Maneuvers of motorcycles in queues at signalized intersections

The maneuvering models of motorcycles in previous studies often considered motorcycles' traveling in terms of movements in a physical static lane and not in terms of dynamic virtual lane‐based movements. For that reason, these models are not able to imitate motorcyclists' behavior well. This paper proposes a maneuverability model framework for motorcycles in queues at signalized intersections with considering the dynamic motorcycle's lane. The model includes (i) a dynamic motorcycle's lane to identify the current, left, and right lanes of the subject motorcycle, (ii) a threshold distance to determine when a motorcyclist starts to consider maneuvering, (iii) a lane selection model to identify the lane preferred by a motorcyclist, and (iv) a gap acceptance model to describe whether or not the lead and lag gaps are acceptable for maneuvering. The model framework captures the variation across the motorcyclist population and over time observations. The models were applied to Hanoi and Hochiminh city, Vietnam, based on microscopic data collected from video images. All of the parameters were estimated using the maximum likelihood method with the statistical estimation software GAUSS. The results show that 77.88% of the observed maneuvers – either staying in the current lane or turning left or right – could be modeled correctly by the proposed models. Copyright © 2010 John Wiley & Sons, Ltd.     

Pre-timed control for an under-saturated and over-saturated isolated intersection: a Bee Colony Optimization approach

In this paper we study the problem of determining the optimum cycle and phase lengths for isolated signalized intersections. Calculation of the optimal cycle and green phase lengths is based on the minimization of the average control delay experienced by all vehicles that arrive at the intersection within a given time period. We consider under-saturated as well as over-saturated conditions at isolated intersections. The defined traffic signal timing problem, that belongs to the class of combinatorial optimization problems, is solved using the Bee Colony Optimization (BCO) metaheuristic approach. The BCO is a biologically inspired method that explores collective intelligence applied by honey bees during the nectar collecting process. The numerical experiments performed on some examples show that the proposed approach is competitive with other methods. The obtained results show that the proposed approach is capable of generating high-quality solutions within negligible processing times.     

江北城地下道路系统规划与交通研究

江北城包括约2.0 km2的土地,是重庆规划中CBD的核心商务区,主要用于商务办公。依据江北城控制性详细规划,该区域开发密度很高。交通分析表明:以江北城目前的地面路网以及规划中的轻轨6号线和9号线,无法承担如此高强度开发产生的交通压力。提出了为缓解江北城的交通压力而规划的地下路网方案,介绍了对该路网的交通分析结果。     

现代有轨电车平交路口信号优先需求分析及苏州有轨电车实践方案

现代有轨电车线路多沿地面敷设,与道路平面交叉。为提高有轨电车通行效率,应在平交路口给予有轨电车优先通行权。结合苏州高新区有轨电车1号线的实际情况,分析并比较了有轨电车平交路口信号优先控制方案。详细描述了实时交互式方案的设计。实时交互式方案的灵活性、适用性好、安全性高,其控制策略易调整,便于管理,能较好地满足相关需求。     

公路平面交叉口交通安全改善设计研究

公路平面交叉口安全改善设计立足于改善平面交叉的道路条件和交通管制条件,合理解决各方向交通流的相互干扰和冲突,以保障交叉口的交通安全和畅通,提高交叉口的通行能力。通过对影响平面交叉口安全的相关因素分析,就渠化、行人过街安全、交通控制等方面进行探讨,并以具体工程实例说明其可行性,具有重要的现实意义。     

环形交叉口的流量测定方法探讨

通过观测环形交叉口的交通流量。并在研究典型十字环形交叉口与非常规交叉口的基础上．针对不同环形交叉口的实际情况提出采用切实可行的调查方法,并详细介绍调查方法的流程以及数据的整理与检验,可以很好地应用于实际调查工作中．从而为简化调查工作提供良好的策略。     

平面交叉口大型车辆右转安全性提升策略

针对目前平面交叉口大型车辆右转事故频发的突出安全问题,列举了国内几座城市的应对措施,分析产生事故的原因,并提出了减少冲突数量、路权保障、改善视距视区质量、ITS辅助等措施,为改善平面交叉口大型车辆右转安全性提供了参考。     

虎门中心商业区三个相邻交叉口交通组织研究

文中在道路条件、周边建筑和交通流量分析的基础上,综合运用了渠化措施、单向交通、信号控制及其他交通工程配套设施,详细介绍了虎门中心商业区三个相邻交叉口及其周边道路的交通组织,降低了交叉口复杂性,改善了交叉口的交通秩序。     

平面交叉口禁止左转效应分析

合理组织平面交叉口中的左转车流问题,与行车安全和通行能力有直接关系。禁止左转是平面交叉口组织的一个重要方式,它可能带来的交通效应与多种因素有关。从左转的交通特性出发,研究禁止左转后交叉口延误变化的机理和交通流的重新组织方式,得到禁止左转后交叉口延误变化的计算模型。通过模型分析认为,交叉口饱和度、路网密度和左转车流比例是影响交通效应的重要边界条件,并分析了这些边界条件对于禁止左转产生效应的影响方式。     

借用公交专用道左转的主预信号控制方案优化

设置有路中式公交专用道的交叉口进口道存在因公交与其他车辆两股平行车流在路口同时左转、直行和右转而形成的多路交织现象,传统信号控制方案已无法消除这类交叉口相位放行造成的交织冲突问题。为解决该问题,设计了一种借用公交专用道左转的新型交叉口,规定了各流向车辆的运行规则,同时设计了主信号与预信号相位方案及相互协调配时关系。具体来说,根据公交直行车辆和其他左转、直行车辆的到达-驶离图式,分别建立各流向不同情况下车辆的延误与停车次数计算方法,以交叉口车均延误与车均停车次数加权的当量费用最小为目标,建立交叉口信号配时优化模型。为验证该优化控制策略的有效性,结合算例对传统控制方案和优化控制方案进行比较,并分析等待区长度对车辆排队演化过程的影响,确定优化方案适用场景。结果表明：相对于传统方案,优化方案增加了交叉口的通行能力,使得车均当量费用下降比例达到了32.3%;参数灵敏度分析显示,主信号等待区长度宜设置为80 m。所提出的控制策略通过借用公交专用道左转,提高了交叉口的利用效率,最大限度地降低了对公交优先策略实施的影响,能够完全消除设置有路中式公交专用道交叉口相位放行中的交通交织冲突现象,以保证交叉口行车安全。