cture construction over the forecast period is expected to occur in OECD countries, followed by the Big 5 countries; the latter will account for around one-quarter of total investments. INFRASTRUCTURE TO 2030: TELECOM, LAND TRANSPORT, WATER AND ELECTRICITY - ISBN 92-64-02398-4 - © OECD 2006 1. A CROSS-SECTORAL PERSPECTIVE ON THE DEVELOPMENT OF GLOBAL INFRASTRUCTURES TO 2030 There is some scope for deliberate government policy to influence modal use - and shift more road use to rail - through the diversion of up to 10% of new road construction (i.e. USD 20 billion to USD 30 billion per year) to rail (in addition to the levels of investment already forecast). These could have some attendant (though probably bearable) consequences in terms of deteriorating overall road infrastructure quality and rising road congestion. Also, road and rail connectivity to airports and ports is critical to growing international movements, and there is a risk in many cities for local planning and amenity issues to override national and international interests in improving these connections. Water supplies and treatment The projections for annual investment in water systems through to 2025 point to significantly higher levels of investment requirements than previous studies suggest. In the OECD and Big 5 economies annual expenditures in the range of USD 770 billion are projected up to 2015 and over USD 1 trillion by 2025. Much of this spending in Europe and North America will be on maintenance, repair and replacement rather than on additions to existing networks, since water systems in many of these countries are now very old and in poor condition. It is primarily in the developing world that new construction and expansion of networks will be required: in Africa only some 40% of the population are served with adequate water supplies, and only 80% in Latin America, the Caribbean, Asia and the Pacific. Not least in OECD countries, environmental pressures will continue to grow, as will the expectations of the general public with respect to