SERIOUS concerns over the way the Government is spending millions on infrastructure are expressed today in a new report by a top-level think tank.

Massive cost overruns and delays must be investigated urgently to ensure the same mistakes are not made with the Metro and other major projects, it says.

The review carried out by the transport think-tank, the National Institute for Transport and Logistics, says there is an urgent need for an independent evaluation of the Luas.

The study 'Ireland's Transport System: Towards Sustainability and a Competitive Supply Chain' benchmarked Ireland's transport infrastructure and services across aviation, bus, road and rail services against other UK countries.

It found:

* The prospects for rural public transport are not good.

* Growing concern over the soaring cost of Luas - from an original €288m to around €800m - and the effectiveness of the proposed €2.5bn Metro.

* Little consideration given by the Government to the impact on rail services of spending billions on building new superhighways.

* The public purse faces being drained by handing over vast sums to private operators to build and operate infrastructure under public-private partnership deals.

* The break-up of Aer Rianta raises serious questions about the future viability of Shannon Airport.

While overall Ireland's transport system compared favourably to the UK, concerns were raised about whether the Government was spending billions of euro wisely.

"The large and committed investment in new roads does beg questions over the future of the rail system, particularly inter-urban lines."

Expenditure on new motorways and dual-carriageways to the major cities was running at levels far greater than in the UK, including Northern Ireland and Scotland and Wales.

"However, there is concern about the cost effectiveness of at least some of this expenditure and the rising costs of delivery."

The audit states: "Little consideration has been given to the implications for other modes, notably rail and air services, arising from this unprecedented level of expenditure."

Recent years had seen investment of billions of euros by the Government in transport and this was beginning to produce significant improvements in infrastructure and services.

However, the audit reveals that "serious concerns remain about the return on this investment and whether the Government is receiving value for taxpayers' money".

It adds: "The Luas project was originally costed at €288m but will come in at around €800m and outside the planned completion timeline.

"NITL is of the opinion that there is an urgent requirement for an independent evaluation of the Luas project.

The report also says the proposed break-up of Aer Rianta raises questions about the financial viability of Shannon in particular.

Prof Austin Smyth, director general of the Institute, said: "Substantial sums are currently being invested in Luas but there are questions to be answered about the cost overrun and delivery time.

"An independent assessment is urgently required to evaluate whether the level of outturn expenditure makes the project economically justifiable, why the project took significantly longer to complete than originally envisaged and the lessons for future investment in light-rail or Metro services in Dublin."

The increasing reliance on public-private partnership funding for major infrastructure projects was also identified as another area of potential concern.

In the Greater Dublin Area the quality of public transport is good by the standards of the UK and reasonable on a wider European barometer, the report says.

Inter-urban bus services have developed in recent years, enhanced by improvements to the inter-urban road network.

But rural public transport prospects "are not particularly positive".

In contrast, the Republic's external links performance, notably air transport, far exceeds Northern Ireland and is superior to Scotland and Wales. But the situation is not as good when compared to the rest of Europe.

The wider environmental issue had to be tackled as Ireland was arguably the worst performing EU member under the terms of the Kyoto Protocol.

Prof Smyth said that transport services and infrastructure in the State actually compare favourably with Northern Ireland and the rest of the UK.

- Treacy Hogan Environment Correspondent