A record 25 million passengers used Dublin Airport last year as new services and an improved economy boosted numbers.
The figure beat the previous record of 23.5 million that was set in 2008.
With Dublin Airport having handled 15pc more passengers last year than it did in 2014, the DAA hopes to be in a position this year to decide on plans for a new runway.
The airport, operated by the DAA, already has planning permission for a new runway, but DAA chief executive Kevin Toland said the semi-state company is continuing to evaluate whether a new planning application should be drafted, and when it should target construction.
Mr Toland declined to say precisely when the new runway might be constructed, but the DAA has previously indicated that it anticipates it could be operational within about five years.
"We're evaluating those plans at the moment," he said. "We'll work our way through all of that to see what's the most efficient and the right time to start."
"We're now starting to see constraints, particularly at peak hours."
The existing planning permission for the new runway was applied for before the introduction of the Planning and Development (Strategic Infrastructure) Act.
That allows planning applications for developments of a strategic economic or social importance to the State to be made directly to An Bord Pleanala.
Dublin Airport also announced yesterday that it plans to hire 180 people this year to cope with its growth. The jobs will primarily be customer-facing roles such as security.
Speaking yesterday at the Airline Economics conference in Dublin, IAG chief executive Willie Walsh said that Dublin Airport needs to invest in additional infrastructure if it's to continue being an effective hub.
But he cautioned that such development must also be cost effective.
IAG acquired Aer Lingus last year for €1.36bn and is using Dublin as a hub for transatlantic travel, driving passenger volumes from the UK and other European cities through the capital. IAG also owns British Airways, and Spanish carriers Iberia and Vueling.
"It has challenges in terms of taxiways and stands," said Mr Walsh of Dublin Airport. "I think there are things Dublin needs to address in terms of infrastructure today to enable it to be an effective hub.
"There's a good case for a second runway at Dublin. Runway slots at Dublin are all filled during the peak."
He added: "While I think there's a case for a second runway, I there's an important case to be made for improving the existing infrastructure."