Abstract: This study appraises the relationship between motorized urban transport mode and CO2 emission in the city of Yaoundé using data from the 2020 urban displacement plan. Adopting a behavioral model’s framework, results indicate that: (a) urban motorized transport modes increase CO2 emissions with minibuses/buses having the highest effects and (2) we observe an inverted U-shaped between the number of travels per day-a proxy for distance and CO2 emissions on one hand, and a U-shaped relationship for the joint effect of motorized urban transport and number of travels per day and carbon dioxide emissions on the other hand. As policy suggestion, in order to build sustainable urban cities, the issue of urban transport modes should be at the forefront of policies and especially, government should curb the importation of very old vehicles that do not have technologies that reduce emissions through a malus and bonus framework for less polluting cars.