The cost covers materials and labour for broken windows, damage to seating and seat belts and damage caused by paint bombs and graffiti – for Ulsterbus, Citybus, Flexibus and Northern Ireland Railways (NIR).

The total figure of £3,958,356 million, obtained under the Freedom of Information Act, does not include losses incurred by buses maliciously damaged beyond repair and written off.

William Irwin, a member of the Stormont committee scrutinising and advising on transport, said: "It's a staggering amount of money – society needs to get its act together on this.

"I understand it's a difficult problem for Translink but more needs to be done," the Newry and Armagh DUP MLA said.

Mr Irwin said additional CCTV cameras to help prosecute those responsible should be considered.

The cost of damage to the public transport industry has fluctuated over the five-year period.

This year to date the cost of senseless damage has risen to more than £830,000.

Last year the total was £805,027 with the cost in 2006 calculated at £862,958.

The figure was around £720,000 each year from 2003 to 2005.

Translink said it has a reward scheme – applied to buses and NIR since 2001 – that will make a cash payment of up to £1,000 to any member of the public who witnesses any incident of trespass, vandalism or assault against a member of staff and is prepared to give evidence in court, resulting in a conviction.

A Translink spokeswoman said: "Translink condemns all acts of vandalism against our vehicles and property and we would encourage individuals to report incidents either to Translink or Crimestoppers, as we can also prosecute under some transport legislation.

"We appeal to the public to act responsibly when using public transport as the health and safety of all our passengers and staff is of paramount importance at all times," she added.

Last week Translink said it had erected signs warning of anti-social behaviour at every bus and train station in Northern Ireland.