METROLINK passengers are suffering because the tram system is a victim of its own success.

The National Audit Office (NAO) says standards of comfort have got worse over the last ten years because carriages are so overcrowded at peak times.

These findings are revealed in a critical report into light rail systems across the country, which says they have failed to attract enough commuters. The watchdog also says that they are running at a loss, and that costs must come down if private investors are to sink money into new lines: Metrolink is due to massively expand to towns across Greater Manchester.

The NAO also complains that tram systems are not fully integrated with other forms of public transport; they have had little or no impact on reducing road congestion; through-ticketing is inadequate; and there are insufficient park-and-ride schemes.

However, Manchester's Metrolink escaped relatively lightly compared to its counterparts in Sheffield, Midland, Croydon and Tyne and Wear which the NAO also analysed.

Metrolink was the only system to have exceeded passenger projection figures, by five per cent to 19 million. This contrasts with a 45 per cent shortfall in Sheffield, the kind of slump which is putting off investors. But locally, this has led to overcrowding and a drop in its comfort rating.

Figures for 2002 show that Metrolink was running at a loss of £5.5 million: however, it was the only system of those compared to make an operating profit, before interest charges were taken out.

The NAO says the Government should work with the industry to reduce building costs through greater standardisation in the design and construction of vehicles. It calls for more integration, park-and-ride schemes, and improved speed and punctuality.