Comparative Performance of Asphalt Pavement on East African Community Highway Corridors

The East African Community (EAC) highway network constitutes the arterial spine of regional economic integration, connecting landlocked member states to port gateways and enabling intra-regional trade, humanitarian logistics, and population mobility across eight member states spanning diverse climatic and geotechnical environments. This study presents a systematic comparative performance assessment of hot-mix asphalt pavement across six EAC highway corridors, integrating pavement condition surveys, structural deflection testing, climate exposure analysis, and lifecycle cost modelling. Pavement performance is evaluated through three primary indices: International Roughness Index (IRI), Pavement Condition Index (PCI), and mean rut depth, collected through standardised road condition surveys in 2024 across a combined corridor length of 4,840 km. Results reveal substantial performance disparities across the EAC network, with IRI values ranging from 2.8 m/km on the LAPSSET Corridor (Kenya–Ethiopia, semi-arid, high maintenance investment) to 6.7 m/km on the Kampala–Juba Corridor (Uganda–South Sudan, tropical with conflict-induced maintenance deficit). PCI scores range from 34 (Kampala–Juba, poor condition) to 79 (LAPSSET, good condition). Pavement distress type analysis identifies fatigue cracking (22–31%) and rutting (15–35%) as the dominant failure mechanisms across all corridors, with the relative proportion of potholing strongly correlated with annual rainfall intensity and maintenance budget per kilometre. Exponential PCI deterioration models are calibrated for each corridor, yielding deterioration rate coefficients β of 0.028–0.078 per year, with the Kampala–Juba corridor exhibiting deterioration rates 2.8 times higher than the best-performing LAPSSET corridor. A multi-