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Effect of speed humps on instantaneous traffic emissions in a microscopic model with limited deceleration capacity
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作者 胡宇晨 李启朗 +2 位作者 刘军 王君霞 汪秉宏 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第6期413-420,共8页
As a common transportation facility, speed humps can control the speed of vehicles on special road sections to reduce traffic risks. At the same time, they also cause instantaneous traffic emissions. Based on the clas... As a common transportation facility, speed humps can control the speed of vehicles on special road sections to reduce traffic risks. At the same time, they also cause instantaneous traffic emissions. Based on the classic instantaneous traffic emission model and the limited deceleration capacity microscopic traffic flow model with slow-to-start rules, this paper has investigated the impact of speed humps on traffic flow and the instantaneous emissions of vehicle pollutants in a single lane situation. The numerical simulation results have shown that speed humps have significant effects on traffic flow and traffic emissions. In a free-flow region, the increase of speed humps leads to the continuous rise of CO_(2), NO_(X) and PM emissions. Within some density ranges, one finds that these pollutant emissions can evolve into some higher values under some random seeds. Under other random seeds, they can evolve into some lower values. In a wide moving jam region, the emission values of these pollutants sometimes appear as continuous or intermittent phenomenon. Compared to the refined Na Sch model, the present model has lower instantaneous emissions such as CO_(2), NO_(X) and PM and higher volatile organic components(VOC) emissions. Compared to the limited deceleration capacity model without slow-to-start rules, the present model also has lower instantaneous emissions such as CO_(2), NO_(X) and PM and higher VOC emissions in a wide moving jam region. These results can also be confirmed or explained by the statistical values of vehicle velocity and acceleration. 展开更多
关键词 traffic emissions speed humps slow-to-start rules deceleration capacity
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Capacity of Mixed Traffic Flow Crossing Multi-Major-Lanes 被引量:2
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作者 李文权 王炜 周刚 《Journal of Southeast University(English Edition)》 EI CAS 2000年第2期100-104,共5页
Based on the gap acceptance theory, the mixed traffic flow composed of r representative types of vehicles 1, 2,…, r vehicles is analyzed with probability theory. Capacity model of the minor mixed traffic flow ... Based on the gap acceptance theory, the mixed traffic flow composed of r representative types of vehicles 1, 2,…, r vehicles is analyzed with probability theory. Capacity model of the minor mixed traffic flow crossing m major lanes with M3 distributed headway on the unsignalized intersection is set up, and it is an extension of capacity model for one minor lane vehicle type crossing one major lane traffic flow. 展开更多
关键词 M3 distribution HEADWAY gap acceptance traffic flow capacity
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Research on service capacity of widened intersection based on traffic simulation
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作者 裴玉龙 程国柱 《Journal of Southeast University(English Edition)》 EI CAS 2003年第4期382-386,共5页
Delay analysis method is adopted to study the service capacity of a widened intersection. Traffic simulation software VISSIM is used for microscopic simulation of a widened intersection so as to obtain a delay curve. ... Delay analysis method is adopted to study the service capacity of a widened intersection. Traffic simulation software VISSIM is used for microscopic simulation of a widened intersection so as to obtain a delay curve. The delay-volume model of a widened intersection is established based on traffic simulation. The suggested value of basic service capacity of the widened left-turn lane is given along with how to determine correction factors and practical service capacity. 展开更多
关键词 traffic simulation widened intersection service capacity average delay
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An Algorithm for Traffic Equilibrium Flow with Capacity Constraints of Arcs 被引量:1
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作者 Zhi Lin 《Journal of Transportation Technologies》 2015年第4期240-246,共7页
In the traffic equilibrium problem, we introduce capacity constraints of arcs, extend Beckmann’s formula to include these constraints, and give an algorithm for traffic equilibrium flows with capacity constraints on ... In the traffic equilibrium problem, we introduce capacity constraints of arcs, extend Beckmann’s formula to include these constraints, and give an algorithm for traffic equilibrium flows with capacity constraints on arcs. Using an example, we illustrate the application of the algorithm and show that Beckmann’s formula is a sufficient condition only, not a necessary condition, for traffic equilibrium with capacity constraints of arcs. 展开更多
关键词 The traffic EQUILIBRIUM Problem with capacity Constraints of ARCS EQUILIBRIUM FLOW ALGORITHM capacity of ARC Saturated PATH
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Mixed Traffic Flow Capacity of More Major Lanes Unsignalized Intersection 被引量:1
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作者 TIAN Xin-xian 《Chinese Quarterly Journal of Mathematics》 CSCD 北大核心 2008年第3期462-469,共8页
Highway capacity is defined as maximum volume of traffic flow through the particular highway section under given traffic conditions, road conditions and so on. Highway construction and management is judged by capacity... Highway capacity is defined as maximum volume of traffic flow through the particular highway section under given traffic conditions, road conditions and so on. Highway construction and management is judged by capacity standard. The reasonable scale and time of highway construction, rational network structure and optimal management mode of highway network can be determined by analyzing the fitness between capacity and traffic volume. All over the world, highway capacity is studied to different extent in different country. Based on the gap acceptance theory, the mixed traffic flow composed of two representative vehicle types heavy and light vehicles is analyzed with probability theory. Capacity model of the minor mixed traffic flows crossing m major lanes, on which the traffic flows fix in with M3 distributed headway, on the unsignalized intersection is set up, and it is an extension of minor lane capacity theory for one vehicle-type and one major-lane traffic flow. 展开更多
关键词 HEADWAY gap acceptance mixed traffic flow highway capacity
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Calibrating HCM model for roundabout entry capacity under heterogeneous traffic
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作者 Abdullah Ahmad Rajat Rastogi 《Journal of Modern Transportation》 2019年第4期293-305,共13页
Roundabout is a channelized intersection where traffic moves around a central island,clockwise for leftside driving and anti-clockwise for right-side driving.Efficiently designed roundabouts can handle traffic very sm... Roundabout is a channelized intersection where traffic moves around a central island,clockwise for leftside driving and anti-clockwise for right-side driving.Efficiently designed roundabouts can handle traffic very smoothly without causing any delay.The capacity of roundabouts used to be calculated by the weaving theory in India.However,calculation of the entry capacity in the recent literature is based on critical gaps and follow-up times,and the Highway Capacity Manual of US(HCM2010)provides an equation to estimate the entry capacity of a roundabout by using the flow in passenger car unit per hour(PCU/h),critical gaps and follow-up times at the entry section.In order to examine whether the HCM equation applies to Indian traffic condition or not,we collected data from five roundabouts in India in this study.Relevant data were extracted/estimated to calibrate parameters of the HCM equation.The PCU for a vehicle was estimated on the basis of lagging headway and width of the vehicle,and the critical gap value for a vehicle was estimated by minimizing the sum of absolute difference in a gap with respect to the highest rejected and accepted gaps.Results show that the critical gap values obtained under heterogeneous traffic conditions are much lower than those given in the literature for homogeneous traffic conditions.In addition,the modified HCM equation based on the critical gap values was verified using the field data taken during the formation of a continuous and stable queue at the entry of a roundabout.It was found that a multiplicative adjustment factor needs to be calculated for different sizes of roundabouts to ensure the adjusted HCM equation represents well the traffic condition prevailing in developing countries like India.A test conducted at another roundabout validated that the entry capacity estimated from the calibrated and adjusted HCM model was consistent with the field entry capacity,and the calibrated and adjusted HCM model could predict the entry capacity of an approach to a roundabout quite accurately. 展开更多
关键词 ROUNDABOUT ENTRY capacity HCM Heterogeneous traffic GAP ACCEPTANCE
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A Model for Capacity Considering the Interference by Pedestrian Traffic at Signal Intersections
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作者 Yixin Chen Yulong He Xiaoduan Sun 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2016年第1期82-89,共8页
The capacity is impacted badly by pedestrians' violation behavior at signal intersections. In order to quantify the impact,the time-headway and the vehicular speed from start-up to reach the stable saturation flow... The capacity is impacted badly by pedestrians' violation behavior at signal intersections. In order to quantify the impact,the time-headway and the vehicular speed from start-up to reach the stable saturation flow with and without pedestrian traffic are used as the direct measurements. Using the statistical analysis,the timeheadway of saturation flow is mainly affected by the position of pedestrians and the degree of pedestrians 'influence is classified into four levels. Then the speed-time profile for the vehicular acceleration at each level is fitted by Curve Fitting Software. Based on the effect to the time-headway and acceleration time,the model of capacity influenced by pedestrians is established and the influence is quantified, which enriches the fundamental theory of traffic engineering. The result shows that the vehicular capacity can be decreased by 14%at the worst case( level I). The conclusions obtained in this paper are valuable for better management of the signal intersection. 展开更多
关键词 urban traffic capacity impact of pedestrians significant analysis
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A NEW SYNCHRONOUS DIGITAL HIERARCHICAL BI-DIRECTIONAL RING CAPACITY DESIGN ALGORITHM BASED ON THE SHORTEST-ROUTE TRAFFIC MATRIX
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作者 Long Keping Cheng Shiduan(National Lab. of Switching Tech. and Telecommun. Networks, Beijing Univ. of Posts and Telecommun., Beijing 100876)Liu Hui(Chongqing University of Posts and Telecommunications, Chongqing 630065)Huang Xiangfu (Inst, of Elec. Eng., UEST of China, Chengdu 610054) 《Journal of Electronics(China)》 1999年第2期123-129,共7页
In this paper, the concept of the Shortest-Route Traffic Matrix(SRTM) was first presented, and the generalized formula for computing ring capacity requirement in use of SRTM is given. Then, a new capacity design algor... In this paper, the concept of the Shortest-Route Traffic Matrix(SRTM) was first presented, and the generalized formula for computing ring capacity requirement in use of SRTM is given. Then, a new capacity design algorithm which is based on SRTM was presented for Synchronous Digital Hierarchical(SDH) Bi-directional Self-Healing Ring (BSHR). The algorithm simulation results demonstrate that this algorithm is very efficient for SDH BSHR capacity design and can make less project investment and make high utilization of lines and equipment. By means of the algorithm in this paper, capacity optimization assignment for SDH Hierarchical Self-Healing Ring (HSHR) and for ATM Virtual Path (VP)-based Self-Healing Ring (SHR) is also discussed. 展开更多
关键词 Bi-directional SELF-HEALING RING RING capacity requirement Shortest-route traffic matrix SYNCHRONOUS DIGITAL Hierarchical(SDH)
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Capacity models on expressway near a bus bay stop with an access 被引量:3
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作者 张洪宾 孙小端 +1 位作者 贺玉龙 宇仁德 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第8期3239-3246,共8页
To determinate the expressway capacity near a bus bay stop with an access, capacity models on the expressway near a bus stop with an access were developed on the basis of gap acceptance theory and queuing theory. Depe... To determinate the expressway capacity near a bus bay stop with an access, capacity models on the expressway near a bus stop with an access were developed on the basis of gap acceptance theory and queuing theory. Depending on a bus stop position to an entrance or an exit ramp, the capacity models were developed for four cases. Bus bay stops with overflow and bus bay stops without overflow were considered. A comparison of simulation experiment and model calculation was carried out. Results show that the suggested models have high accuracy and reliability, at bus arrival rate below 60 vehicles per hour(veh/h) or vehicle volumes at the entrance and the exit below 200 passenger cars units per hour(pcu/h), and there are no significant difference in the capacities for four cases. When bus arrival rate is above 240 veh/h, the capacities of all four cases will decline rapidly. With berth number increasing, the increasing of the capacities is no obvious for four cases. As the bus arrival rate and vehicle volumes at the entrance and the exit increase, bus stops located downstream of an entrance and upstream of an exit have a remarkably effect on the capacities. The latter case is much heavier than the former. Those results can be used to traffic design and optimization on urban expressway near a bus stop with an access. 展开更多
关键词 capacity public transport entrance and exit traffic flow theory DELAY
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Cellular automation model for analyzing capacity of branch road section 被引量:2
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作者 王英姿 龙东方 史峰 《Journal of Central South University》 SCIE EI CAS 2011年第5期1744-1749,共6页
In order to reduce the traffic pressure of urban arterial road with the rational utilization of the branch road,the vehicle meeting behavior on the branch road without divided lane was described,and the cellular autom... In order to reduce the traffic pressure of urban arterial road with the rational utilization of the branch road,the vehicle meeting behavior on the branch road without divided lane was described,and the cellular automation (CA) model was put forward by introducing meeting behavior to reflect the relation between safe meeting speed and road width.The numerical simulation results depict several relation curves between road section capacity,speed and road width under different directional distributions of traffic flow,as well as the curves between the major and minor direction saturation flow,speed and road width.These relation characteristics indicate that except the one-way road section capacity and speed remaining unchanged,other road section capacities and speeds under different directional distributions increase with the increase of road width.On narrow road,the two-way traffic capacity and speed are less than those of one-way traffic;on wide road,the two-way traffic capacity doubles that of one-way traffic,but their speeds are almost the same.As the directional distribution moves to an even distribution of 50/50,the major direction saturation flows and speeds as well as the minor direction speeds tend to decease,while the minor direction saturation flow tends to increase. 展开更多
关键词 urban traffic road section capacity safe meeting speed cellular automation model
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Bicycle capacity of borrowed-priority merge at unsignalized intersections in China
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作者 杨小宝 环梅 +1 位作者 四兵锋 高亮 《Journal of Beijing Institute of Technology》 EI CAS 2012年第2期229-233,共5页
To investigate bicyclists' behavior at unsignalized intersections with mixed traffic flow, a bicycle capacity model of borrowed-priority merge was developed by the addition-conflict-flow procedure. Based on the actua... To investigate bicyclists' behavior at unsignalized intersections with mixed traffic flow, a bicycle capacity model of borrowed-priority merge was developed by the addition-conflict-flow procedure. Based on the actual traffic situation, the concept of borrowed priority, in which the majorroad bicycles borrow the priority of major-road cars to enter the intersections when consecutive headway for major-steam cars is lower than the critical gap for minor-road cars, was addressed. Bicycle capacity at a typical unsignalized intersection is derived by the addition-conflict-flow procedure. The proposes model was validated by the empirical investigation. Numerical results show that bicycle capacity at an intersection is the function of major-road and minor-road car streams. Bicycle capacity increases with increasing major-road cars but decreases with increasing minorroad cars. 展开更多
关键词 mixed traffic flow unsignalized intersection bicycle capacity PRIORITY
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Method for Evaluating Instantaneous Sector Capacity
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作者 赵征 杨磊 +1 位作者 胡明华 刘国毅 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2015年第5期571-578,共8页
A method for evaluating instantaneous sector capacity based on the workload of air traffic controller(ATC)is developed.The basic characteristics of the assessed sector is described and a model to correlate the workloa... A method for evaluating instantaneous sector capacity based on the workload of air traffic controller(ATC)is developed.The basic characteristics of the assessed sector is described and a model to correlate the workload with the instantaneous sector capacity is developed using workload data.The correlation between the regional sector/approach sector capacity and the traffic flow organization is analyzed.Experimental results show that the instantaneous sector capacity assessment is reasonable and the instantaneous capacity is strongly correlated with the spatial and temporal distributions of the traffic flow and the sector operation mode.These results can provide an important reference for sector operation safety,capacity prediction,air traffic management,and airspace design. 展开更多
关键词 air traffic controller(ATC)workload control sector instantaneous capacity
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Comparative Study of Methods Used for a Capacity Estimation on Two Lane Undivided National Highways
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作者 Vijay B.G. Rajendra Khatavkar 《Journal of Traffic and Transportation Engineering》 2019年第1期29-37,共9页
In these days the traffic is expanding quickly and the activity conditions on Indian roads are exceedingly heterogeneous in nature because of variety of vehicles with various static and dynamic qualities.Due to unrest... In these days the traffic is expanding quickly and the activity conditions on Indian roads are exceedingly heterogeneous in nature because of variety of vehicles with various static and dynamic qualities.Due to unrestricted movements all fast and slow moving vehicles without any separation,the roads will face severe congestion and lower speeds.The greater part of national and state highways in India are two lane undivided roadway.These two lane highways achieve its greatest limit soon and require consistent up gradation to do this we need to estimate capacity of selected roads.In this present paper,attempts have been made to collect traffic volume for whole 7 days at national highways such as NH-206&NH-209.Also tried to compute PCU values at selected stretches on highways by using those values attempts has been made to estimate capacity and to compare those values with the regression equation values.Finally from the present study we got ADT at different section on highways,calculated PCU values as per Chandra’s method at various sections on highways and got marginal difference with the values recommended by IRC.It is found that with the increase in lane width,speed and radius substantially caused increased in PCU value.Also we developed linear regression equations to estimate capacity and compared those values with the values as we got using Chandra’s method.In most of the cases the error is observed to be less than 3%.The percentage error is in the range between 0.02 and 2.41 which is very marginal.Finally from the study it has been observed that increase in lane width and radius at curves obviously increases the capacity their by increases both comfort and safety of the road users. 展开更多
关键词 traffic VOLUME COUNT PCU mean SPEED capacity linear regression EQUATION
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Aspects of Railway Capacity and Occupation Time Estimation
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作者 Jozef Gasparik Vladislav Zitricky 《Journal of Civil Engineering and Architecture》 2014年第3期322-331,共10页
The priority of the EU transport policy in railway sector is to open up the railway market. The objective is to provide railway undertakings with access to the railway network on equal terms. The main problem is deter... The priority of the EU transport policy in railway sector is to open up the railway market. The objective is to provide railway undertakings with access to the railway network on equal terms. The main problem is determining the infrastructure capacity. A variety of methodologies are used across Europe for the capacity estimation of railway infrastructure. This diversity has forced railway infrastructure managers to seek a new, common methodology. The UIC methodology is an easy way to calculate the capacity consumption. However, there the possibility to expound this methodology in different ways, which can result in different capacity consumptions. There isan advantage to improve this methodology and to set a clear and unified method of occupation time estimation. The fundamental improvement to UIC methodology is the definition of the occupation time by the trains. This paper gives a description of Slovak and UIC methodologies as a basis for a newly developed approach. The new way of estimation of the capacity consumption (occupation time) is based on a graphic approach. The new methodology concerns the estimation of the infrastructure occupation time and is a conceptual framework developed by the authors for an easier evaluation of occupation time in train traffic diagrams. The new methodology makes the UIC methodology more usable and enables more exact results to be obtained from infrastructure capacity examination. 展开更多
关键词 Methodology for capacity estimation train traffic diagram occupation square occupation rate buffer time.
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Stochastic Air Traffic Flow Management for Demand and Capacity Balancing Under Capacity Uncertainty
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作者 CHEN Yunxiang XU Yan ZHAO Yifei 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2024年第5期656-674,共19页
This paper introduces an innovative approach to the synchronized demand-capacity balance with special focus on sector capacity uncertainty within a centrally controlled collaborative air traffic flow management(ATFM)f... This paper introduces an innovative approach to the synchronized demand-capacity balance with special focus on sector capacity uncertainty within a centrally controlled collaborative air traffic flow management(ATFM)framework.Further with previous study,the uncertainty in capacity is considered as a non-negligible issue regarding multiple reasons,like the impact of weather,the strike of air traffic controllers(ATCOs),the military use of airspace and the spatiotemporal distribution of nonscheduled flights,etc.These recessive factors affect the outcome of traffic flow optimization.In this research,the focus is placed on the impact of sector capacity uncertainty on demand and capacity balancing(DCB)optimization and ATFM,and multiple options,such as delay assignment and rerouting,are intended for regulating the traffic flow.A scenario optimization method for sector capacity in the presence of uncertainties is used to find the approximately optimal solution.The results show that the proposed approach can achieve better demand and capacity balancing and determine perfect integer solutions to ATFM problems,solving large-scale instances(24 h on seven capacity scenarios,with 6255 flights and 8949 trajectories)in 5-15 min.To the best of our knowledge,our experiment is the first to tackle large-scale instances of stochastic ATFM problems within the collaborative ATFM framework. 展开更多
关键词 air traffic flow management demand and capacity balancing flight delays sector capacity uncertainty ground delay programs probabilistic scenario trees
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考虑构件震害影响的城市桥梁震后通行功能损失评估方法
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作者 李天翊 张东昱 张晓宇 《哈尔滨工业大学学报》 EI CAS 北大核心 2025年第1期35-45,共11页
桥梁作为城市交通网络重要节点,其车辆通行能力在震后救灾和重建过程中起着至关重要的作用。但现有城市桥梁震后损失研究多集中于结构损伤维修成本方面,对桥梁震后车辆通行功能损失研究关注不足,难以为震后紧急救援和桥梁修复决策提供... 桥梁作为城市交通网络重要节点,其车辆通行能力在震后救灾和重建过程中起着至关重要的作用。但现有城市桥梁震后损失研究多集中于结构损伤维修成本方面,对桥梁震后车辆通行功能损失研究关注不足,难以为震后紧急救援和桥梁修复决策提供有效指导。因此,本文提出了综合考虑桥梁构件震害破坏及其对车辆通行影响的桥梁震后通行功能损失评估方法。首先,为了更准确地分析地震对桥梁结构整体系统的影响,采用copula函数,开展了考虑桥梁构件破坏相关性的桥梁系统地震易损性分析;其次,提出了地震导致桥梁车辆通行能力损失的评估方法。该方法综合考虑了桥梁结构损伤、承载力下降导致的开放车道减少以及桥梁伸缩缝损坏导致的车辆行驶速度降低等因素影响,因而可以更准确地反映震后桥梁车辆通行能力;最后,通过一个4跨连续梁桥算例发现相较于现有评估方法,本文提出的城市桥梁震后通行功能损失评估方法具有准确度更高、离散程度和不确定性更小的特点。与传统的定性和主观震后桥梁功能损失评估方法相比,本项研究提出的分析方法从物理层面考虑了桥梁构件震害对桥梁车辆通行能力的具体影响,为震后决策过程提供了一个数学模型。 展开更多
关键词 桥梁易损性 构件破坏相关性 车辆通行能力 桥梁通行功能损失
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Mixed traffic flow modeling near Chinese bus stops and its applications 被引量:5
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作者 杨小宝 四兵锋 环梅 《Journal of Central South University》 SCIE EI CAS 2012年第9期2697-2704,共8页
To determine how bus stop design influences mixed traffic operation near Chinese bus stops,a new theoretical method was developed by using additive-conflict-flows procedure.The procedure was extended from homogeneous ... To determine how bus stop design influences mixed traffic operation near Chinese bus stops,a new theoretical method was developed by using additive-conflict-flows procedure.The procedure was extended from homogeneous traffic flow to mixed traffic flow.Based on the procedure and queuing theory,car capacity and speed models were proposed for three types of bus stops including curbside,bus bay and bicycle detour.The effects of various combinations of bus stop type,traffic volume,bus dwell time,and berth number on traffic operations were investigated.The results indicate that traffic volume,bus dwell time and berth number have negative effects on traffic operations for any type of bus stops.For different types of bus stops,at car volumes above approximately 200 vehicles per hour,the bus bay and bicycle detour designs provide more benefits than the curbside design.As traffic volume increases,the benefit firstly increases in uncongested conditions and then decreases in congested conditions.It reaches the maximum at car volumes nearly 1 100 vehicles per hour.The results can be used to aid in the selection of a preferred bus stop design for a given traffic volume in developing countries. 展开更多
关键词 mixed traffic flow bus stop road capacity SPEED bicycles
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Degradation of a protected mountain area by tourist traffic:case study of the Tatra National Park,Poland 被引量:3
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作者 Joanna FIDELUS-ORZECHOWSKA Elzbieta GORCZYCA +1 位作者 Marcin BUKOWSKI Kazimierz KRZEMIEN 《Journal of Mountain Science》 SCIE CSCD 2021年第10期2503-2519,共17页
Mountain protected areas are characterized by high biodiversity,which makes it a great challenge for managers to maintain a balance between their use and the stability of natural ecosystems.Maintaining that balance is... Mountain protected areas are characterized by high biodiversity,which makes it a great challenge for managers to maintain a balance between their use and the stability of natural ecosystems.Maintaining that balance is particularly difficult in areas with high tourism pressure.The expected volume of tourist traffic should be considered at the planning stage of the tourist infrastructure development process.Insufficient capacity of tourist infrastructure can lead to environmental degradation,which is hard,or at times impossible,to repair.In our research,we identified patterns of tourist footpath and road functioning in an environmentally protected area with high volumes of tourist traffic.Data from geomorphologic mapping was analyzed in order to identify tourist footpath and road structures in the Tatra National Park(TNP).Fieldwork was conducted in several stages between 1995 and 2019.Orthophotomaps from the years 1977,2009,2017 and 2019 were used to identify and compare degraded zones along selected tourist footpaths.Degraded zones were defined as areas surrounding a footpath or tourist road with a mean width larger than or equal to 10 meters,with heavily damaged or completely removed vegetation and exposed,weathered cover,where geomorphic processes that would not take place under normal conditions are readily observable.The examined tourist footpaths and roads vary in terms of their morphometric parameters.Research has shown important differences between mean and maximum footpath width as well as maximum incision depth for the forest zone versus the subalpine and alpine zones.A lack of differences in these parameters was noted between the alpine and subalpine zones.Research has shown that an increase in the surface area of degraded zones found adjacent to tourist footpaths occurred in all the studied geo-ecological zones in the study period.However,the largest increase occurred atop wide ridgelines found in the alpine zone.Degraded zones may be an indication of exceeding the tourist carrying capacity of a mountain tourist area.Mass tourism in TNP contributes to the formation of degraded zones adjacent to footpaths,whose continuous evolution may lead to irreversible changes in local relief. 展开更多
关键词 Tourist traffic Degraded zones Mountain area Morphogenetic processes Carrying capacity
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Urban One-way Traffic Organization and Its Evaluation 被引量:2
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作者 裴玉龙 伊新苗 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2004年第2期121-124,共4页
One-way traffic organization is a direct, efficient and economic method to solve traffic congestion and expand traffie capacity. With its evolution, advantages and disadvantages introduced its setting conditions demon... One-way traffic organization is a direct, efficient and economic method to solve traffic congestion and expand traffie capacity. With its evolution, advantages and disadvantages introduced its setting conditions demonstrated. The general method and processes are summarized in planning for urban one-way streets project, viz. investigation, drawing out and evaluation of project, selecting of project and beneficial analysis. Fuzzy synthetical evaluation other fields is employed to evaluate the project. Its evaluation system and method is introduced and Delphi method is adopted to obtain evaluation index. Finally, taking Harbin city as an example, the application process of above-mentioned method is illuminated. Accordingly, it is proved that the method is exercisable. 展开更多
关键词 one-way traffic organization traffic congestion traffic capacity
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Research on traffic flow forecasting model based on cusp catastrophe theory 被引量:2
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作者 张亚平 裴玉龙 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2004年第1期1-5,共5页
This paper intends to describe the relationship between traffic parameters by using cusp catastrophe theory and to deduce highway capacity and corresponding speed forecasting value through suitable transformation of c... This paper intends to describe the relationship between traffic parameters by using cusp catastrophe theory and to deduce highway capacity and corresponding speed forecasting value through suitable transformation of catastrophe model. The five properties of a catastrophe system are outlined briefly, and then the data collected on freeways of Zhujiang River Delta, Guangdong province, China are examined to ascertain whether they exhibit qualitative properties and attributes of the catastrophe model. The forecasting value of speed and capacity for freeway segments are given based on the catastrophe model. Furthermore, speed-flow curve on freeway is drawn by plotting out congested and uncongested traffic flow and the capacity value for the same freeway segment is also obtained from speed-flow curve to test the feasibility of the application of cusp catastrophe theory in traffic flow analysis. The calculating results of catastrophe model coincide with those of traditional traffic flow models regressed from field observed data, which indicates that the deficiency of traditional analysis of relationship between speed, flow and occupancy in two-dimension can be compensated by analysis of the relationship among speed, flow and occupancy based on catastrophe model in three-dimension. Finally, the prospects and problems of its application in traffic flow research in China are discussed. 展开更多
关键词 capacity cusp catastrophe model speed-flow curve traffic flow forecasting
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