Slower, smaller and lighter urban cars

Rising global car ownership levels generate a variety of problems, includin g traffic congestion, oil depletion, air pollution and traffic accidents. T hese problems are usually most severe in urban areas. This paper examines t he 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 hi gh. 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 park ing space, thus helping to ease traffic congestion. The combination of smal ler and slower vehicles means that car mass can also be greatly reduced, wh ich in turn reduces fuel use and, with it, urban air pollution and carbon d ioxide emissions.