Explaining and comparing delay patterns in urban construction projects across government and non-government sectors in Tabriz

Abstract

Construction project delays remain a critical challenge in urban developent, particularly in contexts characterized by financial constraints, institutional complexity, and fragmented stakeholder responsibilities. This study investigates the key causes of delays in urban construction projects through a comparative analysis of government projects (GPs) and non-government projects (NGPs) in Tabriz, Iran. A quantitative survey-based approach was adopted, and data were collected from experienced construction professionals using a structured questionnaire developed through a systematic review of the literature and expert validation. Statistical analyses, including descriptive statistics, the Friedman test, and the Mann–Whitney U test, were employed to examine the relative importance of delay factors across five dimensions: laws and regulations factors, client-related factors, consultant-related factors, contractor-related factors, and city-specific conditions. The results indicate that government projects experience more severe delays, primarily driven by regulatory constraints, contractor financial limitations, and procurement practices, whereas non-government projects are more sensitive to financial instability and execution management issues. Across both sectors, weak stakeholder coordination and deficiencies in planning and control systems were identified as common delay drivers. The study contributes to the construction management literature by providing a within-city comparative analysis under a shared institutional environment, enabling a clearer understanding of how governance structures shape delay patterns across sectors. The findings offer practical implications for improving contract management, regulatory clarity, stakeholder coordination, and overall project schedule performance in urban construction projects.