Values of Cronbach Alpha for Reliability.

Highway construction projects are known for their propensity to consume enormous quantities of materials and their susceptibility to generate considerable waste. Adequate research has been conducted on identifying the causes of waste produced in building projects, however, there are limited studies available on identifying causative factors for highway projects. This study aims to identify and evaluate the causes and factors of waste generated on highway projects using a literature review and questionnaire survey technique. Causes leading to waste in highway projects were identified from the literature as well as from highway construction experts. Subsequently, quantitative data were collected from 127 highway construction professionals using a Likert Scale questionnaire survey, which was ranked using the Relative Importance Index (RII) and further analyzed by using a very robust Factor Analysis (FA) technique. RII results highlight the most significant causes of waste in highway construction, while FA suggests the main factors contributing to the waste in highway projects. The top five most significant causes of waste revealed by this study were: (1) mistakes of surveyors, (2) faulty drawings, (3) incompetence of quantity surveyors, (4) faulty/substandard work, and (5) poor workers’ skills, whereas the seven waste factor groups evaluated by the study were: (1) design, (2) storage, (3) survey, (4) workers, (5) waste management, (6) site management, and (7) external. This study further suggested waste management and mitigation strategies for highway construction projects corresponding to each factor group. This is a novel study on waste generation in highway projects in Pakistan and will assist academia and industry practitioners in understanding and controlling construction waste generation in highway projects during various stages of project execution.

公路建设工程（Highway construction projects）素来以物料消耗规模庞大、易产生大量废弃物为显著特征。针对建筑工程中废弃物产生的致因，学界已开展充分研究，但针对公路建设工程的相关致因分析却较为匮乏。
本研究旨在通过文献综述与问卷调查法，识别并评估公路建设工程中废弃物产生的各类致因与影响因素。研究首先从公开文献及公路建设领域专家的访谈内容中，梳理得到公路工程废弃物产生的潜在致因；随后采用李克特量表（Likert Scale）设计问卷，向127名公路建设从业人员收集量化数据，并通过相对重要性指数（Relative Importance Index, RII）对问卷结果进行排序，再借助稳健性极强的因子分析（Factor Analysis, FA）技术开展进一步深入分析。
相对重要性指数结果明确了公路建设废弃物产生的最显著致因，而因子分析则提炼出公路工程废弃物产生的核心影响因素组。本研究揭示的前五大核心致因依次为：（1）测量员操作失误；（2）设计图纸存在缺陷；（3）工程量咨询师（quantity surveyors）能力不足；（4）作业质量不合格或未达标准；（5）工人技能水平低下。本研究评估得到的七大废弃物影响因素组分别为：（1）设计类；（2）存储类；（3）测量类；（4）工人类；（5）废弃物管理类；（6）现场管理类；（7）外部类。
本研究还针对各因素组，提出了适配公路建设工程的废弃物管理与减缓策略。本研究针对巴基斯坦公路建设工程的废弃物产生问题开展了创新性探索，将有助于学术界与行业从业者理解并管控项目实施各阶段公路建设工程的废弃物产生情况。