The early development pattern of Sài Gòn was influenced primarily by means of transportation. The native population built the earliest settlements along the river banks where trade was facilitated by boat and barge shipping. The Vietnamese further developed the marine transportation system in the late 1700s by digging canals into the interior from the rivers to bring commerce into the central area of Sài Gòn and link to the important Chinese commercial market of Chợ lớn southwest of downtown Saigon. What are now the major wide streets of downtown Sài Gòn were additional wide canals built by the French in the early 1800s.
The canals later lost value after the French built railroads and tramways leading further inland from the rivers and to the north and south of the country. The central canals became recognised as a health hazard, and were filled in during the late 1800s to become the major streets. The two major canals remaining through the city continue to fulfil an important function in absorbing tidal flooding from the Sài Gòn River.
The current road pattern in the inner-city districts of Hồ Chí Minh City was established by the French to link important military and commercial facilities. The major road crossings featured large roundabouts with significant sculptural monuments.
As is typical of most cities, development spread linearly along the roads, leaving agricultural lands in-between the roads, that were later developed for residential use. The first beltway road was built by the Americans in 1971 and 72 around the north and west of the city to divert north-south commercial traffic from the inner-city. The beltway was constructed through agricultural lands with no other development within sight.
Nowadays, the beltway is surrounded by commercial and residential development, and it allowed development of new districts of the city beyond the beltway, extending to Cù Chi.
Residential development followed the patterns of the past and the remainder of the country in terms of narrow small lot sizes, featuring an average of only 4 meters of street or lane frontage. The change over time has been an increase in height and density through the constant renewal in the neighborhoods. Since the American War years, the average height of residential structures has increased from 2 to 3 stories to 4 to 5 stories in the inner city districts. Commercial and residential high-rise buildings spread around the inner and outer city districts along major commercial streets have arisen partly because the city has been unable to make up its mind about what to build downtown. These commercial buildings have been negotiated with the district authorities based upon what is the most that can be built on a given site for a reasonable cost. There has been a general zoning criteria of a limit of 8 stories in most areas and 12 stories at major intersections.
The French and American wars transplanted many rural people to squatter neighborhoods at the edges of the inner city. In the war years from 1950 to 1975, the city population swelled from a half-million to over two million people. Since the wars, rural people have continued to flood into the city in search of jobs and opportunities. The Phú Nhuận district neighborhood between downtown and the airport, for example, was full of squatter shacks that appropriated small pieces of land along access lanes that were unplanned and were established as new families moved in. That is why the lanes between the major streets have no rational pattern.
Then over time, the initial flimsy shacks were replaced with one-story masonry houses of the same land size. Then a few years later, these small houses were replaced with two-story structures as families grew. More recently, these structures are being replaced by five-story structures. There is constant renewal like this in all of the neighborhoods, and this is a major engine of economic growth of the city.
As the Vietnamese experienced their version of the baby-boom after the wars, population projections have indicated and proven an exponential rise in population. The planning authorities of Hồ Chí Minh City have therefore instituted master plans for several new urban areas, beginning with the Saigon South area around 2000 to accommodate a million habitants. The Phú Mỷ Hưng area is the first major suburb in the Saigon South area. Subsequently, the city has planned for a new central business district to be constructed on wetlands across the Sài Gòn River, called Thủ Thiêm. Other new urban areas include the Northwest Metropolitan area around Cù Chi, and relatively unplanned expansion is occurring in the urban districts east of Thủ Thiêm due to the construction of new highways to serve a planned new international airport as well as busy port facilities along the Dồng Nai River.
Some of the most successful expansions of development in Hồ Chí Minh City have been urban infill. Until the 1990s, there was a large wetlands area north of the Thị Nghè canal between the Phú Nhuận and Bình Thạnh Districts.
Since the area was surrounded by the city and became highly polluted, the area was drained and filled in to provide a large new urban area that has now been fully developed into one of the most vibrant inner-city neighbourhoods along Phan Xích Long street, which itself was created by a large storm-drainage project in 1972.
The next generator of urban growth and form will be along the transit corridors created by a new metro subway system currently being planned.