[citation needed] A further significant upgrade came in 1999 when, in the order to facilitate the opening of the new Jack Lynch Tunnel, a fourth arm heading southbound was added.

Jacobs Engineering was appointed by the NRA to create plans to make the junction free-flow in all movements.

In June 2011, the NRA presented five different solutions to create a free-flow junction,[3] and in 2013, a scheme was approved by the planning board.

[4][5][6] By September 2015, a Capital Investment Plan was unveiled by the Irish government, which secured funding for the interchange.

[8] The upgrade has also involved the installation of digital signage on the approach to the interchange and the N40 to provide information to drivers around journey times and traffic issues.