Best practices of sustainable mobility policies are currently shifting from the concept of “predict and provide” to “optimality and sustainability”. Central but simple concept of creating streets as places using the "Link" and "Place" concept, and identifying context-sensitive "Transect" when a person arrives a destination. A detail planning practice while unifying the role of different professionals and providing guidance in developing a more comprehensive two-dimensional street classification is recently developed with the concept of 30 (kmph speed) by 30 (m right-of-way) that has evolved as a street downsizing strategy to align with compact and dense city living ideas. These world class infrastructure ideas are a product of scientific evidence indicating the limiting factors of infrastructure size, particularly intersection and street size that all levels of humans can safely interact. Firstly, traffic engineering solutions keep adding lanes in order to reduce vehicle delays. However, limitations of capacity do exist. Expanding intersections above a certain size has proven an expansive, ineffective and short-lived solution to traffic congestion problems. Secondly, increasing traffic volume, distance travelled, and too many lanes causing an increase in collision frequency, provides evidence of how endless desires for road widening carry the seeds of future decline of the city’s livability. Thirdly, faced with economic, political and environmental challenges, the question of appropriate infrastructure size and design scales that accommodates all segments of demography is critical to the future urban environment. This approach ensures system failure does not occur when future urban living faces unforeseen events such as aging population, extreme weather due to climate change, unused infrastructures due to social and technological changes. In the model, these findings form the basis for maximum size of infrastructures, while assessing future demand that is traditionally ignored. This approach prevents frequent breakdown such as excessive delays, crash-prone potential, environmental degradation and the funding trap of maintenance of oversized “complete street” infrastructures.