The Taoiseach Mr Ahern told the Dáil today that he expects that barrier-free tolling would be in place by August 2008.
He said this would coincide with the completion of of phases 1 and 3 of the M50 upgrade while the completion of all phases of the upgrade would be in 2010.
The controversial €600 million buyout of the West Link toll bridge will be completed inside two weeks, Mr Ahern said.
The purchase means that National Toll Roads (NTR) will hand over the operation of the M50 in 2008 and will be paid €50 million every year until 2020.
" That should have a huge impact on the efficiency on the movement of the 100,000 vehicles that are going across the M50," the Taoiseach told the Dáil.
Defending the scale of the buyout, Mr Ahern said: "This is a sensible way of approaching the situation, it is getting NTR out of the equation."
He added: "It would have been nice if we could have predicted 20 years ago that we would have 7 per cent economic growth for 10 years, but we didn't.
"People were talking about 10,000 vehicles a day, not 100,000 as we have now."
A new company will manage the electronic barrier-free tolling system, which is expected to cost €113 million.
Mr Ahern added that the completion of all the phases of the M50 would have a "big impact" on traffic.
The Taoiseach said that the money from the barrier-free toll would come back into the State and would help fund the M50 upgrade.
Additional reporting PA