The act establishing the NTA made it a body corporate consisting of the City Manager of Dublin City Council, the Chief Executive and a member of the senior management team, and a chairman and six other members appointed by the Minister for Transport.

The NTA has charge of public transport in the Greater Dublin Area, which is defined legally for the first time in the Act.

An advisory council, consisting of local government officials and councillors, representatives of the Garda Síochána, the Irish Congress of Trade Unions and business and community interests, was also established.

In 2011, the NTA oversaw the development of the TFI Leap Card scheme which introduced integrated ticketing in the Greater Dublin Area.

[7] As of 2022, the NTA had partially implemented an infrastructure program, titled BusConnects, with a focus on the bus networks in several cities in Ireland.

In January 2009, the Public Appointments Service advertised the position of chief executive officer of the DTA.

[13] The advertisement noted the government's intention to "assign national responsibility to the DTA for bus market regulation and the procurement of public transport services under public service obligations" and for the DTA to take over the duties of the Commission for Taxi Regulation.

It also provided for the abolition of the Taxi Regulator and the transfer of its functions to the renamed National Transport Authority.