A New Methodology for Before–After Safety Assessment Using Survival Analysis and Longitudinal Data

The widely used empirical Bayes (EB) and full Bayes (FB) methods for before–after safety assessment are sometimes limited because of the extensive data needs from additional reference sites. To address this issue, this study proposes a novel before–after safety evaluation methodology based on survival analysis and longitudinal data as an alternative to the EB/FB method. A Bayesian survival analysis (SARE) model with a random effect term to address the unobserved heterogeneity across sites is developed. The proposed survival analysis method is validated through a simulation study before its application. Subsequently, the SARE model is developed in a case study to evaluate the safety effectiveness of a recent red‐light‐running photo enforcement program in New Jersey. As demonstrated in the simulation and the case study, the survival analysis can provide valid estimates using only data from treated sites, and thus its results will not be affected by the selection of defective or insufficient reference sites. In addition, the proposed approach can take into account the censored data generated due to the transition from the before period to the after period, which has not been previously explored in the literature. Using individual crashes as units of analysis, survival analysis can incorporate longitudinal covariates such as the traffic volume and weather variation, and thus can explicitly account for the potential temporal heterogeneity.     

重庆经济现状及发展战略之管见

重庆作为共和国最年轻的一个直辖市,其经济发展具有工业基础、科技力量雄厚等优势,同时存在农村经济落后等困难;重庆经济发展战略主要是大城市带动大农村战略、开发性移民战略、区域经济和流域经济战略.     

长江三角洲南部下蜀黄土与硬粘土层关系初探

从气候变化和地形影响两个角度 ,对长江三角洲南部晚更新世地层中西部丘陵区的下蜀黄土与东部平原区的硬粘土层进行了初步探讨 ,认为二者的物质来源都是末次冰期盛冰期由风力搬运堆积而形成的。     

关于有限群的可解性

利用极大子群的几乎正规的概念得到了有限群为可解群的若干充要条件．     

韩非子思想矛盾性浅析

韩非子是法家的集大成者 ,但其思想是矛盾的 ,这种矛盾同他的王室地位和先秦时期的夸饰风气有着密切的关系。这种矛盾并不影响其人格的评价。韩非子是个爱国者 ,其人格是伟大的。     

数控机床虚拟实验系统的研究

文章以数控车床实验为对象,介绍了虚拟实验系统的设计思想,并开发出基于980T数控系统的虚拟实验系统.     

中国早期共产主义者对党建思想的探索

早期共产主义者学习和利用马列主义政党学说的基本原理来解决在中国建立政党的过程中遇到的具体问题,提出为什么要建立政党、如何建立和建设政党等党建根本问题。     

明清时期长江中下游地区的土地利用

我国明清时期长江中下游地区的土地利用状况是自汉、唐以来人地关系日益尖锐的结果。文章在分析了当时土地利用方式的基础上 ,进一步对形成土地集约化经营趋势日趋明显的原因进行了论述 ,并从明清时期的土地利用得出启示 :我国土地资源的开发利用必须走可持续发展之路     

常德市旅游、商贸宣传品的英译探讨

要达到对外宣传预期的目的 ,旅游、商贸对外宣传品的翻译必须正确、得体、一致。实例表明 ,常德市旅游、商贸对外宣传品的翻译在这些方面普遍存在问题。因此 ,要提高翻译质量 ,除管理者高度重视外 ,译者要加强英、汉语功底的修养 ,培养敬业精神