In the United Kingdom the impact of recently joining the Common Market has been considerable. The requirement to follow Common Market Directives has produced a situation where the new harmonized laws will eventually supersede the old. The new directives which will take some years to become fully effective are aimed at eliminating the barriers affecting the operation of commercial vehicles which have divided Europe in the past and the inauguration and implementation of a common transport policy. Widely different regulations are viewed as very serious barriers in trade in Europe and, indeed, on a worldwide scale they are becoming very serious barriers to international trade.The difference between the rule-making procedure in Europe and the United States is explained, and the interesting and important differences between the European Type Approval system as compared with the American self-certification procedure are discussed in some detail. Recognition of the parameters involved in the formation of the European organizing bodies is explained and an interpretation of the relative importance of each organization is presented. The current list of Common Market Directives affecting truck design is explained with some comment on the reasoning behind them. This is followed by reference to future technical regulation activity and the direction and trend of various important factors such as lighting and signaling, weights, dimensions, and performance criteria which will affect the future operation in the longer term of all European commercial vehicles. The future classification method of rating vehicles is given, and detailed reference is made to environmental trends on safety and exhaust emission.