The first area of inquiry was transportation technology and city building process was studied by urban sociologists. They observed that by 1900 a ‘revolution in transportation’ had permitted a vast out migration of households to occur. Executives of the trolley companies had coalesced with the home- builders and politicians to service the aspirations of millions of city dwellers and politicians to cater to the aspirations for a house and a plot of land near urban periphery. It was a system that benefited only those in the upper scale of income. The city centers that the upper classes left behind were not well served by technology or impressive organizational innovations. Some studies were also done on technological systems such as sewers and water supplies as well as the telecommunication, evolving the field of public work. The later work primarily focused on transportation. How automobile changed the social and spatial equations in the city.

The second area of inquiry after 1970 was the area of public policy. Prime example was the streetcar. It was becoming clear that amenities such as clean drinking water, fire protection, and street-lighting were the ambition of the civilization and their installation and regular delivery was as much a social and political accomplishment as a technological triumph. It was also pointed out that the urban transportation problem was a problem of transportation policy.

Technologies of communication are changing fast and so are material and energy. They will stimulate changes in urban form and social patterns. With changing technology and business such as in Pittsburg telecommunication and international network and operative, the decline of the central business has been reversed. So far as energy is concerned we will study the example of the invention of the chimney and fireplace.