This paper descriptionbes briefly some aspects of the experimental research on the South African Railways into the conditions affecting the riding quality of railway vehicles. Parameters which influence the vertical riding quality of railway vehicles are given against the theory of forced vibrations. Results recorded during riding quality tests were found to be in good agreement with the theory. A method of simulating vertical oscillations of railway vehicles on a digital computer is outlined.
Urbanisation and the dynamics of metropolitan growth are examined in the context of accelerating technological advance and, more specifically, the modern trend towards interurban rather than urban-rural population movements as well as the internal dispersion of population concentrations. New urban patterns are being created as neighbouring cities and towns are welded together by both economic ties and interstitial urban development to form single functional entities. The influence of industrial development and the changing role of the city centre within this process are discussed.