ABSTRACT
Roads are the most valuable public assets worldwide, representing between 15 and 50 percent of countries’ annual Gross National Product. In addition, road transport forms the backbone of any modern transport system with more than 85 percent of all transport going by road. But, despite its enormous importance, roads are often under-financed, poorly managed, and badly maintained. Developing countries, especially, spend on average only between 20 and 50 percent of the amounts necessary to preserve their roads in good condition. Therefore only between 10 and 50 percent of roads in developing countries are in good condition, resulting in huge losses to the economy. Poor road conditions are responsible for higher vehicle operating costs and additional road rehabilitation works, draining the economies annually between 1 and 3 percent of their Gross National Product. But developing countries are not the only ones having road maintenance problems. In the United States, for example, the road maintenance backlog amounts to more than US$200 billion.
