of nodes, the existing model is revised, and the location selection model of passenger guidance facilities is constructed to maximize the amount of regional guidance information. Taking Xizhimen Station of Beijing Metro as an example, this paper investigates the status quo of induction facilities in metro stations, designs questionnaires to analyze the effectiveness of induction facilities. The proposed selected model is used to solve the location of information inquiry platform of metro stations. The results show that among the 24 locations in Xizhimen Metro Station, 7 inquiry tables for guidance facilities can be selected. Now, the effective increment of guidance information is the greatest. The research results can provide a theoretical reference for the optimization of guidance facilities in metro station.

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    Adaptive IOA Algorithm for Coordinated Model of Signal Control and Traffic Assignment
    DUAN Li, LIU Cong-jian, FANG Zhi-lin, CHNEG Zi-wei
    2019, 19(6): 77-84. 
    Abstract ( )   PDF (469KB) ( )  

    To solve the coordinated model of signal control and traffic assignment, the IOA (Iterative Optimization and Assignment) algorithm solves the sub- problem separately, and iterates to convergence. It converges quickly, but the solution quality needs to be improved. This paper proposes an adaptive IOA (Adaptive Iterative Optimization and Assignment, AIOA) algorithm to improve the solution quality while maintaining the calculation speed. Firstly, the difference value of link flow in the iterative process is added as an adaptive correction term to the input parameters of the signal control model, which increases the variation of the solution. It can not only accelerate the convergence speed but break through the limitation of the IOA search range. Secondly, the local search strategy of the golden section method is adaptively used according to the trend of the objective function to avoid the solution become bad. Simulation results show that the AIOA algorithm reduces the gap between the IOA algorithm and the global optimal solution by 50.8%, while the time cost is 10% lower, and only 1% of the genetic algorithm. The AIOA algorithm can obtain a satisfactory solution in a short time, and can be used in large road networks.

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    Exploring Fleet Size of Shared Autonomous Vehicles in Future City: A Case Study in Shanghai
    YAO Xiao-rui1, 2,WANG Guan1, YANG Chao1, 3
    2019, 19(6): 85-91. 
    Abstract ( )   PDF (451KB) ( )  

    The development of autonomous driving technology has made it possible to replace traditional manned vehicles with Shared Autonomous Vehicles(SAV) in the future. The SAV' s fleet size problem is studied in the case of using SAV to meet all motorized travel demands of residents. The cell phone signaling data of 3 million users in Shanghai was used, and the motorized travel demands were extracted from it. The impact of actual road conditions in Shanghai was considered. A graph theory model based on the vehicle-sharing network was established to convert the minimum fleet size problem into the minimum path cover problem of directed acyclic graphs, which was solved by the Hopcroft-Karp algorithm. 128 000 SAVs are needed to meet the motorized travel demands of 3 million cell phone users. The impact of maximum scheduling time limit, service area limitation and traffic congestion on fleet size are also studied. Providing a reference for determining the fleet size of SAVs and corresponding infrastructure planning at the city level after the popularization of the autopilot technology.

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    Systems Engineering Theory and Methods
    An Integrated Bus Holding and Limited-boarding Strategy Considering Passengers' Perception
    CHENWei-ya, WEI Xiao-fan, LI Yao-tong, ZHANG Heng-peng
    2019, 19(6): 92-98. 
    Abstract ( )   PDF (437KB) ( )  

    To reduce bus bunching and improve the perceived satisfaction of passengers, this work proposes an integrated bus holding and limited- boarding strategy based on predictive control method, which considers the dynamic perception of passengers. Based on a predictive control optimization model minimizing the perceived waiting time of the total passengers on the bus line, a differential evolution algorithm is used to obtain the optimal holding time and boarding limits on target stop. Four control policies are studied in a cellular automata simulation model to compare the control effects: holding strategy(H), limited boarding strategy(LB), holding and limitedboarding strategy without considering passengers' perception(HLB); holding and limited- boarding strategy considering passengers' perception(HLBP). Five kinds of bus operation scenes are designed to compare the adaptability of HLB and HLBP to the fluctuation of passenger arrival rate and alighting ratio. The results show HLBP outperforms other control schemes in terms of reduction to perceived waiting time, and has better adaptability to the fluctuation of arrival rate and alighting ratio of passengers.

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    Optimization of Real-time Customized Shuttle Bus Lines Based on Reliability Shortest Path
    SHEN Chan, CUI Hong-jun
    2019, 19(6): 99-104. 
    Abstract ( )   PDF (361KB) ( )  

    In order to optimize customized bus routes in real time, a route optimization method based on reliability shortest path is proposed. The aim is to efficiently and quickly deliver passengers to their destinations in complex traffic environments. Firstly, we describe the reliability shortest path and establish the reliability spacetime network. Then, the algorithm steps for solving the shortest path of reliability are given. Next, we construct the objective function with the minimum total cost of passengers and customized shuttle bus operators which solved by Tabu search algorithm. Finally, we take a city customized shuttle bus network as an example to verify the model. The results show that compared with the shortest path scheme, the proposed method is similar to the actual operation. It can greatly improve the reliability of bus under the condition of rush-hour traffic jams and enhance the level of bus service.

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    Flexible Bus Route Optimization Scheduling Model for Multi-target Stations
    SUN Ji-yang, HUANG Jian-ling, CHEN Yan-yan, WEI Pan-yi, JIA Jian-lin
    2019, 19(6): 105-111. 
    Abstract ( )   PDF (358KB) ( )  

    Based on the known demand of passengers, vehicles capacity and travel time between stations, a flexible bus route optimization scheduling model for multi-target stations is proposed, whose target is minimizing the sum of the vehicle running time and the passenger travel time. The gravity model is utilized for vehicle routing initialization, and the heuristic algorithm is applied for the vehicle routing optimization. According to the results of simulation cases, when there are large differences and uncertainties in the distribution of passenger demand, the demand of all passengers can still be satisfied, and the total travel time of bus is relatively stable, and the path optimization calculation of the system takes less time, which verify the practicability of the model and the algorithm. The research results show that the flexible bus route optimization scheduling model for multi-objective stations can meet the passenger demand to the greatest extent and achieve the maximum balance between enterprise cost, passenger time cost and demand response, which is of great significance in the actual traffic.

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    Modelization and Resolution of Ride-sharing Problem with Spatiotemporal Thermo
    GUO Yu-han, YU Jun-yu
    2019, 19(6): 112-122. 
    Abstract ( )   PDF (738KB) ( )  

    Taking the influence of spatiotemporal thermo on driver's profit into consideration in ride- sharing problem, a mathematical model is constructed to optimize the profit of drivers and the percentage of shared routes, and a multi-process evolutionary heuristic is proposed to solve the problem. Based on historical data, the approach first uses cubic spline interpolation method and compound Simpson quadrature method to predict the spatiotemporal thermo, so as to estimate driver's profit in ride- sharing. In the evolutionary algorithm, different crossover strategies are adaptively and dynamically selected according to individual differences to balance automatically the intensity and the diversity of the search process. The experimental results show that, compared with the Hungarian optimization algorithm, this algorithm can obtain high quality solutions with short computing time when the same utility matrix is used as input, and has good performance in dealing with large-scale instances, therefore can efficiently solve ride-sharing problem.

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    Taxi Sharing Route Planning Based on Improved Genetic Algorithm
    ZHANG Xi-jun, ZHANG Qi-rui, ZHANG Li-juan,WANG Chen-hui
    2019, 19(6): 123-128. 
    Abstract ( )   PDF (439KB) ( )  

    Common taxis working mode is inefficiently and increases congestion in the city. Aiming at the current problem of low taxi carrying rate and unreasonable route planning in Lanzhou, this paper designs a taxi sharing route planning model based on improved genetic algorithm, which takes the maximum carrying rate and the shortest driving distance as the objective function and considers the problems of taxi capacity limitation, the driving distance limitation and the number of people getting on and off. The model was solved by means of championship selection strategy, station fragments cross design and station supervised mutation. Finally, the taxi data of Lanzhou were simulated. The research result was shown that the designed taxi sharing route planning model and algorithm could quickly obtain the optimized paths of the multiple taxis, and the planning routes of multiple taxis were meet the requirements of the highest carrying rate and the shortest distance at the same time.

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    Path Selection Behavior Based on Stable Matching
    JIA Fu-qiang, LI Yin-zhen, YANG Xin-feng, MAChang-xi
    2019, 19(6): 129-134. 
    Abstract ( )   PDF (327KB) ( )  

    To better investigate traveler path selection behaviors by the two- sided matching theory, a modified bipartite graph embedded with traveler and path is proposed. By using the proposed method, it is found that there is a Nash equilibrium within the stable matching thus the derived Nash equilibrium can be further used to analyze travel selection behaviors. Moreover, a multi-objective optimization model considering both the traveler's income and route influence is established. The multi- objective optimization model includes two assignment models that one is considering the influence of flow and capacity while the another is not. This established problem is solved by the Hungarian algorithm. The simulation results of the numerical example show that the path selection behaviors are satisfied the user equilibrium principle in both conditions, i.e., with and without considering the flow and capacity. Thus, it is efficient to establish the corresponding traffic assignment model.

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    Commute Time Pattern of Relocated Residents in City Based on Classification Decision Tree
    WU Jing-xian, YANG Min, HAN Yin
    2019, 19(6): 135-140. 
    Abstract ( )   PDF (403KB) ( )  

    Focusing on the long-distance and long-time commute of relocated residents, this study analyzed the impact of factors including personal and household characteristics, relocation attribute, built environment and commute attribute on commute time of relocated commuters by using multivariate linear regression model. After the identification of significant variables and the discretized value by linear regression model and Logistic regression model, a classification decision tree was developed to interpret the commute time pattern of relocated commuters in different scenarios by using the C4.5 algorithm. The result indicates that same zone of job-housing, departure time, house type, job-housing distance, commute mode, and accessibility of community to arterials are detrimental factors of commute time compared to personal and household characteristics, reflecting that policies that optimize the built environment in micro level contribute more in improving commute efficiency for relocated residents.

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    Control Method for Passenger Inflow Control with Coordination on Urban Rail Transit Line in Peak Hours
    LI Deng-hui, PENG Qi-yuan, LU Gong-yuan,WANG Kun, WU Zheng-yang
    2019, 19(6): 141-147. 
    Abstract ( )   PDF (361KB) ( )  

    The executability of the passenger flow control strategies and the coordination among the strategies need to be simultaneously taken into account in the passenger flow control on an urban rail transit line. In this paper, the reasonable control time intervals are firstly determined by Fisher optimal division method. Then this paper proposes a linear programming model for passenger flow collaborative control, which aims at minimizing the total passenger waiting time and maximizing the passenger person- kilometers. Based on the data of AFC of Chengdu Metro Line 2, this paper makes two group of experiments of comparative analysis, including the collaborative and non- collaborative control strategies; and the collaborative control strategies under different control time interval division strategies. In the experiments: the total passenger waiting time decreases by 56.7% when the passenger person-kilometers decreases by about 1.0%; the collaborative control strategy from the control time intervals based on Fisher optimal division method is optimal in the total passenger waiting time and has a high executability.

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    Integrated Model Method for Multiple-unit EMU Operation and Maintenance Based on Pareto Frontier Analysis
    FU Jian-jun, ZHANG Xing-chen,WANG Zhi-mei
    2019, 19(6): 148-155. 
    Abstract ( )   PDF (369KB) ( )  

    The utilization and maintenance of EMUs is an important process in railway transportation production, accounting for a large proportion of costs. In order to match the passenger flow demand, it is possible to realize the combination and decomposition of the EMU trains in some hub stations in the future. Under this assumption, we fully consider the consistency of combined motor trains, the connection conditions for reconnection and decomposition in different operation lines, primary and secondary maintenance costs. Based on the double target, the minimum sum of the EMU connection time costs and vehicle return empty costs, we construct an integrated model method for the EMUs' application and maintenance based on variable grouping conditions. The improved non- dominated sorting genetic algorithm is used to solve the problem and analyzed by Pareto frontier and we found that it is difficult to achieve optimality at the same time. The calculation results of the model reflect the combination and decomposition process of the EMU. At the same time, it also further analyzed the changes in the number of EMUs used in the case of normalization of the EMU type or the unrestricted maintenance position of the EMU, reflecting the impact of relevant operating parameters on the conclusion.

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    Train Flow Diagram Generation Based on State Matrix in Railway Junction
    WANG Bao-shan, LUO Hui, LIU Hai-dong
    2019, 19(6): 156-162. 
    Abstract ( )   PDF (473KB) ( )  

    Aiming at the characteristics of the complex structure of railway junction and the difficult drawing process of train flow diagram, this paper study on the automatic generation of train flow diagram for railway junction. There are more connections to railway junction station. Train flow lines are difficult to settle in the station area. State matrix is introduced and state variables are used to record the distribution of the train flow lines in the station area. Train type is the primary sort and train flow is generated in the order of path length from long to short. Annotation of train flow is achieved with indicated lines. Software system is developed to implement the algorithms. Train flow diagram is automatic generated with annotation based on the junction net, train flow matrix, the station layout and their links. The example shows the effectiveness and feasibility of the algorithms and software.

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    Classification Method of Traffic Impact Grade of Urban Traffic Emergency Based on Percentile Speed
    HE Ya-qin, RONG Yu-lun, LIU Zu-peng
    2019, 19(6): 163-167. 
    Abstract ( )   PDF (322KB) ( )  

    Urban intersection is a concentrated area for emergencies. It is easy to cause regional congestion after emergencies occur. it is difficult for the traffic management department to intuitively take corresponding emergency measures. Establishing a quantitative method to evaluate the grade of traffic impact of emergencies can provide important reference value for traffic management department to make emergency measures at corresponding levels. Based on the principle of water wave, this paper uses traffic impact coefficient to build the threshold model of traffic impact grade by fusing percentile speed. The relationship between speed and location is obtained by using sample data modeling. The threshold of traffic impact grade can be obtained through integrated analysis of relationship curve of speed and location and flow rate of intersection in each direction. Finally, the model is verified using the case in literature and the result shows the classification of traffic impact is in consistent with the actual description of the accident scene. Research results can provide decision- making basis for traffic emergency management departments to respond quickly and take reasonable and effective emergency measures.

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    Decentralized Lane-changing and Speed Guidance Methods for Urban Expressway and its Adjacent Intersection
    PANG Ming-bao, AN Shao-yi
    2019, 19(6): 168-175. 
    Abstract ( )   PDF (512KB) ( )  

    The mainline decentralized lane- changing and speed- guiding adaptive control methods for urban expressway and its adjacent intersection with cooperative vehicle infrastructure system (CVIS) is studied. Under high saturation, a mainline decentralized lane- changing adaptive control method is proposed and used for the subsystem of on-ramp and its adjacent intersection, where the lane-changing rules are obtained according to the densities of different lanes in merging area and the phases and their sequence are obtained in order to maximize the mainline flow. A mainline speed guidance adaptive control method is proposed and used for the subsystem of offramp and its adjacent intersection under overfull queue situation, where the speed guidance strategy is obtained according to the destinations of vehicles upstream of mainline and the priority of the correlated phase of off-ramp is obtained in order to match the demand and capacity of the off- ramp. The effectiveness is validated through simulation experiments by using cellular automaton model (CAM). The results indicate that compared with noncoordinated control, traditionally coordinated control and adaptive control for intersection with CVIS, the flow of the area of the methods mentioned is increased by 17.38%, 5.52%, 10.06%, and the total time spend(TTS) is reduced by 35.86%, 26.21% and 17.39%, respectively.

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    Location of Terminal Distribution Station of Urban Cold Chain Logistics Considering Travel Time Reliability
    YIN Xiao-qing, MO Yu-di, DONG Chen-chen, LIN Yun
    2019, 19(6): 176-183. 
    Abstract ( )   PDF (712KB) ( )  

    The timeliness of“last mile”distribution of urban cold chain logistics has a great impact on the cargo damage rate and customer satisfaction. Therefore, it is of great significance to improve the timeliness of terminal distribution of urban cold chain logistics. However, the harsh traffic conditions and the high dispersion of customers in the city often lead to difficulties in improving the timeliness of terminal distribution. Therefore, from the perspective of travel time reliability, a location method for the terminal distribution station of urban cold chain logistics based on complex network theory is proposed. First, the complex network theory is employed to construct the terminal logistics demand point network of urban cold chain logistics, which fully considers the travel time reliability. Second, the community detection method is used to cluster the terminal customers in stages. Third, degree centrality and strength centrality are used to make location decision. Fourth, the distribution timeliness of the location scheme is evaluated. Through the simulation of the terminal logistics demand point network, and the location decision of the network model, it shows that the method is accurate and effective, and can fully guarantee the timeliness of terminal distribution of urban cold chain logistics.

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    Optimization Model of Online Catering Order Delivery under Mixed Order Mode
    ZENG Qing-cheng, MAJia-hui, ZHANG Xiao-lin
    2019, 19(6): 184-190. 
    Abstract ( )   PDF (452KB) ( )  

    In order to solve the problem of unreasonable scheduling and resource waste caused by the surge and uneven distribution of online catering orders, this paper puts forward an order mode combining advance and dynamic real-time ordering, and studies the order delivery optimization under this mode. Considering the dynamic VRP and multi-trip VRP attributes of online catering order delivery optimization, an integer programming model with soft time windows was developed to minimize the total delivery cost. To solve the model, a hybrid heuristic algorithm based on insertion algorithm and 2-opt local search was designed. Numerical experiments were provided to analyze the influence of factors including the proportion of advance ordering customers and the length of advance time. The results show that any factor' s increase can reduce the delivery cost. However, when two factors increase at the same time, the system becomes saturated and the delivery costs do not rise but fall. Therefore, it is necessary to adjust measures to make the customer order status match the system' s distribution capability.

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    Robust Location Model and Algorithms for Over-seas Warehouse in Cross-border Supply Chain Network
    YAN Chen-yi,WANG Xi-fu, YUN Li-fen
    2019, 19(6): 191-198. 
    Abstract ( )   PDF (387KB) ( )  

    Under the new economic form, the global political and economic situation is changing rapidly, and a variety of human and natural factors lead to the increasingly severe living environment faced by the commercial supply chain. As a typical complex network with great uncertainties in timeliness and operating environment, the research of cross-border supply chain network robustness has certain theoretical significance and practical application scenarios. Firstly, this paper clarifies the connotation of supply chain robustness and cross- border supply chain network, analyses the robustness of cross-border supply chain networks. Secondly, based on the idea of minimum and maximum regret value, this paper constructs a robust location model for overseas warehouses, and solves the model by using scenario relaxation algorithm. The results show that the constructed model and algorithm are suitable for cross-border supply chain network scenarios.

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    An Optimization of Pure Electric Vehicle Routing Problem on Half-open Multi-distribution Center
    MABing-shan, HU Da-wei, CHEN Xi-qiong, HU Hui
    2019, 19(6): 199-205. 
    Abstract ( )   PDF (441KB) ( )  

    With the rapid development of e- commerce, more and more logistics enterprises adopt multidistribution center model to optimize vehicle distribution routes. The pure electric vehicle makes the traditional fuel distribution vehicles gradually replaced to improve the ecological environment. Combining the characteristics of multi-distribution center joint service mode and the driving characteristics of pure electric logistics vehicles, a half-open multi-distribution center pure electric vehicle routing problem with time windows is modeled, and an ant colony algorithm is designed to solve it. The comparative analysis of several instances shows that half-open multidistribution center's joint service can rationally utilize relevant logistics resources, improve vehicle routing and reduce logistics costs, but it needs to be joint with appropriate number and location of distribution centers to achieve the best cost- saving effect. Meanwhile it provides more potential charging points with lower price than single distribution center, so considering supplying electricity from distribution center can save logistics cost to some extent.

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    Optimization of Quotas and Yard Crane Allocation in Pick-up Truck Appointment
    LI Na, BIAN Zhan, XU Qi, JIN Zhi-hong
    2019, 19(6): 206-214. 
    Abstract ( )   PDF (791KB) ( )  

    In pick- up truck appointment at container terminal, combined optimization of yard crane allocation and quotas is the key to reduce truck waiting time and improve the efficiency of resource utility. Under the real features of pick-up operation, a bi-objective integer programming model is set up. Based on non-dominated sorting genetic algorithm, a fast and efficient algorithm is developed. When the requirement of terminal is lower, dynamic random should be adopted to allocate yard cranes. If that is higher, combination of dynamic ratio and minimum allocation should be adopted. Numerical experiments of different sizes are proposed based a container terminal in China. The experiments prove the effective of the model and the algorithm, which could generate high-quality and multiple pareto front solutions. The optimized matching of yard crane resource and operation requirement from trucks is achieved. It provides decision support for terminal operators in balancing resource input and truck waiting time.

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    Multi-port Berth Co-scheduling with Speed Optimization
    YANG Jie, LI Ting, BAI Peng-rui
    2019, 19(6): 215-222. 
    Abstract ( )   PDF (436KB) ( )  

    The container transport has been playing an important role in the global trading system, and it also faces many challenges and opportunities brought about by globalization. In this paper, the multi-port BAP which is extended from the classical single-port BAP is solved. We establish a multi-port berth co-scheduling model with the aim of minimizing the total cost. Considering the impact of vessel' s sailing speed on its arrival time at a port and fuel consumption, the speeds of vessels are formulated as decision variables. We introduce an improved genetic algorithm to solve the mathematical model. Experiments with artificial test instances are performed. The results indicate that speed optimization can help reducing the total cost of the operation, and obtaining far better economic and environmental benefits.

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    Coordinated Optimization Problem of Slot Planning and Shipment Sequencing
    LIU Zhi-xiong, YAN Jia-lan, ZHANG Yu
    2019, 19(6): 223-230. 
    Abstract ( )   PDF (501KB) ( )  

    Aiming at the coordinated optimization problem of slot planning and shipment sequencing, a mathematical model is established with the objective of minimizing the sum number of the reloading operations of the yard and the ship. At the same time, various constraints of the yard and the ship are considered comprehensively. By proposing a hybrid evolutionary strategy algorithm (HES), the two-dimensional real coding and decoding method based on moment balance and stowing column by column are designed to solve the problem. Furthermore, the local search strategy is adopted to improve the algorithm. The calculation results show that the HES algorithm can solve the coordinated optimization problem of different scales. At the same time, by comparing with the traditional evolutionary strategy algorithm (ES), the particle swarm optimization (PSO), and the heuristic algorithm based on actual shipping rules (HA-MBSCC), the superiority of the HES algorithm is further verified.

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    Cases Analysis
    Community Structure of World Container Shipping Network
    GE Jia-wei,WANG Xue-feng,WAN Zheng, HUANG Tian-rong
    2019, 19(6): 231-236. 
    Abstract ( )   PDF (404KB) ( )  

    Based on the complex network theory, this paper discusses the structural characteristics of the world container shipping network and provides a new perspective on the division of maritime regions. The up- to- date data verified the small world and scale- free characteristics of the shipping network. According to the concept of modularity and its resolution, the network is further subdivided into three major maritime regions and eight blocks. The main research findings are: Network distribution is in accordance with the power law distribution (power: - 8.96); Layout of maritime blocks have obvious spatial characteristics restricted by natural geography like straits and canals; Maritime blocks are different in vitality which can be measured by the change of average weighted route density; Maritime blocks also have small worlds and scale-free characteristics in spite of the block scale; The clustering coefficient of regional hub ports generally approaches 0.2, providing a basis for identifying large transit hub ports.

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    Bus Route Choice Model Considering Congestion Information Provided by Smartphone
    SONG Cui-ying, GUANWei, MAJi-hui
    2019, 19(6): 237-242. 
    Abstract ( )   PDF (370KB) ( )  

    In transit network, the travel information shown by smartphone can provide effective help for bus passengers. The paper simulates the process of passengers' choosing routes based on the congestion information from smartphone. Two route choice models referring to the departure and transfer route are constructed including the seat allocation process in the bus and the queuing process in the platform. By simulation calculation, the results of in- vehicle congestion are analyzed between the condition with congestion information and the condition without, which uncovers the principles of passengers' choosing routes by receiving the congestion information from smartphone. The results show that the congestion information provided by smartphone can decrease the onboard congestion condition and help to improve the in-vehicle environment.

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    Analysis of Effects of Rainfall on Origin-destinationbased Travel Time Reliability
    ZHANG Qi, CHEN Hong, LIU Zhi-zhen, ZHANG Min
    2019, 19(6): 243-249. 
    Abstract ( )   PDF (396KB) ( )  

    With the purpose of investigating the effects of various rainfalls on the origin-destination(OD)-based travel time reliability (TTR) in detail, Gaussian mixture models of OD-based travel time were constructed based on three-year travel time data of ten OD pairs in Boston, USA, shared by Uber movement, and the hourly historical weather provided by WeatherUnderground website. And the model parameters, K -value and percentile-value were solved by expectation-maximum algorithm, the P-value (greater than 0.500 0) after K-S test and bisection method, respectively. Additionally, buffer index variation ratio (BIVR) is proposed for quantitative analysis. The results show that: rain can reduce the overall ODTTR, and the reduction effect increases with the rainfall increase, but the gaps are unobvious; Despite lower probability, ODTTR may be improved when rain as a secondary factor; Light rain can be regarded as normal weather; The ODTTR of rainy days is significantly lower than that of normal weather, so residents should reserve more time for travel in rainy days (except light rain).

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