The Maynooth to Leixlip Project Public Consultation Constraints and Options has now ended. The material that was on display at the public consultation is available here.


Arup has been appointed by Kildare County Council to provide multi-disciplinary technical consultancy services for the delivery of Phases 1 to 4 of the TII Project Management Guidelines for the Maynooth to Leixlip Project, on behalf of Kildare County Council and South Dublin County Council. This appointment includes concept and feasibility studies, options appraisal and selection, design and environmental evaluation and submission of a planning application.

Project Background and Description

The project is included in the National Development Plan 2021-2030 and the draft Greater Dublin Area Transport Strategy 2022-2042. The network forms part of the Trans-European Transport Network (TEN-T) comprehensive network.

The section of M4/N4 corridor under consideration includes the M4 mainline carriageway from Maynooth to Leixlip, the associated mainline junctions and the surrounding transport network.

This section traverses two Local Authority Boundaries, Kildare County Council and South Dublin County Council. Kildare County Council has been appointed as the lead Local Authority and Sponsoring Agency of the project. Kildare National Roads Office (KNRO) has been appointed by Transport Infrastructure Ireland (TII), acting as the Approving Authority, to project manage the delivery of the project.

The existing M4/N4 corridor is predominantly in County Kildare with 1.5km of the approximate 10km length in County Dublin.

The study area is largely greenfield agricultural land punctuated by the urban centres of Maynooth, Celbridge and Leixlip. The Rye Water Valley/Carton SAC (Special Area of Conservation) runs parallel to the line of the M4/N4 along the Rye River from Leixlip to Maynooth. The R157 and R406 allow for the transfer of strategic traffic from the M4/N4 to the M3 and M7 respectfully.

Project Aim

The aim of the project is to assess the needs of the M4/N4 mainline corridor and junctions from Maynooth to Leixlip in terms of operational efficiency and safety. Additionally, it aims to assess alternative transport modes or routes within the study area.

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