干线控制策略对宏观基本图特征影响研究

Influence of Artery Coordinated Control Strategies on Macroscopic Fundamental Diagram

相比单交叉口控制,交叉口群协调控制策略的评价与优化方法尚不完善、控制参数优化原则尚不明确。基于宏观基本图(MFD)的研究发展,提出引用宏观基本图作为交通控制决策的评判手段,建立并分析MFD形态与交通控制参数(信号周期、相位差)的量变关系,以支撑信号控制决策。通过实测与仿真数据相结合的方式,验证了宏观基本图在上海张杨路的存在性,及宏观基本图形态对控制策略的敏感性。建立不同等间距的标准路网仿真模型,获取了MFD与控制参数的量变关系,并结合宏观基本图与路网评价指标(等效通行能力、自由流车速、延误等),分析了不同信号周期和相位差的适用条件。结果表明,路网等效通行能力并不单纯随周期的增大而增加,且存在使路网通行能力最大的“最佳”周期;路网自由流车速随信号周期的增加而减小。同步控制适用于交叉口间距较小(小于200 m)情况,续进控制适用于交叉口间距较大(大于300 m)情况。

Compared with single intersection control,evaluations and optimization methods of grouped intersection control strategies remain unclear.By analyzing quantitative relationships between MFD and traffic control parameters(i.e.signal period,phase difference,etc.),the MFD is used to evaluate control strategies for arterial roads.With observed and simulated data,the existence of MFD on Shanghai Zhangyang Road is verified,as well as the sensitivity of MFD to the control strategies.The quantitative relationships between MFD and control parameters are clarified by standard network simulation models.The applicable conditions of cycle length and offset are analyzed with the MFD and evaluation indices(i.e.equivalent capacity,free-flow speed,delay,etc.).The results show that the equivalent capacity does not simply increase with the increase of cycle length,and the“optimum”cycle length can maximize the equivalent capacity.The free-flow speed decreases with the increase of signal period.Synchronous control is more suitable for intersections with distance less than 200 m,yet progressive control is more appropriate for intersections with a larger distance more than 300 m.