超高层综合体场地车行交通设计要点——以中海天府新区超高层为例

超高层综合体建筑多位于城市核心区,具有开发强度大、功能业态多样、交通发生量大、流线复杂、品质要求较高等特点。如何在有限的场地资源下清晰便捷地组织场地车行交通,形成建筑和城市的有效衔接,对项目交通组织以及城市交通高效运行都至关重要。本文以中海天府新区超高层为例,尝试分析超高层综合体场地车行交通设计要点,剖析超高层场地交通的生成逻辑。

山地换乘枢纽车行交通组织策略浅析

文章把山地换乘枢纽作为研究对象,发现山地换乘枢纽车行交通构成的系统性和特殊性。运用交通建筑和山地建筑的功能和交通组织的研究方法,对换乘枢纽交通组织特征进行了详细分析,归纳出建筑道路交通中车行流线的组织原则,最后总结交通组织要点提出策略。

车行地下交通空间总体布局模式初探

车行地下交通空间的开发对于减少地面交通拥堵,节约土地资源,减少噪音,保持城市原貌等方面,均具有积极意义。我国地下空间开发目前以综合交通枢纽和地铁建设为主,部分大城市在商业核心区或人流密集区已经开始建设车行地下交通空间。通过分析车行地下交通空间的各种布局模式,化繁为简,将复杂的地下交通空间分解为主隧道、出入口联通匝道两个部分进行研究,使得地下交通空间布局方案的研究流程具体化。

轨道车辆段综合体立体化交通组织研究——以广州石井水泥厂地块实践为例

轨道交通12号线是广州市地铁第一条全自动无人驾驶地铁线,线路全长37.6公里,起始于白云区浔峰岗站,终止于大学城南站,穿越白云、越秀、海珠、黄埔、番禺共5区,共设19个车站,由中国交建牵头组建的联合体中标实施建设工作。槎头车辆段综合体位于轨道交通12号线与13号线交汇处,将与凰岗停车场综合体、槎头站西地块综合体及西洲站综合体共同形成13号线二期沿线轨道综合开发发展轴,如图1所示。

转型期我国城市现代交通网络构建思辨

近年来,我国城市汽车化水平不断攀升,广大人民出行选择偏好于粗放、低效的方式,绿色、低碳、高效、集约的出行方式并未深入民心。我国城市现有的交通系统已无法适应广大人民不断增长的出行数量与质量要求,传统的宜居、绿色、祥和的生活空间淹没在猛如潮水的私家车洪流之中。在解析香港、新加坡、洛杉矶等国内外代表城市的交通网络构建经验基础上,提出应从完善法律创新制度、引导人民价值取向、加快多层次慢行网络建设、规范城市交通管理等方面推进我国现代城市交通体系发展,以期引领城市交通转型与创新发展,支撑城市发展目标实现和共享现代交通科技成果。

城市商业中心交通空间规划设计探讨

针对当前我国商业中心区交通空间存在的问题,探讨了商业中心区交通空间的规划设计方法,为创造和谐的商业中心区提供指导。

山地城镇的步行交通可持续发展研究

山地城镇地形复杂,步行和车行是主要的交通方式,而在山地城镇交通发展中步行交通多被认为是车行的结构性补充。本文针对山地城镇步行交通存在的问题,特别是和车行交通之间的矛盾,从人车关系演变出发,梳理了山地城镇人车之间的关系,明确了步行交通在山地城镇的必要性,提出了可持续的步行交通和车行交通整合措施。

Benzene and Toluene Levels Measured with DOAS During Vehicular Restrictions in Beijing

Measurements of atmospheric benzene and toluene were carried out continuously using dif- ferential optical absorption spectroscopy from August 7 to August 28 in Beijing during the period of vehicular restrictions. The correlations between traffic flows and totals of benzene and toluene were studied during the period of vehicular traffic restrictions from August 17 to August 20 and non-traffic restrictions on August 16 and August 21. The correlation coef- ficient was 0.8 between benzene and toluene. And the calculated daily mean value ratios of benzene to toluene were 0.43-0.50. During the period of vehicular restrictions, traffic flows were reduced about 11.8% and the levels of benzene and toluene were reduced by 11.4% and 12.8%, respectively. The vehicle emissions were recognized as the major sources for atmospheric benzene and toluene in Beijing.

探讨中小城市住宅建筑设计发展

通过分析近几年住宅设计中出现的新设计,新思路和新的功能空间,指出当前城市住宅设计已由"分得开、住得下"向"智能化、人性化、生态化"的设计思路发展。

Characteristics and risk of violation behavior of non-motorists at signalized intersections

Aiming at prevalent violations of non-motorists at urban intersections in China, this paper intends to clarify the characteristics and risks of non-motorist violations at signalized intersections through questionnaires and video recordings, which may serve as a basis for non-motorized vehicle management. It can help improve the traffic order and enhance the degree of safety at signalized intersections. To obtain the perception information, a questionaire survey on the Internet was conducted and 972 valid questionnaires were returned. It is found that academic degree contributes little to non-motorist violations, while electrical bicyclists have a relatively higher frequency of violations compared with bicyclists. The video data of 18 228 non-motorist behaviors indicate that the violation rate of all non-motorists is 26.5%; the number of conflicts reaches 1 938, among which violation conflicts account for 66.8%. The study shows that the violation rates and the violation behavior at three types of surveyed intersections are markedly different. It is also concluded that the conflict rates and the violation rates are positively correlated. Furthermore, signal violation, traveling in the wrong direction, and overspeeding to cross the intersection are the most dangerous among traffic violation behaviors.

海外传真

旧金山将新增12条“慢行街道”旧金山的交通管理政府官员正在计划在全市选择12条街道限制车辆通行,为行人和骑行者腾出更多的空间。旧金山市交通局将这项新计划命名为"慢行街道(Slow Streets)计划",宣布12条候选街道进入该计划的第一阶段"。慢行街道"的目标是管理交通速度,为步行和骑行者创建安全的网络,同时降低过境车行交通流量。第一阶段将采用临时标志、圆锥体等简单工具,进行交通分流,优化交通。

Relationship between number of passing events and operating parameters in mixed bicycle traffic

This paper investigates the passing events between electric bicycles and conventional bicycles and explores the relationships between passing events and traffic parameters in bicycle facilities.Three exclusive bicycle paths in Nanjing, China,were observed with cameras.Then,the field data including vehicle number,velocity characteristics and passing event features were analyzed in detail.Data analysis and fitting reveal that the speed difference has little impact on the passing event number,as does the bicycle ratio.The Gaussian function can better describe the relationship between the passing event number and bicycle volume （density）.The valid use level of bicycle path width influences the inflexion of the passing events-density fitting curve.The conclusions can be applied for estimating the passing events in mixed bicycle flows and for choosing a suitable width of separate bicycle path.

Development of control strategy of variable speed limits for improving traffic operations at freeway bottlenecks

A control strategy of variable speed limits(VSL)was developed to reduce the travel time at freeway recurrent bottleneck areas.The proposed control strategy particularly focused on preventing the capacity drop and increasing the discharge flow.A cell transmission model(CTM)was developed to evaluate the effects of the proposed VSL control strategy on the traffic operations.The results show that the total travel time is reduced by 25.5% and the delay is reduced by 56.1%.The average travel speed is increased by 34.3% and the queue length is reduced by 31.0%.The traffic operation is improved by the proposed VSL control strategy.The way to use the proposed VSL control strategy in different types of freeway bottlenecks was also discussed by considering different traffic flow characteristics.It is concluded that the VSL control strategy is effective for merge bottlenecks but is less effective for diverge bottlenecks.

Station Model for Rail Transit System Using Cellular Automata

In this paper, we propose a new cellular automata model to simulate the railway traffic at station. Based on NaSch model, the proposed station model is composed of the main track and the siding track. Two different schemes for trains passing through station are considered. One is the scheme of ＂pass by the main track, start and stop by the siding track＂. The other is the scheme of ＂two tracks play the same role＂. We simulate the train movement using the proposed model and analyze the traffic flow at station. The simulation results demonstrate that the proposed cellular automata model can be successfully used for the simulations of railway traffic. Some characteristic behaviors of railway traffic flow can be reproduced. Moreover, the simulation values of the minimum headway are close to the theoretical values. This result demonstrates the dependability and availability of the proposed model.

Particle swarm optimization for train schedule of Y-type train routing in urban rail transit

The train schedule usually includes train stop schedule,routing scheme and formation scheme.It is the basis of subway transportation.Combining the practical experience of transport organizations and the principle of the best match between transport capacity and passenger flow demand,taking the minimum value of passenger travel costs and corporation operating costs as the goal,considering the constraints of the maximum rail capacity,the minimum departure frequency and the maximum available electric multiple unit,an optimization model for city subway Y-type operation mode is constructed to determine the operation section of mainline as well as branch line and the train frequency of the Y-type operation mode.The particle swarm optimization(PSO)algorithm based on classification learning is used to solve the model,and the effectiveness of the model and algorithm is verified by a practical case.The results show that the length of branch line in Y-type operation affects the cost of waiting time of passengers significantly.

A new approach to quantifying vehicle induced turbulence for complex traffic scenarios

Traffic-related pollutants adversely affect air quality, especially in regions near major roadways. The vehicleinduced turbulence(VIT) is a significant factor that controls the initial dilution, dispersion, and ultimately the chemical and physical fate of pollutants by altering the conditions in the microenvironment. This study used a computational fluid dynamics(CFD) software FLUENT to model the vehicle-induced turbulence(VIT) generated on roadways, with a focus on impact of vehicle-vehicle interactions, traffic density and vehicle composition on turbulent kinetic energy(TKE). We show, for the first time, that the overall TKE from multiple vehicles traveling in series can be estimated by superimposing the TKE of each vehicle, without considering the distance between them while the distance is greater than one vehicle length. This finding is particularly significant since it enables a new approach to VIT simulations where the overall TKE is calculated as a function of number of vehicles. We found that the interactions between vehicles traveling next to each other in adjacent lanes are insignificant,regardless the directions of the traffic flow. Consequently, simulations of different traffic scenarios can be substantially simplified by treating two-way traffic as one-way traffic, with less than 5% difference in the overall volume-averaged TKE. We also developed equations that allow the estimation of the overall volume-averaged TKE as a function of the number and the type of vehicles.

Vehicle actuation based short-term traffic flow prediction model for signalized intersections

Traffic flow prediction is an important component for real-time traffic-adaptive signal control in urban arterial networks.By exploring available detector and signal controller information from neighboring intersections,a dynamic data-driven flow prediction model was developed.The model consists of two prediction components based on the signal states(red or green) for each movement at an upstream intersection.The characteristics of each signal state were carefully examined and the corresponding travel time from the upstream intersection to the approach in question at the downstream intersection was predicted.With an online turning proportion estimation method,along with the predicted travel times,the anticipated vehicle arrivals can be forecasted at the downstream intersection.The model performance was tested at a set of two signalized intersections located in the city of Gainesville,Florida,USA,using the CORSIM microscopic simulation package.Analysis results show that the model agrees well with empirical arrival data measured at 10 s intervals within an acceptable range of 10%-20%,and show a normal distribution.It is reasonably believed that the model has potential applicability for use in truly proactive real-time traffic adaptive signal control systems.

Pedestrianisation and Parking Policy as a Solution towards Green Transport Plan： A Case Study of Zagreb

Strategy of development trends in this moment and at this stage of the traffic comes from understanding the possibilities of the implementation of measures to raise the quality of movement and life in the city. It also includes planning and implementation of targeted interventions in the transport network or facilities. Mobility is a complex process in the area, starting from the departure from the apartment, using various means of transportation, a number of activities in different goals until to return to the location of the apartment. It thus requires extensive transport infrastructure in the form of walkways, bicycle paths, street and railway network. At the same time, reshaping of public transport facilities is needed in which the pedestrian, biker and green concept shall be the main elements of the new spatial conditions. Pedestrian zones development in the city means to create pedestrian areas and green islands in all the places in the city where possible. This process is essential for the transformation of public spaces, in particular, transport corridors. To accomplish the concept of the green transport plan, the need for change in the parking policy is emphasized. This should be an integral part of the city planning and should go hand in hand with the traffic policy.

Modeling electric vehicle's following behavior and numerical tests

The micro modeling for electric vehicle and its solution were investigated. A new car-following model for electric vehicle was proposed based on the existing car-following models. The impacts of the electric vehicle's charging electricity were studied from the numerical perspective. The numerical results show that the electric vehicle's charging electricity will destroy the stability of uniform flow and produce some prominent queues and these traffic phenomena are directly related to the initial headway, the distance between two adjacent charging stations and the number of charging stations. The above results can help traffic engineer to choose the position of charging station and the electric vehicle's driver to adjust his/her driving behavior in the traffic system with charging station.

Research on Behavior on Travel Mode, Going to Metro Station at Ho Chi Minh City

This research presents an analysis of travel mode choice for trips to Ho Chi Minh City metro station. Research methods were inherited through a formula to calculate passenger traffic forecasts to predict passengers, going to the station. Based on the collected data of interviews, traffic surveys, and ＂Irwin ＆ Von Cube＂ function, forecast the proportion of travel mode, and use to go to the station and leaving from the station. The results of study are used for the purpose of calculating the size of the metro station parking lots and parking layout plan.