Taoiseach Bertie Ahern defended Operation Freeflow in the face of strong criticism from Socialist Party TD Joe Higgins.
Mr Higgins claimed its introduction, on Monday, had done nothing to ease traffic congestion in Dublin, and called for the provision of extra buses and trains "before our people have a collective breakdown induced by gridlock".
Mr Ahern said there were about 800,000 more vehicles on the roads compared to some years ago. The Government had approved funding of €30 million for the purchase, by Dublin Bus, of 100 additional buses.
"A large number of them will arrive in January, which is in the short-term. There will be a further upgrading of the garage facilities at Broadstone, as well as the new station at the airport, both of which will affect the deputy's (Dublin West) constituency."
Mr Ahern said there was also the proposed Dublin Transport Authority procurement of about 100 buses from the private sector to provide services on new routes, many of which would serve the new estates of west Dublin.
Mr Higgins claimed that Operation Freeflow had been scarcely noticed by hard-pressed commuters, whether travelling on private or public transport.
"It was more a question of operation no-go as usual. People neither arrived earlier to work or home to their families." Yesterday morning, he added, it had taken 30 minutes to get from Mulhuddart to the Blanchardstown roundabout, "a grand distance" of one and a half miles.
"Had the most famous stable in history been sited on the Blanchardstown roundabout, Mary and Joseph would have got quicker from Mulhuddart on their ass this morning than their unfortunate fellow travellers, all of 2,000 years later, and would have breathed fresh air all the way.
"Had they tried public transport this morning, they would have found as little room there as they did in the historic inn. In short, it is a disaster, and what is true of Blanchardstown is true of the greater Dublin area," he said.
