Coping with delays is an ever-present challenge for construction projects throughout the world, and both practitioners and researchers have focused their attention on ways to prevent them or to mitigate their effects. Civil engineering projects in Libya, too, especially projects involving road construction, constantly face construction delays. This study proposes a conceptual model of delay factors and provides an analysis of the level of impact of identified delay categories on the completion of the road construction projects. Data for the study were obtained from 256 valid responses to questionnaires and analysed using the Statistical Package for Social Sciences (SPSS) software. Thirty-nine delay causes that influence delay in road projects were identified and classified into 8 core groups of factors in the final conceptual model. The five most significant factors affecting the completion of the project are: (US1) Delays in the conversion and transfer of utility services by the competent authorities (such as power lines, water, etc.) (mean = 4.03); (OW1) Difficulty in Budget availability for the project (mean = 4.02); (PR1) Original contract duration is too short (mean = 3.96); (OW4) Delay in progress payments by the owner (mean = 3.96); (US4) Effects of subsurface (underground) conditions (mean = 3.89). Since the contractor has the most significant impact on the delay in road projects, control of the delay is influenced by the group of factors pertaining to the contractor. Parties involved in government construction projects can benefit from the findings of the study, which can help them find suitable solutions to resolve delays.