construction has been constrained by limited availability of public finance. Moreover, in most of the so-called Big 5 economies (Brazil, China, India, Indonesia and Russia) and developing countries, there has been chronic underfunding of transport and other infrastructure, also reflecting limited public finance availability. On these assumptions, it seems safe to say that also in future, the benefits of road infrastructure spending will exceed the costs. In comparison with the economic benefits generated by infrastructure, the value of infrastructure as a contributor to higher living standards and quality of life has received much less attention. Yet it is likely to be very high, given that households and private individuals are heavy users of infrastructure systems. Part of the problem is that the value of unpriced goods is difficult to measure. However, broad indicators of infrastructure availability can give a flavour of the difference to living conditions that infrastructures may make. By way of illustration, it is clear that the coverage of 98% of the population in developed countries with sanitation services produces health and welfare outcomes greatly superior to developing regions with an average of only 49% coverage. More concretely, since in some cases health and welfare outcomes can in fact be approximated, it is estimated for the developing regions of the world that the benefits of halving the proportion of people without access to improved water sources by 2015 would be 9 times the costs incurred. Universal access to improved water and sanitation services by 2015 would generate an even higher benefit/cost ratio, in the range of 10. (See the contribution by Ashford and Cashman.) By the same token, raising worldwide electrification rates from 74% in 2002 to 83% in 2030 (as projected by the IEA in the World Energy Outlook, 2004) would provide millions of people with electricity for the first time, contributing hugely to social development through education and public health, satisfying more effectively 