Asphalt pavements as the most prevalent transportation infrastructure, are prone to serious traffic safety problems due to functional or structural damage caused by stresses or strains imposed through repeated traffic loads and continuous climatic cycles. The good quality or high serviceability of infrastructure networks is vital to the urbanization and industrial development of nations. In order to maintain good functional pavement performance and extend the service life of asphalt pavements, the long-term performance of pavements under maintenance policies needs to be evaluated and favorable options selected based on the condition of the pavement. A major challenge in evaluating maintenance policies is to produce valid treatments for the outcome assessment under the control of uncertainty of vehicle loads and the disturbance of freeze-thaw cycles in the climatic environment. In this study, a novel causal inference approach combining a classical causal structural model and a potential outcome model framework is proposed to appraise the long-term effects of four preventive maintenance treatments for longitudinal cracking over a 5-year period of upkeep. Three fundamental issues were brought to our attention: 1) detection of causal relationships prior to variables under environmental loading (identification of causal structure); 2) obtaining direct causal effects of treatment on outcomes excluding covariates (identification of causal effects); and 3) sensitivity analysis of causal relationships. The results show that the method can accurately evaluate the effect of preventive maintenance treatments and assess the maintenance time to cater well for the functional performance of different preventive maintenance approaches. This framework could help policymakers to develop appropriate maintenance strategies for pavements.

翻译：沥青路面作为最普遍的交通基础设施，由于重复交通荷载和持续气候循环所施加的应力或应变导致的功能性或结构性损伤，容易引发严重的交通安全问题。基础设施网络的良好质量或高可用性对国家的城市化和工业发展至关重要。为维持良好的路面功能性能并延长沥青路面使用寿命，需要评估养护策略下路面的长期性能，并根据路面状况选择有利方案。评估养护策略的主要挑战在于：在车辆荷载不确定性及气候环境中冻融循环干扰的控制下，为结果评估生成有效的处治措施。本研究提出一种结合经典因果结构模型与潜在结果模型框架的新型因果推断方法，用于评估四种预防性养护措施对纵向裂缝在五年养护期内的长期效果。三个基本问题受到关注：1）环境荷载下变量间因果关系的检测（因果结构识别）；2）排除协变量后获得处治对结果的直接因果效应（因果效应识别）；3）因果关系的敏感性分析。结果表明，该方法能准确评估预防性养护措施的效果，并确定最佳养护时机以适配不同预防性养护方法的功能性能需求。该框架可帮助决策者制定适宜的路面养护策略。