Signalized intersections sometimes involve multistage pedestrian crossings, in which pedestrians cross to one or more islands and then wait there for a signal to continue. When signals are timed without attention to p...Signalized intersections sometimes involve multistage pedestrian crossings, in which pedestrians cross to one or more islands and then wait there for a signal to continue. When signals are timed without attention to pedestrian progression, pedestrian delay at multistage crossings can be very long. This paper addresses two issues. First, pedestrian delay at multistage crossings is rarely evaluated because there are no tools in the industry for that purpose except microsimulation. We present a numerical method for determining crossing delay with any number of stages and with the possibility of multiple WALK intervals per cycle. The same method can be applied to single stage crossings, to diagonal two-stage crossings where pedestrians may have path choice, and bicycle two-stage turns. This method has been implemented in a freely available online tool. Second, we describe several signal timing techniques for improving pedestrian and bicyclist progression, and thus reducing their delay, through multistage crossings. They include reservice for selected crossing phases, left turn overlaps, having pedestrian phases overlap each other, and bidirectional bicycle crossings which create path options for two-stage turns. Examples show the potential for large reductions in pedestrian delay, often with little or no increase in vehicular delay. In one example, the addition of a short pedestrian overlap phase reduced average pedestrian delay at a 3-stage crossing by 82 s while average vehicular delay increased by only 0.5 s.展开更多
The effects of the interactions between bi-directional pedestrians on the crossing time and the crosswalk width are studied. Firstly,the crossing process of bi-directional pedestrians is analyzed.The total crosswalk t...The effects of the interactions between bi-directional pedestrians on the crossing time and the crosswalk width are studied. Firstly,the crossing process of bi-directional pedestrians is analyzed.The total crosswalk time is divided into a discharge time and a crossing time. The interactions between bi-directional pedestrians are quantified with the drag force theory. Then,a model is developed to study the crossing time based on the kinetic energy theory and momentum theory. Subsequently,the related parameters of the proposed model are calibrated with observed information. The relationships among crosswalk width,signal time,pedestrian volume and level of service are simulated with the proposed model. The results are verified and compared with other models. The proposed model has an absolute value of relative error of 9. 38%,which is smaller than that of the Alhajyaseen model（ 15. 26%） and Highway Capacity Manual（ HCM） model（ 12. 42%）. Finally,suggested crosswalk widths at different conditions are successfully estimated with the proposed crossing time model.展开更多
The pedestrian crossing speed is one of the important factors in pedestrian crossing facility design.Research studies have shown that the pedestrian crossing speed is influenced by availability of green time at signal...The pedestrian crossing speed is one of the important factors in pedestrian crossing facility design.Research studies have shown that the pedestrian crossing speed is influenced by availability of green time at signalized crosswalks and pedestrian characteristics such as gender and age.However,the effects of vehicular time gap and additional pedestrian behavioural characteristics on pedestrian crossing speed patterns have not been examined at unprotected(un-signalized)mid-block crosswalks.The present study examines the pedestrian crossing speed change patterns considering the effect of vehicular time gap and pedestrian behavioural characteristics such as rolling behaviour,path change,etc.,at selected unprotected mid-block crosswalk locations under mixed traffic conditions in India.Video graphic survey has been conducted at eight selected unprotected mid-block crosswalk locations in Mumbai City for two to three hours duration during normal weather conditions.The data was mined using AVS video editor software,and the extracted data includes pedestrian speed,pedestrian characteristics(gender and age),pedestrian behaviour(rolling behaviour,path change,etc.),vehicle characteristics(type and speed of the vehicle)and traffic characteristics.Pedestrian crossing speed change patterns(whether pedestrian is changing speed or not while crossing a road)was considered as a binary variable and a logistic regression model was developed with vehicular gaps and other pedestrian behavioural characteristics as independent variables.The results revealed that there is a reduction in pedestrian crossing speed change behaviour with an increase in vehicular gap size at unprotected mid-block crosswalks.The younger pedestrians have more probability of exhibiting crossing speed change patterns as compared to the elderly pedestrians at mid-block crosswalks.Further,it is identified that there is an increase in pedestrian crossing speed with increase in vehicle speed as well as heavy vehicle type.Pedestrian behavioural characteristics also have a significant influence on crossing speed.The study findings would provide useful information to designers and policy makers for design of pedestrian crossing facility under mixed traffic conditions.展开更多
为了在保证路段行人过街安全与过街需求的前提下,同时提升路段车辆运行效率,充分考虑了车队离散到达与路段行人过街的动态影响,建立了路段行人过街感应式信号控制方法。首先,基于Robertson车队离散模型,以车头时距对上游到达车队进行动...为了在保证路段行人过街安全与过街需求的前提下,同时提升路段车辆运行效率,充分考虑了车队离散到达与路段行人过街的动态影响,建立了路段行人过街感应式信号控制方法。首先,基于Robertson车队离散模型,以车头时距对上游到达车队进行动态划分,并根据路段行人过街点位预测下游车辆排队状态;以车队离散度选择下游到达车队中车辆作为信号优化输入参数建立感应控制方法,同时分析了路段行人过街位置对配时方案的影响;然后,通过SUMO软件的交通控制接口(traffic control interface,TraCI)搭建仿真环境,以车辆与行人的综合平均延误,分别对路段单向与双向交通环境的信号配时方案进行仿真验证与对比分析。结果表明,相比传统感应控制而言,优化后的感应控制在单向交通与双向交通情况下,行人与车辆综合平均延误分别降低5.56%、7.06%。展开更多
文摘Signalized intersections sometimes involve multistage pedestrian crossings, in which pedestrians cross to one or more islands and then wait there for a signal to continue. When signals are timed without attention to pedestrian progression, pedestrian delay at multistage crossings can be very long. This paper addresses two issues. First, pedestrian delay at multistage crossings is rarely evaluated because there are no tools in the industry for that purpose except microsimulation. We present a numerical method for determining crossing delay with any number of stages and with the possibility of multiple WALK intervals per cycle. The same method can be applied to single stage crossings, to diagonal two-stage crossings where pedestrians may have path choice, and bicycle two-stage turns. This method has been implemented in a freely available online tool. Second, we describe several signal timing techniques for improving pedestrian and bicyclist progression, and thus reducing their delay, through multistage crossings. They include reservice for selected crossing phases, left turn overlaps, having pedestrian phases overlap each other, and bidirectional bicycle crossings which create path options for two-stage turns. Examples show the potential for large reductions in pedestrian delay, often with little or no increase in vehicular delay. In one example, the addition of a short pedestrian overlap phase reduced average pedestrian delay at a 3-stage crossing by 82 s while average vehicular delay increased by only 0.5 s.
基金Supported by the National Natural Science Foundation of China(51278220)
文摘The effects of the interactions between bi-directional pedestrians on the crossing time and the crosswalk width are studied. Firstly,the crossing process of bi-directional pedestrians is analyzed.The total crosswalk time is divided into a discharge time and a crossing time. The interactions between bi-directional pedestrians are quantified with the drag force theory. Then,a model is developed to study the crossing time based on the kinetic energy theory and momentum theory. Subsequently,the related parameters of the proposed model are calibrated with observed information. The relationships among crosswalk width,signal time,pedestrian volume and level of service are simulated with the proposed model. The results are verified and compared with other models. The proposed model has an absolute value of relative error of 9. 38%,which is smaller than that of the Alhajyaseen model（ 15. 26%） and Highway Capacity Manual（ HCM） model（ 12. 42%）. Finally,suggested crosswalk widths at different conditions are successfully estimated with the proposed crossing time model.
文摘The pedestrian crossing speed is one of the important factors in pedestrian crossing facility design.Research studies have shown that the pedestrian crossing speed is influenced by availability of green time at signalized crosswalks and pedestrian characteristics such as gender and age.However,the effects of vehicular time gap and additional pedestrian behavioural characteristics on pedestrian crossing speed patterns have not been examined at unprotected(un-signalized)mid-block crosswalks.The present study examines the pedestrian crossing speed change patterns considering the effect of vehicular time gap and pedestrian behavioural characteristics such as rolling behaviour,path change,etc.,at selected unprotected mid-block crosswalk locations under mixed traffic conditions in India.Video graphic survey has been conducted at eight selected unprotected mid-block crosswalk locations in Mumbai City for two to three hours duration during normal weather conditions.The data was mined using AVS video editor software,and the extracted data includes pedestrian speed,pedestrian characteristics(gender and age),pedestrian behaviour(rolling behaviour,path change,etc.),vehicle characteristics(type and speed of the vehicle)and traffic characteristics.Pedestrian crossing speed change patterns(whether pedestrian is changing speed or not while crossing a road)was considered as a binary variable and a logistic regression model was developed with vehicular gaps and other pedestrian behavioural characteristics as independent variables.The results revealed that there is a reduction in pedestrian crossing speed change behaviour with an increase in vehicular gap size at unprotected mid-block crosswalks.The younger pedestrians have more probability of exhibiting crossing speed change patterns as compared to the elderly pedestrians at mid-block crosswalks.Further,it is identified that there is an increase in pedestrian crossing speed with increase in vehicle speed as well as heavy vehicle type.Pedestrian behavioural characteristics also have a significant influence on crossing speed.The study findings would provide useful information to designers and policy makers for design of pedestrian crossing facility under mixed traffic conditions.
文摘为了在保证路段行人过街安全与过街需求的前提下,同时提升路段车辆运行效率,充分考虑了车队离散到达与路段行人过街的动态影响,建立了路段行人过街感应式信号控制方法。首先,基于Robertson车队离散模型,以车头时距对上游到达车队进行动态划分,并根据路段行人过街点位预测下游车辆排队状态;以车队离散度选择下游到达车队中车辆作为信号优化输入参数建立感应控制方法,同时分析了路段行人过街位置对配时方案的影响;然后,通过SUMO软件的交通控制接口(traffic control interface,TraCI)搭建仿真环境,以车辆与行人的综合平均延误,分别对路段单向与双向交通环境的信号配时方案进行仿真验证与对比分析。结果表明,相比传统感应控制而言,优化后的感应控制在单向交通与双向交通情况下,行人与车辆综合平均延误分别降低5.56%、7.06%。
