The volume of goods transported in Europe and especially the amount of goods transported by road is increasing steadily. The mid-term review of the European Commission's 2001 Transport White Paper predicts that freight transport will increase by 50% and road freight transport by 55% for the period 2000-2020. It is also important to note that the capacity of many European roads has reached, or is close to reaching, saturation point; these roads are experiencing heavy congestion and delays. In view of the fact that congestion and overloaded roads have a serious impact on the local economy and the environment in many areas, road administrations and many other bodies in Europe, face the major challenge of having to combine increased mobility with sustainability. Europe is experiencing a steady increase in the number, weight, and length of the heavy goods vehicles (HGVs) on its roads. Many people feel that the road network is not equipped to accommodate either the increased number of HGVs or their increased size or weight. Two northern European countries, Sweden and Finland, have many years experience in the use of long HGVs on their roads. Both countries are comparatively sparsely populated. Over the years, it has been necessary to make road transport more efficient in order to compensate for the long transport distances travelled. Both the environment and trade and industry have benefited from the efficient road transport networks in these countries. Studies conducted in both Sweden and Finland show the importance of permitting comparatively long and heavy vehicle combinations. A more efficient road freight transport system has a smaller impact on the environment and results in lower traffic density. Although the introduction of longer vehicle combinations may necessitate investment in the road infrastructure, this need should not be overstated. The Netherlands, Denmark, and Norway are currently undertaking or preparing trials involving the so called modular system of 25.25-metre long HGV combinations. In the Netherlands, one of the most densely populated countries in Europe, large-scale trials involving long HGV combinations have been carried out. The trial period has been prolonged. The experiences noted in the Dutch follow-up study are mainly positive. In some European countries, scepticism about long HGVs still prevails while in others, there is outright opposition to the use of longer and heavier HGVs. Some countries are of the opinion that modular HGVs will not help solve the problems associated with the steady increase in inland road freight transportation and are pursuing a strategy of transferring freight transport from the road to the rail network. The purpose of this study is to review the experience gained in Finland and Sweden and to encourage other countries to think about the modular system, which is one of the ways of minimising the negative effects of the ever-increasing growth of freight transport in Europe.