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The Dublin Bay Motorway

Eastern Bypass Plan

Boosterstown, Dublin Port Tunnel, Sandyford, UCD, Goatstown
This image shows the areas covered by the proposed motorway, It does not represent the proposed route. © Tripline, Mapbox, Open Streetmap

There has been a long-term plan for completion of the inner ring road (M50 motorway) around Dublin city centre and it has been moving towards an operational stage for the past few years. This long-planned “Inner Orbital” route around the city would necessitate the building of a road or tunnel across Dublin bay at the point of Sandymount-Booterstown. This section has been in the planned inner orbital project has been in the planning stage since 1971.

In 2016, according to Dublin City Council, the Dublin Eastern Bypass full developmental time-table was not yet available.

When completed, the Dublin Eastern Bypass would complete a full ring circle motorway for the city by closing the 11 kilometer gap on the south-eastern side between the Dublin Port Tunnel directly connecting to the M50 at Sandyford. A 2007 feasibility study recommended three possible route options:

1. a viaduct or bored tunnel across the port;

2. a viaduct or tunnel across Sandymount Strand;

3. tunnels and cuttings from there to the N11 and Sandyford. [1]

Date of Completion of Eastern Bypass

As to a possible date of completion of the M50 project, Dublin City Council give a tentative date of 2030, a firm commitment to the project was noted, though a detailed timetable was not available in 2016. However, 2030 is given as a completion date rather than 2035, which is interesting, as it indicates that the there is an expectation present in Governmental Departments that a somewhat faster implementation of the project is on the cards than might appear from the glacial pace of the planning and developmental process to date.

‘The Eastern Bypass’ History:In 1971, The ‘Dublin Transportation Study’ recommended an orbital motorway to encircle Dublin. From the Port Tunnel onwards, one section of the M50 motorway would run either through a tunnel or alternatively, a bridge across Dublin Bay. This section was named the ‘Eastern Bypass.’ The M50 motorway runs from Dublin airport and South to Cherrywood, with the Port Tunnel forming part of the motorway, linking nearby Whitehall to Dublin Port.

The Eastern Bypass itself is a large infrastructure project, one estimate stated that it was 5 times the size of the €800 million Dublin Port Tunnel. It has been a consistent feature of Government publications for more than 40 years, at least as far back as An Foras Forbartha’s report: Transportation in Dublin in 1971.

The Route:The motorway will start at the Port Tunnel, run South across Dublin Bay, under Booterstown and then along through UCD, Goatstown and on to Sandyford to connect with the M50. It is too be noted that the Luas Green Line (the Dublin light rail system) directly connects to Sandyford Industrial estate and this siting was hardly accidental, given the-term planning involved with the Orbital Motorway.

The Regional Planning Guidelines for the Dublin Area (jointly prepared by the Regional Planning Guidelines Office, and the Dublin Regional Authority / Mid-East Regional Authority) listed this road in 2010. Dún Laoghaire-Rathdown County Council’s six-year development plan from 2010 also lists constructing the Eastern Bypass as an objective. These strategic planning decisions were made by elected councillors.

The 2014 Eastern Bypass proposed a protected alignment for “Sector A: Dublin [Port] Tunnel to Sandymount Strand” opens the possibility of running the motorway at-grade in the city area and shifts the route of the motorway so that it will run directly beside the Point Village as well as closer to residential areas in East Wall. The route will then cross over to the southside beside or as a replacement to the Eastlink Bridge, the proposed motorway alignment then runs between houses in Ringsend and the River Liffey.

Booterstown Section

The Inner Orbital road will pass the Irish Glass Bottle site (situated on its left) before reaching Sandymount Strand and then on to Booterstown where a tunnel or bridge would have to be constructed across the shoreline, land has long been reserved for this very purpose. The Booterstown section would act as a connector proceeding across the south grounds of UCD and on to Sandyford where it would connect with the current M50, completing the motorway ring inner road around Dublin city and suburbs. -

In 2016, Dublin City Council stated that it supported the new route section, and that they were in broad agreement with the overall plans and operational transport objectives. In fact, the council has confirmed the ongoing developmental status of the motorway in the city development plan. Dublin city councillors had excluded the bypass from the 2016-2022 draft plan, but it was nonetheless included in the final version. [3]

Cost Overruns of the Inner Orbital Route

From 1993 to 2013, this unbuilt 11 kilometer section of the M50 has seen its estimated cost rise from an estimated 268 million pounds in 1993 to 4 billion euro in 2013.

1993: £268 million (Dáil debate, 10/3/1993)

1999: £500 million (Irish Times)2000: £750 million (Irish Times)

2007: €1 billion (Irish Independent)

2013: €4 billion (National Roads Authority) [4]

Dublin Port and the Eastern Bypass

The semi-state Dublin Port Company has publicly supported the construction of an Eastern Bypass asserting that this would be an improvement on access to the Port’s hinterland as the company projects a doubling in port volumes to 2040. In 2014, the port company own master-plan projected a doubling in volume of freight requiring access to the Port. The Port has an actively used rail connection, however, the proportion of Port volumes using rail freight is only in the order of 1/60th due to the Port Tunnel.

In this regard, Dublin Port Company's public position is that such a projected doubling or trebling of port traffic would have minimal impact on the imposition which an overall doubling of port volumes would put on the road network. By this logic, the availability of a southern access route to the Port via an Eastern Bypass would somehow “complement" the Dublin Port Tunnel and would divide Port traffic between the two links in accordance with the cargoes’ origin and destination points. [5]

In an interesting development, in 2015, Dublin Port Company obtained planning permission for a new double cruise ship facility next to the Point Village. This had the potential to create a dual problem for both Dublin Port port and the orbital road, as large cruise ships accessing the port would theoretically block the Eastern Bypass from using a high bridge to cross the river Liffey. Instead, the project would have to use a tunnel or an East Link-style opening bridge, however., given the volume of traffic on the M50 an opening bridge seems an unlikely outcome. [6]

Government Policy & Plans

There is an extensive administrative history (10 official reports) concerning the Eastern Bypass/Inner-Orbital Route:

1. There are five formal policy statements referencing the Eastern Bypass. A Platform for Change, Strategy 2000 to 2016 (Dublin transportation Office) Dublin Docklands Area Masterplan 2008 Regional Planning Guidelines for the Greater Dublin Area 2010 to 2022 Dublin City Development Plan, 2011 to 2017. Dun Laoghaire Rathdown County Development Plan 2010 to 2016.

2. Also, five reports and draft plans addressing the Eastern Bypass: Dublin Eastern Bypass Feasibility Study Report, September 2007 (NRA) Dublin Eastern Bypass Corridor Protection Study Section A: Dublin Port Tunnel to Sandymount Strand, March 2009 (NRA) Dublin Eastern Bypass Corridor Protection Study Booterstown to Sandyford, January 2011 (NRA) Cruise Traffic Urban regeneration Local Action Plan, June 2011 (DCC, DPC and DDDA,). Greater Dublin Area Draft Transport Strategy 2011 to 2030, June 2011 (NTA).

A Dublin Port Report (6th March 2014) noted that the problematic timescale of the future Eastern Bypass, combined with restricted Government capital expenditure has the potential to create uncertainty in relation to other major and more immediate infrastructure projects such as Dublin Port's Alexandra Basin Redevelopment (ABR) Project. [7]

In 1992, Minister Michael Smith cancelled the Eastern Bypass under local political pressure. However it was subsequently revived when everyDublin City Councillor from the Fine Gael, Fianna Fail and Labour parties, voted to place it on the Dublin city 1999 development plan.

From Motorway to Greenway

In 2016, Dún Laoghaire-Rathdown county Council was in the process of drafting a new city development plan, a motion was proposed that the proposed motorway be eliminated as an objective from the plan, in fact this motion was defeated by two votes. As a compromise to deleting the motorway from the plan, councillors agreed to promote the use of the motorway reservation land as a greenway or cycleway or bus route while waiting for the state to proceed with its road plans. [8]

Eastern Bypass planned through Booterstown: In 2016, the National Transport Authority published a strategy for Dublin’s transport up to 2035. This states that the Eastern Bypass planned through the Booterstown Strand was not planned to be built before 2035 but that the land reservation should be preserved until then. As the land was first set aside in 1971, this will mean that the road reservation would have been kept for 64 years before construction commences on the final phase of the M50 Motorway.

In 2015, Transport Infrastructure Ireland formally replaced the National Roads Authority. In the same year, it requested Dún Laoghaire County Council to promise not to use the reservation for biodiversity projects or leisure uses “to ensure the future availability of said lands for when Bypass is eventually delivered.” On the 20th February 2016, councillors in a subsequent council vote agreed to remove the need for the NRA to approve letting use the planned motorway reservation at Booterstown for leisure and greenways. [9]

The Sandymount Cycle lane Overpass

In 2016, the National Transport Authority (NTA - successor to the National Roads Authority NRA) developed a sudden yearning for a combined road/cycle-lane interchange at the Merrion Gates Dublin-Area-Rapid-Transit (DART) rail junction on Strand Road, directly connecting and adjoining Rock Road / Booterstown Stand., and advanced a €48 million proposal. The NTA's proposal involves construction of an large underpass for use by cyclists and pedestrians with the closure of the level crossing to traffic.

The re-routed road traffic would access Merrion Road on a new road and bridge (overpass) over the coastal rail line further north through the car parks of the Merrion Hall office block on Strand Road and Our Lady Queen of Peace church on Merrion Road, which would be widened along with Rock Road with new 'segregated' cycling facilities. [10]

Is the Transport Authority simply Wrapping Old Fish at the Merrion Road?

In a further development, in 2019, it was announced that €17.5 million in funding was allocated for a section of the Dublin Bay greenway between Booterstown and Dún Laoghaire, according to the then-lord mayor of Dún Laoghaire Rathdown County Council, (Green Party) said: “Happy to announce that €17.5m has been allocated by the NTA for the S2S coastal greenway from Booterstown to Dún Laoghaire. Design and planning is underway.” When asked by a member of the public as to whether it would it be routed along the coast, the mayor replied “Mostly – the only section in doubt is from Blackrock to Merrion Gates and this is still being worked on.” However, this is the very section of relevance to the inner orbital (Eastern Bypass) road plan.

It is a fair question to ask if the Merrion Gates Interchange proposal is simply a means to push through an road overpass (with associated CPO land purchases at Strand and Merrion Roads) in the guise of a cycleway interchange at a crucial city road junction. Once planning permission is achieved, the road plan can rapidly be implemented, the original permission altered and the Bypass can be declared a national strategic infrastructure project with minimal planning process involved. The planned M20 motorway between Cork and Limerick is a good example of this continuous process.

The ongoing Eastern Bypass project is another example of how Dublin regional development is continuously subordinated to road development and rezoning. That this is a sensitive process in both planning and rezoning terms should be obvious as extensive tracts of invaluable city land on the south side of Dublin City are at stake. The experience with the famous M3 Motorway project, pushed through the ancient Tara Valley displays the determination of Government to sacrifice Ireland's environment and heritage to profit. [11]

(c) Irish Bulletin and Brian McGrath, 2020

[1] Dublin City Development Plan - 2016–2022 - Appropriate Assessment -, p.54. Also, 'What’s the 2016 plan for the Eastern Bypass motorway through Booterstown?' Ossian Smyth TD, February 10 2016,

[5] Alexandra Basin Redevelopment Project and a Possible Future Eastern Bypass - p.1.

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