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
When arranging the pedestrian infrastructure,one of the most important components that make a tangible contribution to the safety of pedestrians is to organize the safe road crossing.In cities,pedestrians often cross ...When arranging the pedestrian infrastructure,one of the most important components that make a tangible contribution to the safety of pedestrians is to organize the safe road crossing.In cities,pedestrians often cross a road in the wrong place due to established routes or inadequate location of crosswalks.Accidents with the participation of pedestrians who crossed the road neglecting the traffic rules,make up a significant part of the total amount of road accidents.In this paper,we propose a method that allows us,on the basis of the results of a computer simulation of pedestrian traffic,to obtain predicted routes for road crossing and to indicate optimal locations for crosswalks that take into account established pedestrian routes and increase their safety.The work describes an extension for the existing AntRoadPlanner simulation algorithm,which searches for and clusters points where pedestrians cross the roadway and suggests locations for new crosswalks.This method was tested on the basis of a comparative simulation of several territories before and after its application,as well as on the basis of a field study of the territories.The developed algorithm can also be used to search for other potentially dangerous places for pedestrians on plans of districts,for example,crossings in places with limited visibility.展开更多
The drivers’yielding distance to pedestrians at midblock crosswalks affects pedestrians’perceived safety.This distance can be influenced by either crosswalk-related or noncrosswalk.In most cases,crosswalk-related fe...The drivers’yielding distance to pedestrians at midblock crosswalks affects pedestrians’perceived safety.This distance can be influenced by either crosswalk-related or noncrosswalk.In most cases,crosswalk-related features are readily available or easy to collect compared to non-crosswalk features.However,the extent to which crosswalk-related features affect the spatial yielding compliance is not clear.This study evaluated the role of combined crosswalk-related features on drivers’spatial yielding compliance at signalized midblock crosswalks.The study used observational survey data collected from fifteen flash-based signalized midblock crosswalks located in Las Vegas,Nevada.Three logistic regression models,with crosswalk-related features only,non-crosswalk features only,and combined features,were developed and compared.It was revealed that the performance difference between the model with crosswalk-related features only and combined features was insignificant.This study found that the presence of state’s law signs,“PED XING”signs,and placement of rectangular rapid flashing beacons(RRFBs)on the advanced pedestrians crossing signs(APCSs),are significant factors for high spatial yielding compliance.On the contrary,the yield line’s presence at a distance greater than 40 ft from the crosswalk,presence of one stage crossing,and high Annual Average Daily Traffic(AADT)negatively affects the spatial yielding compliance.Moreover,the findings suggest that researchers should be careful about excluding the non-crosswalk features from the analysis.To improve spatial yielding compliance,several recommendations that the city planners and engineers can adopt are provided.展开更多
OCLC的自动元数据映射服务(Godby,Smith and Childress,2008)一文规范了"映射"的概念。如Gill等所定义的,隐藏起具体的技术细节,而以语义元素的对等关系作为中心内容。这样做可以让元数据专家(他们通常并不是程序员)负责建立...OCLC的自动元数据映射服务(Godby,Smith and Childress,2008)一文规范了"映射"的概念。如Gill等所定义的,隐藏起具体的技术细节,而以语义元素的对等关系作为中心内容。这样做可以让元数据专家(他们通常并不是程序员)负责建立映射所需的逻辑关系电子表格,程序据此自动将其转换成可执行的代码。论述DC-Term(限定版DC)应用纲要与MARC映射的管理及实现方法。对应用纲要进行编码时,映射方案需要在对照表的基础上增加两项内容:一是标注元素所属的命名域,二是标注"上位元素"和"下位元素"的关系,例如DC的Cov-erage(范围)元素和Spatial(空间)元素就存在这种关系。这些信息可以供"OCLC语义对等描述语言(Semantic E-quivalence Expression Language,SEEL)"生成脚本文件,用于"元数据自动映射Web服务"进行"生产级"的元数据翻译工作。由于这样只需要关注元素,元素可以混搭、匹配、增添和再定义,因此元数据"应用纲要"(Heery andPatel,2000)非常适合采用这个翻译模型,通过成对元素之间的映射,实现元数据方案的互操作。展开更多
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.
基金This work was financially supported by Russian Science Foundation with co-financing of Bank Saint Petersburg[Agreement#17-71-30029].
文摘When arranging the pedestrian infrastructure,one of the most important components that make a tangible contribution to the safety of pedestrians is to organize the safe road crossing.In cities,pedestrians often cross a road in the wrong place due to established routes or inadequate location of crosswalks.Accidents with the participation of pedestrians who crossed the road neglecting the traffic rules,make up a significant part of the total amount of road accidents.In this paper,we propose a method that allows us,on the basis of the results of a computer simulation of pedestrian traffic,to obtain predicted routes for road crossing and to indicate optimal locations for crosswalks that take into account established pedestrian routes and increase their safety.The work describes an extension for the existing AntRoadPlanner simulation algorithm,which searches for and clusters points where pedestrians cross the roadway and suggests locations for new crosswalks.This method was tested on the basis of a comparative simulation of several territories before and after its application,as well as on the basis of a field study of the territories.The developed algorithm can also be used to search for other potentially dangerous places for pedestrians on plans of districts,for example,crossings in places with limited visibility.
基金the Department of Civil and Environmental Engineering and Construction at the University of Nevada,Las Vegas,for the financial and material support
文摘The drivers’yielding distance to pedestrians at midblock crosswalks affects pedestrians’perceived safety.This distance can be influenced by either crosswalk-related or noncrosswalk.In most cases,crosswalk-related features are readily available or easy to collect compared to non-crosswalk features.However,the extent to which crosswalk-related features affect the spatial yielding compliance is not clear.This study evaluated the role of combined crosswalk-related features on drivers’spatial yielding compliance at signalized midblock crosswalks.The study used observational survey data collected from fifteen flash-based signalized midblock crosswalks located in Las Vegas,Nevada.Three logistic regression models,with crosswalk-related features only,non-crosswalk features only,and combined features,were developed and compared.It was revealed that the performance difference between the model with crosswalk-related features only and combined features was insignificant.This study found that the presence of state’s law signs,“PED XING”signs,and placement of rectangular rapid flashing beacons(RRFBs)on the advanced pedestrians crossing signs(APCSs),are significant factors for high spatial yielding compliance.On the contrary,the yield line’s presence at a distance greater than 40 ft from the crosswalk,presence of one stage crossing,and high Annual Average Daily Traffic(AADT)negatively affects the spatial yielding compliance.Moreover,the findings suggest that researchers should be careful about excluding the non-crosswalk features from the analysis.To improve spatial yielding compliance,several recommendations that the city planners and engineers can adopt are provided.
