Walking in a pre-car, historic city center feels natural and appealing, but the same cannot be said for contemporary districts designed during the car-centric era. These modern areas often lack landmarks, social activities, and appeal, discouraging pedestrian lifestyles. Literature showcases numerous examples of district rejuvenation efforts aimed at increasing walkability, promoting non-motorized transportation, and fostering healthier, sustainable lifestyles. Walkability serves as a catalyst for urban regeneration, but assessing and quantifying it pose methodological challenges, especially in areas lacking social functions and attractiveness. To address these issues, a methodology is presented and applied to quantify walkability across different urban environments and identify factors that promote it as the primary mode of mobility. The methodology employs a composite index, combining 12 indicators categorized into functions and use, safety, urbanity, and attractiveness. Data for these indicators are collected through direct observation, resulting in a 0 to 1 scale score, with 1 representing excellent walkability. The study tests this methodology in three distinct districts of Rome, each with varying urban characteristics and socioeconomic conditions. Notably, the paper not only quantitatively compares scores among the districts but also highlights an increase in walkability over a decade in the district where a regeneration process took place.