Consultants’ Ethical Dilemmas and Project Performance: Evidence from Paved Trunk Roads in Dar es Salaam and Tabora Regions of Tanzania

Paved trunk road projects in Tanzania, notably in Dar-es-Salaam and Tabora, frequently encounter delays, cost overruns, and quality deficiencies. Consultants—critical in ensuring design compliance and quality assurance—often face ethical dilemmas arising from institutional weaknesses, conflicting interests, and political or external pressures. This study examines how such dilemmas influence project performance, with a specific focus on political, institutional, behavioural, and socio-economic factors. Employing a cross-sectional design and mixed methods approach, data were collected from 289 respondents, including consultants, contractors, engineers, and public officials. Multiple linear regression analysis was used to assess the relationship between ethical dilemmas and project performance indicators. Findings reveal that institutional and behavioural factors significantly influence ethical dilemmas among consultants. Institutional factors—such as enforcement of codes, transparency, and accountability—exerted the strongest positive impact on project performance (β = 0.857, p < 0.001), underscoring the value of robust governance frameworks. Conversely, behavioural factors—such as greed, lack of integrity, and peer pressure—negatively affected performance (β = -0.221, p < 0.001), highlighting the consequences of personal misconduct. Political factors had a moderate yet significant effect (β = 0.120, p = 0.010). Overall, ethical dilemmas exhibited a negative association with project performance (β = -0.144, p = 0.006), contributing to inefficiencies and quality shortfalls. The findings align with virtue ethics theory, affirming the importance of institutional integrity and moral character. The study recommends strengthening ethical oversight mechanisms and implementing comprehensive institutional reforms to address consultant-related ethical dilemmas and enhance project outcomes.