The transportation sector remains one of the largest contributors to Malaysia’s carbon emissions, driven primarily by the growth of private vehicles. This study presents a quantitative evaluation of multimodal transport (MMT) interventions aimed at reducing transport-related CO₂ emissions using a decadal dataset (2014–2024) of national vehicle registrations and mode-specific emission factors. The methodological framework comprises two key stages: (1) trend characterization, which identifies emission growth patterns across five vehicle categories, and (2) scenario-based modeling of emission mitigation under three integrated MMT strategies—public transport expansion, non-motorized transport infrastructure, and freight optimization via rail and waterways. Results reveal that private cars and motorcycles are responsible for nearly 90% of sectoral emissions, rising from 19,000 to 23,000 tons over the past decade. Scenario projections demonstrate that systematic MMT adoption could cut emissions by 6–58% by 2030, with non-motorized transport (NMT) yielding the most substantial reductions. The study underscores the strategic role of policy incentives, urban planning integration, and intermodal coordination in realizing Malaysia’s carbon neutrality objectives. These findings offer a data-driven foundation for sustainable mobility policies and urban emission reduction planning within Southeast Asian contexts.