Final answer:
Promoting walking in cities is important for sustainability and livability. It reduces car dependency, traffic congestion, and pollution while improving public health.
Step-by-step explanation:
Promoting walking is important to the development of livable and sustainable cities because it offers numerous benefits. Walking is a sustainable mode of transportation that reduces reliance on cars and decreases traffic congestion and air pollution. Additionally, it promotes physical activity, which improves public health. Urban designers and theorists like X have recognized the importance of walking and have advocated for the creation of pedestrian-friendly spaces within cities.