Rehabilitation of Onitsha-Enugu Dual Carriageway in Anambra State, Nigeria: Lessons Learned

Abstract

The rehabilitation of Onitsha-Enugu dual carriageway in Anambra State, Nigeria, which started in 2009 was marred by inadequate rehabilitation design and gross shortfall in earthwork quantities. The project was awarded at a cost less than 60% of what was actually needed to execute it at the time of award. Delays in the approval of the supplementary bills for the project introduced another (time dependent) variation, i.e. increase in the cost of materials and labour. The fact of the matter   was that rehabilitation design and preparation of the bill of engineering measurement and evaluation were done six years before the contract was awarded. Appraisal of the design specifications shows that the adopted pavement cross section was adequate. The design however, considered a greater percentage of the carriageway to be in good condition, whereas pavement evaluation carried out at the commencement of the project showed that many sections of the carriageway had failed completely. In this study, both the technical deficiencies of the rehabilitation design and the managerial problems militating against timely execution of this road rehabilitation project were identified. Various alternative proposals to execute the contract within and outside the original project cost limit were discussed and recommendations were made based on lessons learned.