Pedestrian crosswalk overflow violation in China: Characteristics and countermeasure

The phenomenon that pedestrians do not walk in the crosswalk during pedestrian green is defined as overflow violation, which is illegal but common. Broadly varying crossing positions at far-side cross-section may result in widely distributed conflict points with left-turning and right-turning vehicles, which may cause the occurrence of severe conflicts. This paper proposes a model to estimate the overflow pedestrians’ crossing positions at the far-side cross-section of signalized crosswalk, which enables us to better understand pedestrian overflow violation behavior and finally facilitate their safety. After analysis, the intersection geometry and destination are determined as the critical factors causing pedestrians to overflow. And then, Weibull distribution is employed to describe the stochastic characteristics of overflow pedestrians’ crossing position distribution at the far-side cross-section. A crossing position distribution model which takes the crosswalk length, width and distance between crosswalk and destination into account is developed. The established model is validated by comparing the observed pedestrian crossing positions with the estimated crossing positions. The validation results suggest that the established model is capable of being adopted to estimate the overflow pedestrians’ crossing positions at far-side cross-section. Based on the model, countermeasure for overflow violation can be put forward to prevent pedestrians from walking outside the crosswalk.     

信控交叉口提前右转机动车与行人冲突特性

针对在信号交叉口提前右转且无信号控制的条件下,直右混行车道上右转车受直行车阻挡的问题,根据混行车道上交通流特性,确定了交叉口信号周期内提前右转机动车无法进入右转弯道的阻断时间,结合行人流上游所受的信号控制方式,解析了机动车与双向行人的冲突过程,计算了冲突中机动车与行人的通行时间,并在此基础上,建立了提前右转方式下右转车与行人的延误模型.案例计算与分析表明:模型计算值与实际调查值之间的相对误差在20%以内;当机动车流量小于350 pcu/h,机动车对行人通行影响较小,而当机动车流量大于350 pcu/h,行人与机动车的竞争冲突较为明显.      

考虑行人随机行为波动的改进社会力模型

为在仿真模型中更全面地反映行人特性,并研究随机行为对双向行人过街的影响,本文基于社会力模型建立了考虑行人随机行为的仿真模型.分析了随机行为对行人过街的影响,从速度和受力两个方面对行人随机行为进行建模,建立两个不同的行人随机行为模型.通过数值模拟,在双向行人比例1：1 的条件下,得到了考虑随机行为条件下行人的仿真轨迹和行人平均过街时间与行人总数的关系;此外在不同行人随机行为各向异性参数λ_αε 条件下,对比分析了仿真过街时间与经验模型过街时间.结果表明,行人随机行为导致过街时间增加,考虑随机行为后,改进模型二能够得到与实际相似的过街轨迹,当0.5<λ_αε <1时,改进模型二的行人仿真过街时间与利用经验模型得到的过街时间最为接近.