基于导航数据的旅游景区交通网络格局与空间结构优化——以江西省A级旅游景区为例

文章运用集聚度、连结度与可达性等指标,利用导航系统获取路网信息,探讨了江西省A级旅游景区的分布格局、交通网络及其可达性的特点与问题。研究发现:江西A级旅游景区呈“小集聚、大分散”的分布格局;交通网络的回路性较差、连接性较好、连通性一般,运输压力大;可达性整体较差,主因是高级别旅游景区的通行时间偏长;可达性呈现以南昌为高地的中心向外围骤降态势。据此提出修建旅游专用道构成环形线路,美化沿途,分流交通;丰富旅游景区活动项目以延长游客停留时间;发展清洁公共交通;重视高铁与旅游通道对接,提高省际边界的路网等级和密度等优化策略。

交通运输保障是打赢现代高技术战争的基石——访国家交通战备办公室主任、总后军交运输部部长王福臣少将(中)

随着科技的进步、政治形势的发展,战争形态、作战样式和我国的经济建设局面均发生了根本性的变化。面对错综复杂的军事与经济态势,如何使我国的交通战备工作适应发展的需要,如何应对新军事变革对其提出的要求和挑战?带着以上问题,本刊记者专程采访了国家交通战备办公室主任、总后军交运输部部长王福臣少将,并将采访手记分三期陆续刊登。本期刊登的是此次采访的(中)篇。

On the critical conditions of traffic jams

Traffic wave theory is used to study the critical conditions for traffic jams according to their features. First, the characteristics of traffic wave propagation is analyzed for the simple signal-controlled lane and the critical conditions for oversaturation is established. Then, the basic road is decomposed into a series of one-way links according to its topological characteristics. Based on the decomposition, traffic wave propagation under complex conditions is studied. Three complicated factors are considered to establish the corresponding critical conditions of jam formation, namely, dynamic and insufficient split, channelized section spillover and endogenous traffic flow. The results show that road geometric features, traffic demand structures and signal settings influence the formation and propagation of traffic congestion. These findings can serve as a theoretical basis for future network jam control.

绿色发展在五大发展理念中的作用和地位以及我国绿色发展实践

党的十八届五中全会明确提出了＂创新、协调、绿色、开放、共享＂五大发展理念。其中,绿色发展理念最为瞩目,其阐明了发展经济与保护生态的关系。当前保护环境与经济发展之间的矛盾日益突出,因此,走绿色发展之路日益成为转变我国经济发展方式、化解经济发展矛盾的内在要求和必然选择。一、绿色发展理念的提出（一）绿色发展理念提出的依据1.理论依据。绿色发展理念的理论依据是马克思主义的自然观,

Calculation connectivity reliability of road networks based on recursive decomposition arithmetic

In order to decrease the calculation complexity of connectivity reliability of road networks, an improved recursive decomposition arithmetic is proposed. First, the basic theory of recursive decomposition arithmetic is reviewed. Then the characteristics of road networks, which are different from general networks, are analyzed. Under this condition, an improved recursive decomposition arithmetic is put forward which fits road networks better. Furthermore, detailed calculation steps are presented which are convenient for the computer, and the advantage of the approximate arithmetic is analyzed based on this improved arithmetic. This improved recursive decomposition arithmetic directly produces disjoint minipaths and avoids the non-polynomial increasing problems. And because the characteristics of road networks are considered, this arithmetic is greatly simplified. Finally, an example is given to prove its validity.

Lazy loading algorithm for traffic assignment of road networks under fixed charge condition

The measures of path charge are important considerations in traffic assignment of road networks. Factors, such as travel time, fixed charge and traffic congestion which affect road users＇ choices of trip paths, are analyzed. Travelers usually decide their trip paths based on their personal habits, preferences and the information at hand. By considering both deterministic and stochastic factors which affect the value of time （VOT） during the process of path choosing, a variational inequality model is proposed to describe the problem of traffic assignment. A lazy loading algorithm for traffic assignment is designed to solve the proposed model, and the calculation steps are given. Numerical experiment results show that compared with the all-or-nothing assignment, the proposed model and the algorithm can provide more optimal traffic assignments for road networks. The results of this study can be used to optimize traffic planning and management.

成都预热“天府新区”

距离重庆两江新区正式挂牌不到三个月,近邻四川也有了大动作。9月1日,四川省召开深入实施西部大开发战略的工作会议,规划建设"天府新区",并将推动新区上升为国家战略。在为期两天的会议上,四川省委书记刘奇葆提出,要规划建设"天府新区",形成以现代制造业为主。

分析隧道火灾风险识别及安全保障技术

作为一种常用的交通方式,隧道除了能够使交通压力得以有效缓解,而且对于部分交通网路需要横跨江海、穿越山岭等困难得以解决,对于线路里程的缩短有着重要作用。然而,在隧道中,如果发生火灾事故,将会造成极为不利的影响。对此,在本文中,首先对隧道火灾风险识别进行了一定的分析,并在此基础上,对其安全保障措施进行了研究与探讨,仅供参考。

Analysis of Strategies to Improve Traffic Conditions in the Ancient Urban Area of Suzhou

In this paper, the authors first analyse the problems existing in the situation of land use, structure of travel mode and road network by applying the basic principle of traffic engineering and system engineering methods. Then, the authors make it clear the strategies to be adopted for solving the existing traffic problems in the ancient urban area of Suzhou(AUAS), namely insisting on the goal based strategy; the strategy to develop the public transit system in priority and decreasing the demand on cars from the view point of land use strategy. On the basis of such analysis the authors put forth proposals about major measures to be taken to improve traffic conditions of the AUAS, such as construction of express artery ring around the ancient city, appropriate transformation of the roads in the AUAS and rational distribution of car parking areas at the outskirt, which are of positive significance in guiding the protection of the AUAS and transportation construction. In this paper, specialized software is used to establish criteria for the construction scale and extent analysis and evaluation of the ancient city construction project, which is of some reference significance to the transformation of old urban areas in other cities.

Air Route Network Generation Based on Traffic Assignment

Air route network is the carrier of air traffic flow,and traffic assignment is a method to verify the rationality of air route network structure.Therefore,air route network generation based on traffic assignment has been becoming the research focus of airspace programming technology.Based on link prediction technology and optimization theory,a bi-level programming model is established in the paper.The model includes an upper level of air route network generation model and a lower level of traffic assignment model.The air route network structure generation incorporates network topology generation algorithm based on link prediction technology and optimal path search algorithm based on preference,and the traffic assignment adopts NSGA-Ⅲalgorithm.Based on the Python platform NetworkX complex network analysis library,a network of 57 airports,383 nodes,and 635 segments within China Airspace Beijing and Shanghai Flight Information Regions and 187975 sorties of traffic are used to simulate the bilevel model.Compared with the existing air route network,the proposed air route network can decrease the cost by 50.624%,lower the flight conflict coefficient by 33.564%,and reduce dynamic non-linear coefficient by 7.830%.

Vehicular emissions and concentrations in school zones: A case study

Recent research has revealed that human exposure to air pollutants such as CO, NO_x, and particulates can lead to respiratory diseases, especially among school-age children. Towards understanding such health impacts, this work estimates local-scale vehicular emissions and concentrations near a highway traffic network, where a school zone is located in. In the case study, VISSIM traffic micro-simulation is used to estimate the source of vehicular emissions at each roadway segment. The local-scale emission sources are then used as inputs to the California line source dispersion model(CALINE4) to estimate concentrations across the study area. To justify the local-scale emissions modeling approach, the simulation experiment is conducted under various traffic conditions. Different meteorological conditions are considered for emission dispersion. The work reveals that emission concentrations are usually higher at locations closer to the congested segments, freeway ramps and major arterial intersections. Compared to the macroscopic estimation(i.e. using network-average emission factors), the results show significantly different emission patterns when the local-scale emission modeling approach is used. In particular, it is found that the macroscopic approach over-estimates emission concentrations at freeways and under-estimations are observed at arterials and local streets. The results of the study can be used to compare to the US environmental protection agency(EPA) standards or any other air quality standard to further identify health risk in a fine-grained manner.

Optimal paths planning in dynamic transportation networks with random link travel times

A theoretical study was conducted on finding optimal paths in transportation networks where link travel times were stochastic and time-dependent(STD). The methodology of relative robust optimization was applied as measures for comparing time-varying, random path travel times for a priori optimization. In accordance with the situation in real world, a stochastic consistent condition was provided for the STD networks and under this condition, a mathematical proof was given that the STD robust optimal path problem can be simplified into a minimum problem in specific time-dependent networks. A label setting algorithm was designed and tested to find travelers' robust optimal path in a sampled STD network with computation complexity of O(n2+n·m). The validity of the robust approach and the designed algorithm were confirmed in the computational tests. Compared with conventional probability approach, the proposed approach is simple and efficient, and also has a good application prospect in navigation system.

Spatial Analysis of Commuting Mode Choice in Guangzhou, China

Metropolitan cities in China are commonly confronted with unresolved traffic congestion issues, primarily due to rapidly increasing traffic demand. Group disparity between commuting mode choice and its spatial distribution on road networks has enabled us to examine the factors that give rise to the discrepancies and the fundamental spatial causes of traffic congestion. In recent years, mi- cro-perspective, individual, and behavior-based spatial analysis have mushroomed and been facilitated with effective tools such as tem- poral geographic information systems （T-GIS）. It is difficult to study the interrelations between transport and space on the basis of commuting mode choice since the mode choice data are invisible in a specific space such as a particular road network. Therefore, in the field of transport, the classical origin destination （OD） four-stage model （FSM） is usually employed to calculate data when studying commuting mode choice. Based on the relative principles of T-GIS and the platform of ArcGIS, this paper considers Guangzhou as a case study and develops a spatio-temporal tool to examine the daily activities of residents. Meanwhile, the traffic volume distribution in rush hours, which was analyzed according to commuting modes and how they were reflected in the road network, was scrutinized with data extracted from travel diaries. Moreover, efforts were made to explain the relationship between traffic demand and urban spatial structure. Based on the investigation, this research indicates that traffic volumes in divergent groups and on the road networks is driven by： l） the socio-economie characteristics of travelers; 2） a jobs-housing imbalance under suburbanization; 3） differences in the spatial supply of transport modes; 4） the remains of the Danwei （work unit） system and market development in China; and 5） the transition of urban spatial structure and other factors.

Role of street patterns in zone-based traffic safety analysis

Although extensive analyses of road segments and intersections located in urban road networks have examined the role of many factors that contribute to the frequency and severity of crashes, the explicit relationship between street pattern characteristics and traffic safety remains underexplored. Based on a zone-based Hong Kong database, the Space Syntax was used to quantify the topological characteristics of street patterns and investigate the role of street patterns and zone-related factors in zone-based traffic safety analysis. A joint probability model was adopted to analyze crash frequency and severity in an integrated modeling framework and the maximum likelihood estimation method was used to estimate the parameters. In addition to the characteristics of street patterns, speed, road geometry, land-use patterns, and temporal factors were considered. The vehicle hours was also included as an exposure proxy in the model to make crash frequency predictions. The results indicate that the joint probability model can reveal the relationship between zone-based traffic safety and various other factors, and that street pattern characteristics play an important role in crash frequency prediction.

Real-time routing control design for traffic networks with multi-route choices

This work considers those road networks in which there are multi-route choices for bifurcation-destination(or origin-destination) pairs, and designs a real-time variable message sign(VMS)-based routing control strategy in the model predictive control(MPC) framework. The VMS route recommendation provided by the traffic management authority is directly considered as the control variable, and the routing control model is established, in which a multi-dimensional control vector is introduced to describe the influence of route recommendations on flow distribution. In the MPC framework, a system optimum routing strategy with the constraints regarding drivers' acceptability with recommended routes is designed, which can not only meet the traffic management authority's control requirement but also improve drivers' satisfaction with the route guidance system. The simulation carried out shows that the proposed routing control can effectively mitigate traffic congestion, reduces followers' time delay, and improves drivers' satisfaction with routing control in road networks.

Concept Paper： Developing Pavement Structural Deterioration Curves

A SN （structural number） can be calculated for a road pavement from the properties and thicknesses of the surface, basecourse, sub-base and subgrade. Historically, the cost of collecting structural data has been very high. Data was initially collected using Benkelman Beams and now by FWD （falling weight deflectometer）. The structural strength of pavements weakens over time due to environmental and traffic loading factors but due to a lack of data, no structural deterioration curve for pavements has been implemented in a PMS （pavement management system）. IRI （international roughness index） is a measure of the road longitudinal profile and has been used as a proxy for a pavement’s structural integrity. This paper offers two conceptual methods to develop PSDC （pavement structural deterioration curves）. Firstly, structural data are grouped in sets by design ESA （equivalent standard axles）. An ISN （“initial” SN）, SNI （intermediate SN） and a TSN （terminal SN）, are used to develop the curves. Using FWD data, the ISN is the SN after the pavement is rehabilitated （Financial Accounting “Modern Equivalent”）. Intermediate SNIs, are SNs other than the ISN and TSN. The TSN was defined as the SN of the pavement when it was approved for pavement rehabilitation. The second method is to use TSD （traffic speed deflectometer） data. The road network already divided into road blocks, is grouped by traffic loading. For each traffic loading group, road blocks that have had a recent pavement rehabilitation, are used to calculate the ISN and those planned for pavement rehabilitation to calculate the TSN. The remaining SNs are used to complete the age-based or if available, historical traffic loading-based SNIs.

Dynamic Routing Combined to Forecast the Behavior of Traffic in the City of Sao Paulo Using Neuro Fuzzy Network

The challenge of keeping and getting new customers drives the development of new practices to meet the consumption needs of increasingly tends to micro-segmentation of product and consumer market. The new consumption habits of brazilians brought new prospects for market. The objective of this paper is to develop of a dynamic vehicle routing system supported by the behavior of urban traffic in the city ofSao Paulo using Neuro Fuzzy Network. The methodology of this paper consists in the capture of relevant events that interfere with the flow of traffic of the city of Sao Paulo and implementation of a Fuzzy Neural Network trained with these events in order to foresee the traffic behavior. The system offers three labels of hierarchical routing, thus is possible to consider not only the basic factors of routing, but too external factors that directly influence on the flow of traffic and the disruption which may be avoided in large cities, through alternative routes （dynamic vehicle routing）. Predicting the behavior of traffic represents the strategic level routing, dynamic vehicle routing is the tactical level, and routing algorithms to the operational level. This paper will not be discussed the operational level.

Energy-Aware Traffic Routing with Named Data Networking

Greening Internet is an important issue now, which studies the way to reduce the increas- ing energy expenditure. Our work focuses on the network infrastructure and considers its energy awareness in traffic routing. We formulate the model by traffic engineering to achieve link rate a- daption, and also predict traffic matrices to pre- serve network stability. However, we realize that there is a tradeoff between network performance and energy efficiency, which is an obvious issue as Internet grows larger and larger. An essential cause is the huge traffic, and thus we try to fred its so- lution from a novel architecture called Named Data Networking （NDN） which tent in edge routers and can flexibly cache con- decrease the backbone traffic. We combine our methods with NDN, and finally improve both the network performance and the energy efficiency. Our work shows that it is effective, necessary and feasible to consider green- ing idea in the design of future Internet.

Traffic Signals Control with Adaptive Fuzzy Controller in Urban Road Network

An adaptive fuzzy logic controller (AFC) is presented for the signal control of the urban traffic network. The AFC is composed of the signal control system-oriented control level and the signal controller-oriented fuzzy rules regulation level. The control level decides the signal timings in an intersection with a fuzzy logic controller. The regulation level optimizes the fuzzy rules by the Adaptive Rule Module in AFC according to both the system performance index in current control period and the traffic flows in the last one. Consequently the system performances are improved. A weight coefficient controller (WCC) is also developed to describe the interactions of traffic flow among the adjacent intersections. So the AFC combined with the WCC can be applied in a road network for signal timings. Simulations of the AFC on a real traffic scenario have been conducted. Simulation results indicate that the adaptive controller for traffic control shows better performance than the actuated one.

Study on the Development of Water Transport Network for Passengers in the Gulshan-Banani-HatirJheel Lake of the Capital City of Bangladesh

Dhaka, the capital city of Bangladesh is one of the most overpopulated city in the world and traffic jam is the most severe and regular affliction in the daily life. Also, the existing vehicles are not sufficient in compared to the population of the city. People have to spend many hours simply sitting in the traffic jam. This lessens the productivity of people and brings sufferings to them. Gulshan-Banani-HatirJheel area is the busiest regions within the city and face severe traffic jam during working hours. These lakes are totally unused. Therefore, there is a possibility to build a waterways network for passengers transport through these lakes. This will reduce the affliction of people via reducing traffic jam. The proposed transportation networks will also preserve the natural environment of the lakes and bring a source of entertainment in the city life. Many developed cities in the world like London, New York, Paris, Venice, Shanghai etc. already have implemented waterways network inside the city and successfully made the best use of cistern side.