Slower, smaller and lighter urban cars

Rising global car ownership levels generate a variety of problems, including traffic congestion, oil depletion, air pollution and traffic accidents. These problems are usually most severe in urban areas. This paper examines the potential for large reductions in maximum speed, size and mass of urban cars to ameliorate these problems. It is found that cutting maximum speeds would significantly lower the frequency and severity of traffic accidents, especially in the third world, where fatality rates per vehicle are very high. If cars carried a maximum of two to four persons, car length and width could be reduced. Such cars would require smaller lane widths and less parking space, thus helping to ease traffic congestion. The combination of smaller and slower vehicles means that car mass can also be greatly reduced, which in turn reduces fuel use and, with it, urban air pollution and carbon dioxide emissions.