The transportation sector, responsible for over one-fifth of global carbon emissions, requires significant technological transitions to align with global climate goals. This study uses a global integrated assessment model (GCAM) to evaluate deep decarbonization scenarios for the transportation sector, aiming to limit end-of-century warming to 1.5°C. The scenarios consider varied timelines for fossil fuel phase-out and the implementation of advanced alternative technologies. Electrification is found to be the most effective low-carbon technology across all modes, with biofuels and hydrogen being crucial for aviation and shipping. The most ambitious scenario eliminates transportation emissions by mid-century, significantly contributing to climate targets but requiring rapid technological shifts and integrated impacts on fuel demands and availability. The study highlights the importance of coordinated efforts across sectors and environmental systems to achieve deep decarbonization in the transportation sector, emphasizing the need for emerging low-carbon technologies and policy support.The transportation sector, responsible for over one-fifth of global carbon emissions, requires significant technological transitions to align with global climate goals. This study uses a global integrated assessment model (GCAM) to evaluate deep decarbonization scenarios for the transportation sector, aiming to limit end-of-century warming to 1.5°C. The scenarios consider varied timelines for fossil fuel phase-out and the implementation of advanced alternative technologies. Electrification is found to be the most effective low-carbon technology across all modes, with biofuels and hydrogen being crucial for aviation and shipping. The most ambitious scenario eliminates transportation emissions by mid-century, significantly contributing to climate targets but requiring rapid technological shifts and integrated impacts on fuel demands and availability. The study highlights the importance of coordinated efforts across sectors and environmental systems to achieve deep decarbonization in the transportation sector, emphasizing the need for emerging low-carbon technologies and policy support.