“Density Form and Transportation.” Inspired by ‘What is Lost Space’ (Roger Trancik, 1986) This essay will explain how the city forms and how the constraint such as transportation development configured the city form. City is a n arrangement of various forms and functions of buildings. ‘A city is a relatively large and permanent settlement’. Referring to the explanation above, there are several elements that make up a city. The city's development started from the hierarchy of logical rehabilitation stages. Human has natural behaviour . Natural behaviour creates social life. Social life creates activity . Activity creates function system . Function system creates buildings and roads, and finally buildings, and roads build a city. This theory called the functional city’. In an effort towards functional city, another problem has arisen, creation of lost space ’. According to Roger Trancik in his book, finding lost space: