The transportation industry is a significant contributor to global greenhouse gas emissions, accounting for roughly 24% of global energy-related emissions. Various strategies have been employed worldwide to reduce these emissions, including the adoption of public transportation systems, shared mobility solutions, electrified transportation, and intelligent transportation applications. This paper explores case studies within these categories, analyzing the measures taken and evaluating their effectiveness in reducing carbon emissions. The findings highlight the importance of technological integration, policy support, and innovative approaches in achieving significant emission reductions and moving towards a sustainable transportation future.