Tokyo’s population grew dramatically in the twentieth century. The largest urban region in the world has evolved as a series of continuous medium-density suburbs, connected to employment and commercial centres by a very efficient system of underground and railway lines.Nearly four out of five daily journeys in Tokyo are made on the city’s comprehensive public transport network. To accommodate this growth, Tokyo Bay has been progressively infilled to create land for more offices and housing.

The city’s population is spread relatively evenly; it does not have a significant high-density residential inner core. Less than 5% of Tokyo’s total surface is green space. Policies to curb the city’s growth mean that the city is not expected to gain a significant number of residents in the future; its challenge is to produce a more sustainable and pleasant environment for its millions of current residents.

Tokyo’s development has been driven by its disaster-prone environmental landscape. Japan experiences around 27 typhoons per year; Tokyo is prone to earthquakes and floods, a problem exacerbated by the fact that half of central Tokyo is built on low-lying landfill sites. This means the city has always considered its extensive waterfront from the point of view of disaster-prevention, rather than as a recreational asset. This strategy is being reversed as Tokyo addresses its next stage of urban development.