Urban complexity is expressed through the diversity of uses and activities present in public spaces primarily designed for pedestrians. However, contemporary cities have been designed by prioritizing automobile circulation, allowing them to reach high speeds. This condition affects the sense of security and the free use that pedestrians can make of the street, thereby removing its social role and consequently leading to a loss of urban complexity. Therefore, this study proposes that the speed of automobiles is a variable that influences the loss of complexity in the city. The study will be carried out through data collection in sections of avenues with different levels of vehicle flow. In each of these sections, the average speed of automobiles and buses was recorded to obtain a representative value of traffic speed. In parallel, urban complexity in each avenue was calculated using the formula proposed by Shannon, based on Information Theory, which allows quantifying the diversity of activities and urban actors present. In this way, the collected data was related and analyzed through a scatter plot. It was evidenced that streets with higher speeds have lower diversity and social interaction, while those with lower speeds show greater urban activity. This established an inverse relationship between average vehicular speed and levels of urban complexity. The research provides evidence on how urban complexity is shaped by vehicular speed, thereby contributing to the debate on the design and management of street space from an urban perspective that prioritizes pedestrians.