Professional Survey Standards and Quality Management Systems in Infrastructure Projects: A Study of Road Construction in Ogun State

Survey data quality is a foundational determinant of engineering accuracy and contractual compliance in road construction projects, yet systematic quality management in Nigerian construction survey practice remains inconsistently applied. This study examines the conformance of survey operations to professional standards and the effectiveness of quality management systems in three major road construction projects in Ogun State, representing South West Nigeria. Document review, structured interviews with project surveyors, and independent field accuracy tests are conducted across the selected projects. Quality management documentation, including calibration records, control survey reports, as-built survey procedures, and tolerance specifications, is assessed against the Survey Co-ordination Act and international ISO standards. Independent resurveys of sample cross-section profiles and alignment control points using precision GNSS instruments are conducted, and deviation statistics are computed. Results reveal significant variability in quality management rigour between projects, with internationally supervised contracts achieving markedly higher conformance scores than domestically supervised counterparts. Systemic deficiencies include lack of instrument calibration documentation, absence of independent survey checking protocols, and inadequate as-built survey coverage. The study recommends mandatory quality management plans as a procurement requirement for survey services in Federal and State road contracts. Keywords: survey quality management, road construction, professional standards, Ogun State, quality assurance.