2017 No. 3

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2017, 35(3)
Abstract(240) PDF(2)
Abstract:
Overview
A Review of 2017 Transportation Research Board 96th Annual Meeting with the Focuses and Areas of Pedestrian Traffic and Intelligent Transportation
2017, 35(3): 1-10. doi: 10.3963/j.issn.1674-4861.2017.03.001
Abstract(416) PDF(5)
Abstract:
The 2017 Transportation Research Board 96th Annual Meeting (TRB2017) is introduced and reviewed with the focuses of new progresses and trends of studies on pedestrian traffic and intelligent transportation.The executive framework of TRB, organization of TRB annual meeting, as well as categorization of research fields in the annual meeting are introduced.For a research area of pedestrian traffic, the works of 6 relevant TRB (sub-) standing committees, including but not limited to "Traffic Flow Theory and Characteristics", "Emergency Evacuations", and "Pedestrians", etc., are summarized.Studies on pedestrian traffic are systematically reviewed and categorized into 4 topics, including crowd dynamics, emergency evacuations, road pedestrian traffics, and passenger services and safety.For a research area of intelligent transportation, the works of 3 relevant TRB standing committees, including "Intelligent Transportation Systems", "The Role of Automated and Connected Vehicles", and "Vehicle-highway Automation", are summarized.Studies on intelligent transportation are systematically reviewed and categorized into 2 topics, including effects of intelligent transportation on driving safety and effects of intelligent vehicle infrastructure cooperative systems (IVICS) on transportation efficiency and environment.
Transportation Safety
A Study on a Guide System of Automated Cone Placement Vehicles for Isolation of Traffic Accident Scenes on Freeways
2017, 35(3): 11-18. doi: 10.3963/j.issn.1674-4861.2017.03.002
Abstract(422) PDF(2)
Abstract:
The effectiveness of automated cone placement and retrieval is mainly depended on drivers' experience when they operate vehicles on freeways.Therefore, it is important to implement an intelligent guidance for automated cone placement vehicles to achieve optimal cone placement.The requirements for intelligent guidance are analyzed, and rules of a guide system are designed according to the specification of isolation for accident scenes on freeways.A control strategy of timing for cone placement is developed based on the feedback of vehicles' speed.A case study is conducted based on a developed platform of automated cone placement vehicles.The results show that when the intelligent guidance system is working, a cone placement vehicle operating with the speed of 5 km/h and 10 km/h, the average position error of cone placement is reduced by 72.46 % and 72.90%, respectively.The accumulative position error is reduced by 72.62% and 73.15%, respectively.The results show that the proposed guidance system can improve the intelligence and informatization of automated cone placement vehicles.This study can provide references for design and implementation of cone placement and retrieval vehicles in the future.
A Study on Weather Alert for UAVs Based on Weather Radar Mosaic
LI Bo, TANG Xinmin, TIAN Feng, XU Feng
2017, 35(3): 19-25,33. doi: 10.3963/j.issn.1674-4861.2017.03.003
Abstract(406) PDF(3)
Abstract:
A thunderstorm is an important weather factor to operation safety of unmanned aerial vehicles (UAVs).To obtain real-time precipitation data and give the alert information is of great significance for the safe operation of UAVs.Based on registration and projection transformation, a method to calibrate weather radar mosaic is proposed.Furthermore, a dynamic Z-R fitting scheme for radar quantitative precipitation estimation (QPE) is developed.In the end, a method for quantifying threat degrees of precipitation to UAVs is presented to give weather alert accordingly.A case study shows that the proposed methods can be implemented to improve the precision of radar mosaic and the accuracy of radar QPE.Moreover, the dynamic fitting of Z-R is proved to be more accurate than the fixed Z-R for precipitation estimation.The cumulative damage can be used as a reference for risk warning of UAVs.
Human Reliability Prediction for Ship Pilot Based on Modified CREAM
JIANG Feifei, HUANG Ming, JIANG Fucai
2017, 35(3): 26-33. doi: 10.3963/j.issn.1674-4861.2017.03.004
Abstract(439) PDF(9)
Abstract:
In order to precisely predict human reliability of ship pilots, this paper proposes a model to analyze human reliability based on cognitive reliability and error analysis method (CREAM).An improved decision-making and trial evaluation laboratory (DEMATEL) method is utilized to obtain the weights of common performance conditions (CPCs) by using triangular fuzzy numbers.Then, a fuzzy comprehensive evaluation method is introduced to evaluate the performance CPCs, which can reduce the influences of subjective assessment when considering judgments from experts.Afterwards, the relationship between situational environment index and human error probability is established for a precise prediction.Finally, the results of modified CREAM and basic CREAM is compared under both actual and predefined scenarios.The result demonstrates that the modified CREAM is more reliable and sensitive than the basic CREAM.
Transportation Information Engineering and Control
A Study on Impedance Function of City Secondary Road Based on Taxi GPS Data
2017, 35(3): 34-42. doi: 10.3963/j.issn.1674-4861.2017.03.005
Abstract(458) PDF(2)
Abstract:
Reasonable, accurate, and real-time impedance functions are prerequisites for dynamic traffic induction of urban roads, which is also a classical problem in traffic planning.At present, there are few studies on the dynamic changes of traffic capacity and impedance function of city secondary road, especially under influences of illegal parking.For massive taxi GPS data from Wuhan, a screening strategy of massive GPS data for different road scenarios and taxi operation statuses are put forward to calculate travel time.Smats portable Bluetooth and Wi-Fi scanner equipments are used to collect traffic flow.According to the working principle of the equipments, a corrective method for error data is developed, and then the correspondence between actual data of traffic flow and experimental data is obtained.At last, the changing regulation of road traffic capacity under illegal parking is introduced into BPR impedance function, and its coefficients are calibrated by actual data.The accuracy of the function is verified.Compared with the traditional BPR method, the results show that the mean error of the recalibration BPR method is reduced from 26.1 s to 6.8 s.
An Analysis on Time Coverage Rate of RFID Traffic Data
YANG Yuesi, DU Wei, NING Dan, GUO Jianhua
2017, 35(3): 43-50,58. doi: 10.3963/j.issn.1674-4861.2017.03.006
Abstract(448) PDF(2)
Abstract:
In the field of road traffic status identification, parameters on "time occupancy" based on data collected from magnetic loops have been widely used.However, such data cannot be obtained from traffic flow data collection methods based RFID technologies.Based on the analyses of RFID data characteristics, this paper proposes a novel concept of Time Coverage Rate (TCR) and its calculation method.TCRs are calculated with the consideration of 7 types of time aggregation levels.Curves of base stations' TCRs taking time aggregation levels as an independent variable are drawn according to the calculation results.Status of the base stations, the volume as well as the continuity of the traffic flow at the base stations'' location can be roughly estimated based on the trends of these curves.21 RFID base stations on arterials of Nanjing are chosen for a case study in which the proposed approach is used.The results show that the curves of the TCRs can be categorized into 3 types, including: ① Daily coverage rate is less than 100%.② Daily coverage rate is equal to 100% and time aggregation is between 1 h and 5 min, TCRs are near to 100%;③ Daily coverage rate is equal to 100% and time aggregation is between 1 h and 5 min, TCRs decrease.Each type represents a certain working condition of base stations and different characteristics of traffic flow.It can be seen that, time coverage rate has practical significance for performance evaluation of RFID base stations and analyses of traffic flow statuses.
Spatial-temporal Characteristics of a Shared Bicycle System Based on Web Crawler Data
ZHUANG Chutian, WU Ge
2017, 35(3): 51-58. doi: 10.3963/j.issn.1674-4861.2017.03.007
Abstract(482) PDF(1)
Abstract:
It is a prerequisite to optimize the operation of a shared bicycle system by collecting spatial-temporal characteristics of it.A web crawler technology is used to obtain data of stations.After that, indices like activity score (AS) are defined to measure operation of the system.In order to identify a valid cluster algorithm for computing AS, several methods are compared by using Dunn index and Davies-Bouldin index.Global and local Moran's statistics are introduced to analyze spatial-temporal characteristics of stations usage.In a case study of a shared bicycle system in Suzhou, stations are clustered into four types according to the changing regularity of AS.It is found that activity of one station has positive spatial correlation with 13 stations during rush hours in evening and 20 stations during rush hours in morning.It is speculated that average riding distance are 1.7 km and 2.2 km, respectively.Although majority of the normalized available bicycles (NABs) at peak times are spatially distributed at random, this study still finds that stations with high NAB are gathered in several different areas.Stations with low NABs are centrally located in a larger area in the city.The results also clearly reveal existing problems of coordination between stations in the system.
A Study on Communication Performance in AIS Network of Inland Rivers
WU Jianhua, GUO Junwei, LIU Wen, WU Chen
2017, 35(3): 59-67. doi: 10.3963/j.issn.1674-4861.2017.03.008
Abstract(468) PDF(4)
Abstract:
With rapid increasing of ships, the channel load of AIS system in dense navigable water areas also increses rapidly.Time slot conflict in systems, channel congestion, and anomaly communication of AIS network, which cause reduction of reliability for its application, is becoming a hidden hazard of ship navigation safety.In order to accurately and timely reflect the actual situation of communication performance in AIS network, indicators are monitored in real-time based on AIS integrated application platforms.Based on the AIS data of Wuhan section of Yangtze River, the communication performance of AIS network in this water area is evaluated using one week data from five aspects, which are network capacity, network channel load, network throughput, network utilization, and network blocking rate.The tendency and limit state of the communication performance in AIS network is studied by a simulation.The results show that the channel load rate of AIS network in Wuhan section is about 15%, while its throughput is close to 100%, and communication performance is good.If the number of ships increases when the channel load rate reaches 60.5%, communication congestion will be achieved in the AIS network, and the number of ships in 13 motion states are obtained when communication congestion occurs.The results objectively and accurately reflect the communication performance of AIS network in studied area, and can provide technical supports to monitor, manage, and control the AIS system for inland maritime authorities.
A Study on Data Cleaning for Energy Efficiency of Ships
2017, 35(3): 68-73. doi: 10.3963/j.issn.1674-4861.2017.03.009
Abstract(417) PDF(5)
Abstract:
Data cleaning for energy efficiency of ships is of great importance to develop an accurate energy efficiency modeling as well as to improve the accuracy of its calculation and analysis, which can be used to guide energy-saving navigations of ships.Fault features of the data are analyzed and recognized by threshold theory and co-relation analysis.The abnormal data of water depth, ship speed, and fuel consumption are modified by interpolation and grey relational theory.Based on this, a process for data cleaning of energy efficiency is developed.The data collected by the relevant systems on ships are chosen as a case study and cleaning results are analyzed.The results show that the mean error between the modified and measured values of water depth, ship speed, and fuel consumption is 1.58%, 2.8%, 1.5%, respectively.They are satisfactory to meet the requirements of further modeling and data mining.
A Clustering Algorithm of Wireless Sensor Networks for Intelligent Transportation
SU Hang
2017, 35(3): 74-79,106. doi: 10.3963/j.issn.1674-4861.2017.03.010
Abstract(257) PDF(2)
Abstract:
Wireless sensor networks (WSNs) are important components of intelligent transportation systems.The energy efficiency of WSNs can benefit from a suitable clustering technique.Based on Energy Efficient Clustering (INEEC) scheme, a clustering algorithm of WSNs is studied in this paper.Operating time is divided into several rounds.Cluster head (CH) is determined in each round to balance energy consumption of CH.During a selection phase of CH, each node chooses a random number and computes the threshold value of the random number by residual energy and the average of the regional energy of all sensors in each cluster.If the random number is less than the threshold value, the node becomes a CH for the current round.Each CH broadcasts a joining request message to the rest of nodes.If a non-CH node receives many joining request messages, the node decides to join the closest cluster accordingly.Those non-CH nodes that do not receive a joining request message are considered as isolated nodes.In order to improve the energy efficiency of an isolated node, INEEC scheme determines its transmission model.Compared with the HEED and LEACH algorithms, the simulation results show that INEEC scheme has better performance in reducing energy consumption which means this scheme has the least isolated nodes, the minimum transmission delay, and a more uniform CH distribution.In detail, the network lifetime increases nearly 23.5% compared with the HEED algorithm.Key problems in the application of the INEEC algorithm, such as high energy consumption, low energy efficiency and network lifetime, are well solved in this study.
An Allocation Method and a Checking System for of Highway Tolls: A Case Study in Hubei Province
WANG Sanjun, YU Qian, ZHOU Wenwei, YANG Houxin
2017, 35(3): 80-89. doi: 10.3963/j.issn.1674-4861.2017.03.011
Abstract(311) PDF(2)
Abstract:
Tolling highway is one of the major contributions to promoting economic and social development in Hubei province, with the purpose to effectively managing highway tolling systems, a method to allocate tolls is proposed, and a system for checking accuracy of allocation is developed as well.An AD-DFS algorithm is studied to identify dispute paths of vehicles based on the current situation of infrastructure construction and operation of Highways in Hubei province.Under the condition of limited flag stations and restriction of the length of paths, the AD-DFS algorithm captured vehicles'' license plates at first.Then with these positioning data of vehicles, the algorithm identifies possible paths of vehicles as their dispute paths.An algorithm for identifying vehicles'' allocation methods from identified dispute paths is also developed, which is still effective even under a circumstance of abnormal data recorded in flag-stations.For different types of vehicles and allocation methods, an adaptive method is proposed to precisely and fairly allocate the tolls to corresponding management units.Based on the aforementioned methods, a system for checking them is also developed in Hubei province, which is the first province-level platform in China that offers the function of checking the allocation of highway tolls.After being implemented in 64 highways, 351 toll stations and 104 management units in Hubei province, the results indicate that the system has high efficiency, and receives positive feedbacks.It can offer management and decision supports with multi-level and multi-dimensional data visualization analyses.
Transportation Planning and Management
A Simulation-based Performance Evaluation on Transient-value-based Route Planning Strategy in Urban Road Networks
XU Guangning, WANG Yinhai, ZENG Ziqiang, AN Shi
2017, 35(3): 90-97. doi: 10.3963/j.issn.1674-4861.2017.03.012
Abstract(319) PDF(4)
Abstract:
Traditional strategies of dynamic route planning can be divided into Transient-value-based Shortest-Path-Finding (T-SPF) and Average-value-based Shortest-Path-Finding (A-SPF) in term of processing for real-time traffic conditions.It is significant for traffic management departments to know how to balance individual benefits and long-term impacts of these strategies.To this end, a series of situations based on actual road networks are simulated.Vissim Car2X module and customized programs are applied to achieve dynamic steering during the simulations.The results show that the performances of T-SPF and A-SPF under different levels of market share have their own problems.When the market share is higher than 15%, the T-SPF strategy may cause an oscillatory state in traffic capacity of urban road networks.The A-SPF strategy can achieve stable performance in average delay and traffic throughput of road networks under the same conditions.However, it shows poor performance in individual benefit.Suggestions for solving these problems are coordination of a new route planning strategy, and enhancement of an adaptive signal control policy.
A Study on Waterway Freight Impedance and Distribution Models on Yangtze River Based on Data of Ship AIS and Visa
2017, 35(3): 98-106. doi: 10.3963/j.issn.1674-4861.2017.03.013
Abstract(345) PDF(1)
Abstract:
This study aims to figure out dynamic and complex impacts of various sections of Yangtze River on waterway freight transportation.Based on AIS and residence time of ships at the Three-Gorges Dam, a freight impedance model considering ship course, waterway segment and time is developed.Meanwhile, a time impedance matrix among important ports of the Yangtze River in different months is obtained using Matlab.Taking data of ship visa in October 2010 as a case study, the parameters of two types of gravity distribution models based on distance impedance matrix and time impedance matrix are calibrate respectively.Then corresponding models of distribution of freight transportation are established.With these models, the distribution in October 2012 is predicted.A Trip Length Distribution (TLD) method is applied to check the four predicted distributions with the actual distribution in October 2012.The results show that the Coincidence Ratios (CR) values got from the inverse power function and the exponential function based on the time impedance are 0.83 and 0.86 respectively;which based on the distance impedance are 0.81 and 0.82 respectively.This study indicates that the gravity distribution model based on time impedance has a better predication performance of inland freight transportation of the Yangtze River.
Behavior Pattern Mining of Inland Vessels Based on Trajectories
ZHU Jiao, LIU Jingxian, CHEN Xiao, LI Huanhuan
2017, 35(3): 107-116,132. doi: 10.3963/j.issn.1674-4861.2017.03.014
Abstract(450) PDF(9)
Abstract:
In view of complex situations of marine traffic safety, it is of great significance to investigate AIS data mining methods for useful traffic information.On basis of behavior patterns of inland vessels, a four-dimensional state-space model including temporal and spatial locations, speed, and course is proposed to describe behavior patterns of vessels.Considering high time complexity of extracting similar ship trajectories in the state space model, an incremental DBSCAN algorithm is thus introduced for effective calculations of different behavior patterns of vessels.Statistical methods such as kernel density estimation are further applied to derive vessel behavior characteristics under different modes, and spatial-temporal distributions of microscopic characteristics (i.e.vessel speed, heading angle, and position).Six different kinds of behavior patterns are analyzed through a case study in bifurcation waterways of Hanjiang River in Wuhan, China.Static information (types and sizes of ships), spatial distribution characteristics (trajectories, speeds, and heading angles), and arrival patterns of vessels are successfully extracted.The model can be helpful to improve supervision efficiency of maritime traffic safety.
A Stochastic Optimization Model for Aircraft Routing Based on Propagated Delay
ZHOU Tan, GAO Qiang, LI Weiwen
2017, 35(3): 117-123. doi: 10.3963/j.issn.1674-4861.2017.03.015
Abstract(289) PDF(2)
Abstract:
In order to provide an effective method to control flight delay and study the influences of independent delay, an algorithm of independent delay and propagation delay is proposed.Based on the distribution of independent delays, a stochastic optimization model of aircraft routing is developed.During computation, the stochastic model is transformed into a deterministic model to reduce the difficulty in solving process.The model is verified by operation data from a large domestic airline company.The results indicate that this algorithm can reduce propagated delay by 28%, while the cost is reduced by 17.37%.It is shown that the stochastic optimization model based on delay analysis can improve the robustness of flight schedule.
A Comprehensive Evaluation System of Vessel Congestion in the Three Gorges Dam Area Based on the Cloud Model
XU Sheng, XU Zhouhua, LIU Yi
2017, 35(3): 124-132. doi: 10.3963/j.issn.1674-4861.2017.03.016
Abstract(258) PDF(1)
Abstract:
A comprehensive evaluation system of vessel congestion in the Three Gorges Dam area is proposed in order to effectively and quantitatively evaluates the congestion degree of ships passing the Three Gorges Dam.The entropy method is improved and applied to determine the index weights of vessel congestion evaluation.The method consists of subjective weights by expert surveys and objective weights through statistical analysis of actual data.Therefore, limits of subjectivity and insufficiency of data can be effectively overcome.The ratio between the subjective and objective weight is found as 0.624∶0.376.In the presence of deterministic and uncertain characteristics of the evaluation indices, an improved cloud model is developed.The eigenvalue parameters are replaced by normal elements, on basis of which the cloud correlations between matter elements and a standard cloud matter model are computed.The proposed model is applied to evaluate the degree of vessel congestion in the Three Gorges Dam area for the year 2015.The evaluation degree is known as [0.126, 0.221, 0.172, 0.325, 0.156] and the congestion degree is 4.The presented findings are generally consistent with the actual situations.

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