Gridlock is costing the CIE €80 million a year according to the National Bus and Rail Union (NBRU).
The union claimed the Government's lack of transport policy to wean drivers away from their cars meant the gridlock was set to continue.
Liam Tobin, General Secretary of the NRBU told delegates at the union's annual conference in Donegal Town that people were driving an average of 16,000 kilometres a year to work, compared with 8,000 kilometres a decade ago.
Mr Tobín also criticised the Government for not fully integrating a public transport smart card.
He said: "It was 1999 when the then Minister for Transport, Mary O'Rourke, announced that a smart card for integrated ticketing would be introduced. Seven years and €42 million later the smart card is still only valid for Luas and a couple of private bus operators."
"This fiasco is on a par with the electronic voting machines, except in this case hundreds of thousands of commuters are affected every day, not just once every five years when an election takes place. Whatever else it is this integrated ticketing system is certainly not smart."
