The Republic will have to cater for almost one million additional people over the next 20 years, as the population grows to 4.5 million, a special National Leaders Forum has been told.

The forum was attended by the Minister for the Environment and about 250 members of interested parties from property developers to transport providers and members of local government.

The forum heard that as the National Spatial Strategy nears its mid-point - it is not planned for delivery until the end of 2001 at the earliest - the issues being considered include where the additional people will live and work and what social facilities - such as education, healthcare and transport - will be required.

Projections for growth in car ownership range from the present 1.2 million to almost 2.1 million by 2016. This presents a major challenge in managing future transport needs, given the fall in use of sustainable public transport, cycling and walking.

Outlining the Government's policy, the Minister for the Environment, Mr Dempsey, said the National Spatial Strategy "is about where we and our children will live, where we will work, where we will shop, where we will educate our people, where we will access services and where we will spend our leisure time".

The future economic and social needs of the State were, he said, to be balanced with the interests of economic growth as well as quality of life.

Representative interests and local authorities are being asked to take an active role in making those choices and shaping the approach to spatial planning. "Spatial Strategy" planning must, within an overall planning framework, seek to influence the future location of different sorts of development. That is the only way we can achieve our goal of more balanced regional development.

A dedicated Spatial Planning Unit has been established within the Department of the Environment to oversee the development of the strategy.

The National Leaders Forum was chaired by Mr Kieran McGowan, formerly chief executive of the IDA; as well as Government policy, it heard detailed presentations from the Department on the analysis done to date.

The preparation of the strategy is being undertaken in four stages and section two is nearing completion.

In stage one, interest groups were consulted to address the overall objectives of the National Spatial Strategy, and the challenges it should address. This first stage concluded with the publication of a report on the projected scope and delivery of the strategy.

In the second stage, which began in June and is now almost complete, current developmental trends in Ireland and possible new scenarios were studied and analysed by relevant experts.

The research was undertaken in 22 projects across five broad areas - The Urban-Rural Structure, The Location of Enterprise, Transport and Regional Dynamics, Power and Communications Needs, and Social Infrastructure.

The detailed outcome of the research and the potential implications it will have will be developed over the coming months and published by late next spring. This will complete stage two of the development of the strategy.

Many of the findings will highlight the choices that need to be made in guiding future planning. These will then be developed with the public through an extensive process of formal consultation (stage three) which will lead to the final strategy itself (stage four).

The population of the state could, subject to a number of variables, increase from 3.6 million in 1986 to 4.5 million by 2020. Three-quarters of population growth can be attributable to natural increase. For example, the number of households in the State is projected to rise by 616,000 over a 20-year period.

The baseline projection means that the share of population in the mid-east (Cos Meath, Wicklow and Kildare) and the four Dublin Council areas could rise from 40 per cent of the national population in 2000 to 43 per cent in 2020. This is a major issue for the strategy and the State generally.

The key period in planning terms will be the next 10 years or so, when the bulk of growth will take place in housing, jobs and population. Surprisingly, the rise in car ownership is not seen as excessive but converging on an international average. In contrast, the use of sustainable modes of transport among workers has fallen from 43.7 per cent in 1986 to 35.9 per cent in 1996, and continues to fall, as evidenced in the 1999 quarterly national Household Survey.

In rural areas, use of sustainable modes is markedly lower and has also declined from a level of 11.3 per cent to 10 per cent. The contrasting trends in car ownership and sustainable transport mode usage are creating clear challenges in how the State's transport needs are evolving.

The 10 Irish towns with the highest level of sustainable transport use tend to be concentrated in the category of rural market towns.