The removal of fuel subsidies in Nigeria in May 2023 created an unprecedented economic imperative for Compressed Natural Gas (CNG) adoption, yet the factors influencing adoption decisions among commercial transport operators and commuters remain poorly understood. This study examines the socio-economic, technical, and operational determinants influencing CNG adoption among taxi and mass transit operators and commuters in Abuja's Federal Capital Territory. Employing a convergent parallel mixed-methods design, the research surveyed 119 commercial drivers (41 mass transit, 49 conventional taxis, 29 e-hailing vehicles) and 72 commuters across Phase 1, 2, and 3 districts, complemented by 25 key informant interviews and 4 focus group discussions. Binary logistic regression identified access to credit as the strongest predictor of conversion intention (OR 4.535, p=0.001), followed by vehicle ownership status (OR 3.472, p=0.001), education (OR 1.887, p=0.001), and income (OR 1.669, p=0.003). Knowledge assessment revealed critically low awareness (mean score 52.3%), with only 13% possessing high knowledge, while safety protocol knowledge was alarmingly deficient (only 11% know emergency procedures). Operational analysis demonstrated that intended converters drive 36 km more daily (p=0.001, d=0.91) and spend N9,400 more weekly on fuel (p=0.001, d=0.93) than non-intended converters. Commuter analysis revealed that 61.1% are aware of CNG vehicles, with 52.8% preferring CNG vehicles, and perceptions favorable (86.1% perceive less smoke, 80.6% quieter operation). The study concludes that CNG adoption is constrained by an interconnected triad of socio-economic (credit access, vehicle ownership), technical (knowledge deficits, safety concerns), and operational (infrastructure accessibility, fuel expenditure) determinants. Recommendations include radical simplification of financing mechanisms, motor park-based peer-led awareness campaigns, mandatory safety training for commercial drivers, and commuter awareness campaigns to build public demand.