A critical review on alternative fuels for road transportation: Pollution mitigation, environment and economic perspective

Electric, hydrogen, methanol, and biofuel cars are becoming popular for reducing road transport emissions. In limited operational contexts, these technologies are commonly called clean or zero-emission, but resource availability, lifetime implications, and infrastructural restrictions determine their sustainability. Alternative fuels have been explored in India for almost two decades to increase energy efficiency, security, and reduce air and noise pollution. This paper describes and compares significant alternative fuel choices, focusing on India's changing situation and drawing on chosen global lessons. Each fuel type's segment-specific appropriateness, supply chain concerns, legislative frameworks, and environmental impacts are examined. Second-generation feedstocks, including lignocellulosic biomass and non-edible oilseeds, have reduced the food-versus-fuel issue, according to the analysis. Scalability, cost, and technological integration hurdles are thoroughly reviewed. Using current policy advances, market trends, and technological hurdles, this study gives a contextualised path for India's clean mobility aspirations. It helps researchers, policymakers, and industry stakeholders link domestic plans with Paris Agreement climate goals.