Council using traffic calming law to build slip road which increase risk for walking and cycling

South Dublin County Council is using legislation designed for building traffic calming measures to build a new slip road out of a retail park despite design guidance recommending against the use of such designs.

Both use if slip turns is against advised against in the Design Manual For Urban Roads and Streets and the NTA’s National Cycle Manual.

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The Manual For Urban Roads and Streets states that road designers should: “Omitleft turn slips, which generally provide little extra effective vehicular capacity but are highly disruptive for pedestrians and cyclists. Where demand warrants, they maybereplaced with left tuning lanes with tighter corner radii.”

The manual adds: “Left turning slips generally offer little benefit in terms of junction capacity and increase the number of crossings pedestrians must navigate. They also allow vehicles to take corners at higher speeds, exposing pedestrians and cyclists to greater danger. Where a large number of turning movements occur, left turning lanes with tighter corner radii should be used.”

While the planned slip is not at a junction, it is effectively part of the Airton Road road project, the rest of which was approved under the Part 8 planning process.

The traffic calming legislation, Section 38 of the Road Traffic Acts, allows for a wide range of measures, including cycling and bus infrastructure. But the guidance around it is that it is for making changes on existing public roads.

New vehicle access points to private property requires planning permission across the county.

South Dublin County Council said: “As part of the Airton Road Extension construction South Dublin County Council shall construct a new left out turn onto Belgard Road… This new left out turn will reduce the number of cars exiting onto the proposed Airton Road Extension to get onto the Belgard Road.”

It said that the Part 8 for the Proposed Airton Road was approved in April 2022 but that “new owners of Belgard Retail Park have requested that this left out turn onto the Belgard Road is constructed at the same time as the construction of the proposed Airton Road Extension”.

The council added: “This shall include a required temporary plot area (to be confirmed) to facilitate the construction of this new junction. South Dublin County Council will not carry out any reconfiguration works to the Retail Park’s car park. Consultants have been procured to carry out the preliminary/detailed design for the Airton Road Extension. The Consultant is to include in his design the left turn onto the Belgard Road. Both the Airton Road Extension and the left out turn onto the Belgard Road are to be carried out at the same time.”

In a response from the council posted by Cllr Liam Sinclair, Michael McAdam, a senior engineer at South Dublin County Council defended the use of traffic calming legislation for a slip road.

He pointed out that the law defines traffic calming measures as: “measures which restrict or control the speed or movement of, or which prevent, restrict or control access to a public road or roads by mechanically propelled vehicles (whether generally or of a particular class) and measures which facilitate the safe use of public roads by different classes of traffic (including pedestrians and cyclists) and includes the provision of traffic signs, road markings, bollards, posts, poles, chicanes, rumble areas, raised, lowered or modified road surfaces, ramps, speed cushions, speed tables or other similar works or devices, islands or central reservations, roundabouts, modified junctions, works to reduce or modify the width of the roadway and landscaping, planting or other similar works”.

And he also pointed to Part 8 of S.I. No. 600/2001 which lists prescribed types of development to which Section 179 of the Planning and Development Act of 2000 applies. This includes “the construction of a new road or the widening or realignment of an existing road, where the length of the new road or of the widened or realigned portion of the existing road, as the case may be, would be (i) in the case of a road in an urban area, 100 metres or more, or (ii) in the case of a road in any other area, 1 kilometre or more”

McAdam said: “As the proposed road is less than 100m in length and the estimated value of works is less than €126,000, there is no requirement for Part 8 approval. The current Non-Statutory consultation provides people the opportunity to make submissions and suggestions on the proposal.” asked South Dublin County Council to explain why it is using traffic calming legislation for a new exit from the retail park, if it had legal advice that no planning permission is needed, and if there is any agreement with the owners of the retail park and if a copy is available.

McAdam said: “The estimated cost for the exit lane is less than €126,000 and therefore sub-threshold for Part 8 Planning. The use of Section 38 and the associated non-statutory consultation period that SDCC has established, provides an opportunity for interested parties and the public to comment and/or make submissions.”

On the question of legal advice, he repeated part of the previous answer.

On an agreement with the retail park, he said: “While SDCC has been in discussions with the retail park, a final agreement has not yet been reached.”

Public consultation on the slip road is open until July 1 at

Clarification: This article originally also included a section on the funding of the overall Airton Road Extension project, beyond the slip turn. This was removed to avoid confusion and may be covered in another article.

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